Organic Structures from Spectra

Organic Structures from Spectra Fourth Edition

i

ii

Organic Structures from Spectra Fourth Edition

L D Field University of New South Wales, Australia

S Sternhell University of Sydney, Australia

J R Kalman University of Technology Sydney, Australia

JOHN WILEY AND SONS, LTD

Copyright © 2008

John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) 1243 779777

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CONTENTS _______________________________________________________________ PREFACE LIST OF TABLES LIST OF FIGURES 1 INTRODUCTION 1.1 1.2 1.3 1.4 1.5 1.6

GENERAL PRINCIPLES OF ABSORPTION SPECTROSCOPY CHROMOPHORES DEGREE OF UNSATURATION CONNECTIVITY SENSITIVITY PRACTICAL CONSIDERATIONS

2 ULTRAVIOLET (UV) SPECTROSCOPY 2.1 2.2 2.3 2.4 2.5 10 2.6 2.7

IMPORTANT UV CHROMOPHORES THE EFFECT OF SOLVENTS

10 14

ABSORPTION RANGE AND THE NATURE OF IR ABSORPTION EXPERIMENTAL ASPECTS OF INFRARED SPECTROSCOPY GENERAL FEATURES OF INFRARED SPECTRA IMPORTANT IR CHROMOPHORES

IONIZATION PROCESSES INSTRUMENTATION MASS SPECTRAL DATA REPRESENTATION OF FRAGMENTATION PROCESSES FACTORS GOVERNING FRAGMENTATION PROCESSES EXAMPLES OF COMMON TYPES OF FRAGMENTATION

5 NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY 5.1 5.2 5.3 5.4 5.5 5.6 5.7

7 7 8 8 9

4 MASS SPECTROMETRY 4.1 4.2 4.3 4.4 4.5 4.6

1 3 3 4 5 5

BASIC INSTRUMENTATION THE NATURE OF ULTRAVIOLET SPECTROSCOPY QUANTITATIVE ASPECTS OF ULTRAVIOLET SPECTROSCOPY CLASSIFICATION OF UV ABSORPTION BANDS SPECIAL TERMS IN ULTRAVIOLET SPECTROSCOPY

3 INFRARED (IR) SPECTROSCOPY 3.1 3.2 3.3 3.4

vii xi xiii 1

THE PHYSICS OF NUCLEAR SPINS AND NMR INSTRUMENTS CONTINUOUS WAVE (CW) NMR SPECTROSCOPY FOURIER-TRANSFORM (FT) NMR SPECTROSCOPY CHEMICAL SHIFT IN 1H NMR SPECTROSCOPY SPIN-SPIN COUPLING IN 1H NMR SPECTROSCOPY ANALYSIS OF 1H NMR SPECTRA RULES FOR SPECTRAL ANALYSIS

15 15 16 16 17 21 21 23 24 28 29 29 33 33 37 39 40 50 53 55

v

Contents

6 13C NMR SPECTROSCOPY 6.1 6.2 6.3

65 13C

COUPLING AND DECOUPLING IN NMR SPECTRA DETERMINING 13C SIGNAL MULTIPLICITY USING DEPT SHIELDING AND CHARACTERISTIC CHEMICAL SHIFTS IN 13C NMR SPECTRA

7 MISCELLANEOUS TOPICS

65 67 70 75

/

7.1 7.2 7.3 7.4 7.5 7.6

DYNAMIC PROCESSES IN NMR - THE NMR TIME-SCALE THE EFFECT OF CHIRALITY THE NUCLEAR OVERHAUSER EFFECT (NOE) TWO DIMENSIONAL NMR THE NMR SPECTRA OF "OTHER NUCLEI" SOLVENT - INDUCED SHIFTS

75 77 79 80 84 84

8 DETERMINING THE STRUCTURE OF ORGANIC MOLECULES FROM SPECTRA

85

9 PROBLEMS

89 89 373 383 419

9.1 9.2 9.3 9.4

ORGANIC STRUCTURES FROM SPECTRA THE ANALYSIS OF MIXTURES PROBLEMS IN 2-DIMENSIONAL NMR NMR SPECTRAL ANALYSIS

APPENDIX

444

INDEX

451

vi

PREFACE _______________________________________________________________

The derivation of structural information from spectroscopic data is an integral part of Organic Chemistry courses at all Universities. At the undergraduate level, the principal aim of such courses is to teach students to solve simple structural problems efficiently by using combinations of the major techniques (UV, IR, NMR and MS), and over more than 25 years we have evolved a course at the University of Sydney, which achieves this aim quickly and painlessly. The text is tailored specifically to the needs and philosophy of this course. As we believe our approach to be successful, we hope that it may be of use in other institutions. The course has been taught at the beginning of the third year, at which stage students have completed an elementary course of Organic Chemistry in first year and a mechanistically-oriented intermediate course in second year. Students have also been exposed in their Physical Chemistry courses to elementary spectroscopic theory, but are, in general, unable to relate it to the material presented in this course. The course consists of about 9 lectures outlining the theory, instrumentation and the structure-spectra correlations of the major spectroscopic techniques and the text of this book corresponds to the material presented in the 9 lectures. The treatment is both elementary and condensed and, not surprisingly, the students have great difficulties in solving even the simplest problems at this stage. The lectures are followed by a series of 2-hour problem solving seminars with 5 to 6 problems being presented per seminar. At the conclusion of the course, the great majority of the class is quite proficient and has achieved a satisfactory level of understanding of all methods used. Clearly, the real teaching is done during the problem seminars, which are organised in a manner modelled on that used at the E.T.H. Zurich. The class (typically 60 - 100 students, attendance is compulsory) is seated in a large lecture theatre in alternate rows and the problems for the day are identified. The students are permitted to work either individually or in groups and may use any written or printed aids they desire. Students solve the problems on their individual copies of this book thereby transforming it into a set of worked examples and we find that most students voluntarily complete many more problems than are set. Staff (generally 4 or 5) wander around giving help and tuition as needed, the empty alternate rows of seats

vii

Preface

making it possible to speak to each student individually. When an important general point needs to be made, the staff member in charge gives a very brief exposition at the board. There is a 11/2 hour examination consisting essentially of 4 problems and the results are in general very satisfactory. Moreover, the students themselves find this a rewarding course since the practical skills acquired are obvious to them. There is also a real sense of achievement and understanding since the challenge in solving the graded problems builds confidence even though the more difficult examples are quite demanding. Our philosophy can be summarised as follows: (a)

Theoretical exposition must be kept to a minimum, consistent with gaining of an understanding of the parts of the technique actually used in solving the problems. Our experience indicates that both mathematical detail and description of advanced techniques merely confuse the average student.

(b)

The learning of data must be kept to a minimum. We believe that it is more important to learn to use a restricted range of data well rather than to achieve a nodding acquaintance with more extensive sets of data.

(c)

Emphasis is placed on the concept of identifying "structural elements" and the logic needed to produce a structure out of the structural elements.

We have concluded that the best way to learn how to obtain "structures from spectra" is to practise on simple problems. This book was produced principally to assemble a collection of problems that we consider satisfactory for that purpose. Problems 1 – 277 are of the standard “structures from spectra” type and are arranged roughly in order of increasing difficulty. A number of problems are groups of isomers which differ mainly in the connectivity of the structural elements and these problems are ideally set together (e.g. problems 2 and 3, 22 and 23; 27 and 28; 29, 30 and 31; 40 and 41; 42 to 47; 48 and 49; 58, 59 and 60; 61, 62 and 63; 70, 71 and 72; 77 and 78; 80 and 81; 94, 95 and 96; 101 and 102; 104 to 107; 108 and 109; 112, 113 and 114; 116 and 117; 121 and 122; 123 and 124; 127 and 128; 133 to 137; 150 and 151; 171 and 172; 173 and 174; 178 and 179; 225, 226 and 227; 271 and 272; and 275 and 276). A number of problems exemplify complexities arising from the presence of chiral centres (e.g. problems 189, 190, 191, 192, 193, 222, 223, 242, 253, 256, 257, 258, 259, 260, 262, 265, 268, 269 and 270); or of restricted rotation about peptide or amide bonds (e.g. problems 122, 153 and 255), while other problems deal with structures of compounds of biological, environmental or industrial significance (e.g. problems 20, 21, 90, 121, 125, 126, 138, 147, 148, 153, 155, 180, 191, 197, 213, 252, 254, 256, 257, 258, 259, 260, 266, 268, 269 and 270).

viii

x

LIST OF TABLES _______________________________________________________________ Table 2.1 The Effect of Extended Conjugation on UV Absorption

11

Table 2.2

UV Absorption Bands in Common Carbonyl Compounds

12

Table 2.3

UV Absorption Bands in Common Benzene Derivatives

13

Table 3.1

Carbonyl IR Absorption Frequencies in Common Functional Groups

18

Table 3.2

Characteristic IR Absorption Frequencies for Common Functional Groups

19

Table 3.3

IR Absorption Frequencies in the Region 1900 – 2600 cm-1

20

Table 4.1

Accurate Masses of Selected Isotopes

25

Table 4.2

Common Fragments and their Masses

27

Table 5.1

Resonance Frequencies of 1H and 13C Nuclei in Magnetic Fields of Different Strengths

35

Table 5.2

Typical 1H Chemical Shift Values in Selected Organic Compounds

43

1

Table 5.3

Typical H Chemical Shift Ranges in Organic Compounds

44

Table 5.4

1

H Chemical Shifts (δ) for Protons in Common Alkyl Derivatives

44

Table 5.5

Approximate 1H Chemical Shifts (δ) for Olefinic Protons C=C-H

45

Table 5.6

1

H Chemical Shifts (δ) for Aromatic Protons in Benzene Derivatives PhX in ppm Relative to Benzene at δ 7.26 ppm

46

Table 5.7

1

H Chemical Shifts (δ) in some Polynuclear Aromatic Compounds and Heteroaromatic Compounds

46

Table 5.8

Typical 1H – 1H Coupling Constants

51

Table 5.9

Relative Line Intensities for Simple Multiplets

51

Table 5.10

Characteristic Multiplet Patterns for Common Organic Fragments

52

13

Table 6.1

The Number of Aromatic C Resonances in Benzenes with Different Substitution Patterns

69

Table 6.2

Typical 13C Chemical Shift Values in Selected Organic Compounds

70

Table 6.3

Typical 13C Chemical Shift Ranges in Organic Compounds

71

Table 6.4

13

C Chemical Shifts (δ) for sp3 Carbons in Alkyl Derivatives

72

Table 6.5

13

C Chemical Shifts (δ) for sp2 Carbons in Vinyl Derivatives

72

Table 6.6

13

C Chemical Shifts (δ) for sp Carbons in Alkynes: X-C≡C-Y

73

Table 6.7

Approximate 13C Chemical Shifts (δ) for Aromatic Carbons in Benzene Derivatives Ph-X in ppm relative to Benzene at δ 128.5 ppm

74

Table 6.8

Characteristic 13C Chemical Shifts (δ) in some Polynuclear Aromatic Compounds and Heteroaromatic Compounds

74

xi

xii

LIST OF FIGURES _______________________________________________________________ Figure 1.1

Schematic Absorption Spectrum

1

Figure 1.2

Definition of a Spectroscopic Transition

2

Figure 2.1

Schematic Representation of an IR or UV Spectrometer

7

Figure 2.2

Definition of Absorbance (A)

9

Figure 4.1

Schematic Diagram of an Electron-Impact Mass Spectrometer

23

Figure 5.1

A Spinning Charge Generates a Magnetic Field and Behaves Like a Small Magnet

33

Figure 5.2

Schematic Representation of a CW NMR Spectrometer

38

Figure 5.3

Time Domain and Frequency Domain NMR Spectra

39

Figure 5.4

Shielding/deshielding Zones for Common Non-aromatic Functional Groups

48

Figure 5.5

A Portion of the 1H NMR Spectrum of Styrene Epoxide (100 MHz as a 5% solution in CCl4)

57

Figure 5.6

The 60 MHz 1H NMR Spectrum of a 4-Spin AMX2 Spin System

58

Figure 5.7

Simulated 1H NMR Spectra of a 2-Spin System as the Ratio∆ν/J, is Varied from 10.0 to 0.0

59

Figure 5.8

Selective Decoupling in a Simple 4-Spin System

60

Figure 5.9

1

H NMR Spectrum of p-Nitrophenylacetylene (200 MHz as a 10% solution in CDCl3)

64

Figure 6.1

13

C NMR Spectra of Methyl Cyclopropyl Ketone (CDCl3 Solvent, 100 MHz). (a) Spectrum with Full Broad Band Decoupling of 1H ; (b) DEPT Spectrum (c) Spectrum with no Decoupling of 1H; (d) SFORD Spectrum

68

Figure 7.1

Schematic NMR Spectra of Two Exchanging Nuclei

75

Figure 7.2

1

78

H NMR Spectrum of the Aliphatic Region of Cysteine Indicating Nonequivalence of the Methylene Protons due to the Influence of the Stereogenic Centre

xiii

xiv

1 INTRODUCTION

1.1

GENERAL PRINCIPLES OF ABSORPTION SPECTROSCOPY

The basic principles of absorption spectroscopy are summarised below. These are most obviously applicable to UV and IR spectroscopy and are simply extended to cover NMR spectroscopy. Mass Spectrometry is somewhat different and is not a type of absorption spectroscopy. Spectroscopy is the study of the quantised interaction of energy (typically

electromagnetic energy) with matter. In Organic Chemistry, we typically deal with molecular spectroscopy i.e. the spectroscopy of atoms that are bound together in molecules. A schematic absorption spectrum is given in Figure 1.1. The absorption spectrum is a plot of absorption of energy (radiation) against its wavelength (A.) or frequency (v).

/

t

intensity of transmitted light

absorption intensity

~ I.:

,

absorption maximum

v ~E

Figure 1.1

Schematic Absorption Spectrum

1

Chapter 1 Introduction

An absorption band can be characterised primarily by two parameters: (a)

the wavelength at which maximum absorption occurs

(b)

the intensity of absorption at this wavelength compared to base-line (or background) absorption

A spectroscopic transition takes a molecule from one state to a state of a higher energy. For any spectroscopic transition between energy states (e.g. E 1 and Ez in Figure 1.2), the change in energy

(~E)

is given by: ~E=hv

where h is the Planck's constant and v is the frequency of the electromagnetic energy absorbed. Therefore v a: ~E.

i

t

Energy

Figure 1.2

Definition of a Spectroscopic Transition

It follows that the x-axis in Figure 1.1 is an energy scale, since the frequency,

wavelength and energy of electromagnetic radiation are interrelated: vA. = c (speed of light) A.=£ v

1 A.oc~E

A spectrum consists of distinct bands or transitions because the absorption (or emission) of energy is quantised. The energy gap of a transition is a molecular property and is characteristic ofmolecular structure. The y-axis in Figure 1.1 measures the intensity of the absorption band and this depends on the number of molecules observed (the Beer-Lambert Law) and the probability of the transition between the energy levels. The absorption intensity is

2

Chapter 1 Introduction

also a molecular property and both the frequency and the intensity of a transition can provide structural information.

1.2

CHROMOPHORES

In general, any spectral feature, i.e. a band or group of bands, is due not to the whole molecule, but to an identifiable part of the molecule, which we loosely call a chromophore.

A chromophore may correspond to a functional group (e.g. a hydroxyl group or the double bond in a carbonyl group). However, it may equally well correspond to a single atom within a molecule or to a group of atoms (e.g. a methyl group) which is . not normally associated with chemical functionality. The detection of a chromophore permits us to deduce the presence of a structural fragment or a structural element in the molecule. The fact that it is the chromophores

and not the molecules as a whole that give rise to spectral features is fortunate, otherwise spectroscopy would only permit us to identify known compounds by direct comparison of their spectra with authentic samples. This "fingerprint" technique is often useful for establishing the identity of known compounds, but the direct determination of molecular structure building up from the molecular fragments is far more powerful.

1.3

DEGREE OF UNSATURATION

Traditionally, the molecular formula of a compound was derived from elemental analysis and its molecular weight which was determined independently. The concept of the degree of unsaturation of an organic compound derives simply from the tetravalency of carbon. For a non-cyclic hydrocarbon (i.e. an alkane) the number of hydrogen atoms must be twice the number of carbon atoms plus two, any "deficiency" in the number of hydrogens must be due to the presence of unsaturation, i.e. double bonds, triple bonds or rings in the structure. The degree of unsaturation can be calculated from the molecular formula for all compounds containing C, H, N, 0, S or the halogens. There are 3 basic steps in calculating the degree of unsaturation: Step 1 - take the molecular formula and replace all halogens by hydrogens Step 2 - omit all of the sulfur or oxygen atoms

3

Chapter 1 Introduction

Step 3 - for each nitrogen, omit the nitrogen and omit one hydrogen After these 3 steps, the molecular formula is reduced to CoHm and the degree of unsaturation is given by: Degree of Unsaturation = n _...!!1..- + 1 2

The degree of unsaturation indicates the number of 1t bonds or rings that the compound contains. For example, a compound whose molecular formula is CJi9NOz is reduced to C4Hg which gives a degree of unsaturation of I and this indicates that the molecule must have one 1t bond or one ring. Note that any compound that contains an aromatic ring always has a degree of unsaturation greater than or equal to 4, since the aromatic ring contains a ring plus three

1t

bonds. Conversely if a compound has a

degree of unsaturation greater than 4, one should suspect the possibility that the structure contains an aromatic ring.

1.4

CONNECTIVITY

Even if it were possible to identify sufficient structural elements in a molecule to account for the molecular formula, it may not be possible to deduce the structural formula from a knowledge of the structural elements alone. For example, it could be demonstrated that a substance of molecular formula C3HsOCI contains the structural elements: -CH 3 -CI

and this leaves two possible structures:

CH -C-CH -CI 3

II

a 1

2

CH -CH -C-CI and

3

2

II

o 2

Not only the presence of various structural elements, but also their juxtaposition must be determined to establish the structure of a molecule. Fortunately, spectroscopy often gives valuable information concerning the connectivity of structural elements

4

Chapter 1 Introduction

and in the above example it would be very easy to determine whether there is a ketonic carbonyl group (as in 1) or an acid chloride (as in 2). In addition, it is possible to determine independently whether the methyl (-CH 3) and methylene (-CHz-) groups are separated (as in 1) or adjacent (as in 2).

1.5

SENSITIVITY

Sensitivity is generally taken to signify the limits of detectability of a chromophore. Some methods (e.g. 'H NMR) detect all chromophores accessible to them with equal sensitivity while in other techniques (e.g. UV) the range of sensitivity towards different chromophores spans many orders of magnitude. In terms of overall sensitivity, i.e. the amount of sample required, it is generally observed that: MS > UV > IR> lH NMR > BC NMR but considerations of relative sensitivity toward different chromophores may be more important.

1.6

PRACTICAL CONSIDERATIONS

The 5 major spectroscopic methods (MS, UV, IR, lH NMR and BC NMR) have become established as the principal tools for the determination of the structures of organic compounds, because between them they detect a wide variety of structural ,/

elements. The instrumentation and skills involved in the use of all five major spectroscopic methods are now widely spread, but the ease of obtaining and interpreting the data from each method under real laboratory conditions varies. In very general terms: (a)

While the cost of each type of instrumentation differs greatly (NMR instruments cost between $50,000 and several million dollars), as an overall guide, MS and NMR instruments are much more costly than UV and IR spectrometers. With increasing cost goes increasing difficulty in maintenance, thus compounding the total outlay.

(b)

In terms of ease ofusage for routine operation, most UV and IR instruments are comparatively straightforward. NMR Spectrometers are also common as "hands-on" instruments in most chemistry laboratories but the users require some training, computer skills and expertise. Similarly some Mass Spectrometers are now designed to be used by researchers as "hands-on" routine

5

Chapter 1 Introduction

instruments. However, the more advanced NMR Spectrometers and most Mass Spectrometers are sophisticated instruments that are usually operated by specialists. (c)

The scope of each method can be defined as the amount of useful information it provides. This is a function not only of the total amount of information obtainable, but also how difficult the data are to interpret. The scope of each method varies from problem to problem and each method has its aficionados and specialists, but the overall utility undoubtedly decreases in the order: NMR> MS > IR > UV with the combination of IH and I3C NMR providing the most useful information.

(d)

The theoretical background needed for each method varies with the nature of the experiment, but the minimum overall amount of theory needed decreases in the order: NMR» MS >UV:::::IR

6

Chapter 2 Ultraviolet Spectroscopy

2

ULTRAVIOLET (UV) SPECTROSCOPY 2.1

BASIC INSTRUMENTATION

Basic instrumentation for both UV and IR spectroscopy consists of an energy source, a sample cell, a dispersing device (prism or grating) and a detector, arranged as schematically shown in Figure 2.1.

dispersing device or prism

O~

•

~

radiation source

...

U

~

-: ~

slit detector

I ----. I

sample

spectrum

t I

I

Figure 2.1

--).-

Schematic Representation of an IR or UV Spectrometer

The drive of the dispersing device is synchronised with the x-axis of the recorder or fed directly to a computer, so that this indicates the wavelength of radiation reaching the detector. The signal from the detector is transmitted to the y-axis of the recorder or to a computer and this indicates how much radiation is absorbed by the sample at any particular wavelength.

7

Chapter 2 Ultraviolet Spectroscopy

In practice, double-beam instruments are used where the absorption of a reference

cell, containing only solvent, is subtracted from the absorption of the sample cell. Double beam instruments also cancel out absorption due to the atmosphere in the optical path as well as the solvent. The energy source, the materials from which the dispersing device and the detector are constructed must be appropriate for the range of wavelength scanned and as transparent as possible to the radiation. For UV measurements, the cells and optical components are typically made of quartz and ethanol, hexane, water or dioxan are usually chosen as solvents.

2.2

THE NATURE OF ULTRAVIOLET SPECTROSCOPY

The term "UV spectroscopy" generally refers to electronic transitions occurring in the region of the electromagnetic spectrum (A in the range 200-380 nm) accessible to standard UV spectrometers. Electronic transitions are also responsible for absorption in the visible region (approximately 380-800 nm) which is easily accessible instrumentally but ofless importance in the solution of structural problems, because most organic compounds are colourless. An extensive region at wavelengths shorter than

~

200 nm ("vacuum

ultraviolet") also corresponds to electronic transitions, but this region is not readily accessible with standard instruments. . UV spectra used for determination of structures are invariably obtained in solution.

2.3

QUANTITATIVE ASPECTS OF ULTRAVIOLET SPECTROSCOPY

The y-axis of a UV spectrum may be calibrated in terms of the intensity of transmitted light (i.e. percentage of transmission or absorption), as is shown in Figure 2.2, or it may be calibrated on a logarithmic scale i.e. in terms of absorbance (A) defined in Figure 2.2. Absorbance is proportional to concentration and path length (the Beer-Lambert Law). The intensity of absorption is usually expressed in terms of molar absorbance or the

molar extinction coefficient (e) given by:

E

= MA CI

where M is the molecular weight, C the concentration (in grams per litre) and I is the path length through the sample in centimetres.

8

Chapter 2 Ultraviolet Spectroscopy

i

UV

absorption band

Intensity of transmitted light

10 A=IOQ1O -

1

:t..max t.. (nm)

Figure 2.2

~

Definition of Absorbance (A)

UV absorption bands (Figure 2.2) are characterised by the wavelength of the absorption maximum (Amax ) and E. The values of Eassociated with commonly encountered chromophores vary between 10 and 105 • For convenience, extinction coefficients are usually tabulated as 10glO(E) as this gives numerical values which are easier to manage. The presence of small amounts of strongly absorbing impurities may lead to errors in the interpretation ofUV data.

2.4

CLASSIFICATION OF UV ABSORPTION BANDS

UV absorption bands have fine structure due to the presence of vibrational sub-levels, but this is rarely observed in solution due to collisional broadening. As the transitions are associated with changes of electron orbitals, they are often described in terms of the orbitals involved, e.g. 0' ~ 0'* 1t ~ 1t*

n

~ 1t*

n

~ 0'*

where n denotes a non-bonding orbital, the asterisk denotes an antibonding orbital and 0'

and

1t

have the usual significance.

Another method of classification uses the symbols: B

(for benzenoid)

E

(for ethylenic)

R

(for radical-like)

K

(for conjugated - from the German "konjugierte'')

9

Chapter 2 Ultraviolet Spectroscopy

A molecule may give rise to more than one band in its UV spectrum, either because it contains more than one chromophore or because more than one transition of a single chromophore is observed. However, UV spectra typically contain far fewer features (bands) than IR, MS or NMR spectra and therefore have a lower information content. The ultraviolet spectrum of acetophenone in ethanol contains 3 easily observed bands:

Amax

loglO(e)

Assignment

(nm)

0

II

OC'CH

3

acetophenone

2.5

244

12,600

4.1

280

1,600

3.2

317

60

1.8

n---+ n* n---+ n* n ---+ n*

K

B R

SPECIAL TERMS IN UV SPECTROSCOPY

Auxochromes (auxiliary chromophores) are groups which have little UV absorption

by themselves, but which often have significant effects on the absorption (both Amax and E) of a chromophore to which they are attached. Generally, auxochromes are atoms with one or more lone pairs e.g. -OH, -OR, -NR z, -halogen. / If a structural change, such as the attachment of an auxochrome, leads to the absorption maximum being shifted to a longer wavelength, the phenomenon is termed a bathochromic shift. A shift towards shorter wavelength is called a hypsochromic shift.

2.6

IMPORTANT UV CHROMOPHORES

Most of the reliable and useful data is due to relatively strongly absorbing chromophores (E > 200) which are mainly indicative of conjugated or aromatic systems. Examples listed below encompass most of the commonly encountered effects.

10

I

l

I

Chapter 2 Ultraviolet Spectroscopy

(1)

Dienes and Polyenes

Extension of conjugation in a carbon chain is always associated with a pronounced shift towards longer wavelength, and usually towards greater intensity (Table 2.1).

Table 2.1

The Effect of Extended Conjugation on UV Absorption

Alkene

Amax (nm)

e

10glO(£)

CH 2=CH 2

165

10,000

4.0

CH 3-CH 2-CH=CH-CH 2-CH 3 (trans)

184

10,000

4.0

CH2=CH-CH=CH 2

217

20,000

4.3

CH 3-CH=CH-CH=CH 2 (trans)

224

23,000

4.4

CH2=CH-CH=CH-CH=CH 2 (trans)

263

53,000

4.7

CH 3-(CH=CH)s-CH 3 (trans)

341

126,000

5.1

When there are more than 8 conjugated double bonds, the absorption maximum of polyenes is such that they absorb light strongly in the visible region of the spectrum. Empirical rules (Woodward's Rules) of good predictive value are available to estimate the positions of the absorption maxima in conjugated alkenes and conjugated carbonyl compounds. The stereochemistry and the presence of substituents also influence UV absorption by the diene chromophore. For example:

co

o

Arnax = 214 run

Arnax = 253 run

E=

16,000

10glO(E) = 4.2

E

= 8,000

10glO(E) = 3.9

11

Chapter 2 Ultraviolet Spectroscopy

(2)

Carbonyl compounds

All carbonyl derivatives exhibit weak (e < 100) absorption between 250 and 350 nm, and this is only of marginal use in determining structure. However, conjugated carbonyl derivatives always exhibit strong absorption (Table 2.2).

Table 2.2

UV Absorption Bands in Common Carbonyl Compounds

Compound Acetaldehyde

Structure CH3 ,

C

'i 0

I

CH3, ",0

I CH3

I

CH/'C,C'i° I

H

C

-::::-

t

-,

I

c'"

CH3

H I

CHh

'ic, ",0 C c'" I

CH3

12

. . . :: °

I

H

4-Methylpent-3-en-2-one

12

1.1

15

1.2

207

12,000

4.1

328

20

.1.3

221

12,000

4.1

312

40

1.6

238

12,000

4.1

316

60

1.8

(ethanol solution)

H CH3,

293

(hexane solution)

H

(E)-Pent-3-en-2-one

IOglO(E)

279

c'"

Propenal

E

(hexane solution)

H

Acetone

Amax(nm)

I

CH3

(ethanol solution)

(ethanol solution)

Cyc1ohex-2-en-l-one

0 0

225

7,950

3.9

Benzoquinone

000

247

12,600

4.1

292

1,000

3.0

363

250

2.4

Chapter 2 Ultraviolet Spectroscopy

(3)

Benzene derivatives

Benzene derivatives exhibit medium to strong absorption in the UV region. Bands usually have characteristic fine structure and the intensity of the absorption is strongly influenced by substituents. Examples listed in Table 2.3 include weak auxochromes (-CH 3 , -CI, -OCH 3) , groups which increase conjugation (-CH==CH z, -C(==O)-R, -N0 2) and auxochromes whose absorption is pH dependent (-NH z and -OH).

Table 2.3

UV Absorption Bands in Common Benzene Derivatives

Amax (nm)

s

loglO(e)

184 204 256

60,000 7,900 200

4.8 3.9 2.3

208 261

8,000 300

3.9 2.5

216 265

8,000 240

3.9 2.4

220 272

8,000 1,500

3.9 3.2

o-CH= CH2

244 282

12,000 450

4.1 2.7

Q-\1-CH3

244 280

12,600 1,600

4.1 3.2

o-NO:!

251 280 330

9,000 1,000 130

4.0 3.0 2.1

o-

NH2

230 281

8,000 1,500

3.9 3.2

Ani1iniurn ion

0-~H3

203 254

8,000 160

3.9 2.2

Phenol

o-0H 0-0

211 270

6,300 1,500

3.8 3.2

235 287

9,500 2,500

4.0 3.4

Compound Benzene

Toluene

Ch1orobenzene

Anisole

Styrene Acetophenone

Structure

0

o-CH3 o-CI 0-0CH3 0

Nitrobenzene

"i

q~

~~

,

Aniline

'it

"

'~h

.'i'

Phenoxide ion

., N~'

~1'

13

Chapter 2 Ultraviolet Spectroscopy

Aniline and phenoxide ion have strong UV absorptions due to the overlap of the lone pair on the nitrogen (or oxygen) with the n-system of the benzene ring. This may be expressed in the usual Valence Bond terms:

The striking changes in the ultraviolet spectra accompanying protonation of aniline and phenoxide ion are due to loss (or substantial reduction) of the overlap between the lone pairs and the benzene ring.

2.7

THE EFFECT OF SOLVENTS

Solvent polarity may affect the absorption characteristics, in particular Amax, since the polarity of a molecule usually changes when an electron is moved from one orbital to another. Solvent effects of up to 20 nm may be observed with carbonyl compounds. Thus the n ~ n* absorption of acetone occurs at 279 nm in n-hexane, 270 nm in ethanol, and at 265 nm in water.

14

Chapter 3 Infrared Spectroscopy

3 INFRARED (IR) SPECTROSCOPY

3.1

ABSORPTION RANGE AND THE NATURE OF IR ABSORPTION

Infrared absorption spectra are calibrated in wavelengths expressed in micrometers: Ium = 10-6 m

or in frequency-related wave numbers (crrrU which are reciprocals of wavelengths: _

wave number

v

1 x 10

-1

(em ) =

4

wavelength (in urn)

The range accessible for standard instrumentation is usually:

v or A

=:

4000 to 666 crrr!

=:

2.5 to 15 urn

Infrared absorption intensities are rarely described quantitatively, except for the general classifications of s (strong), m (medium) or w (weak). The transitions responsible for IR bands are due to molecular vibrations, i.e. to periodic motions involving stretching or bending of bonds. Polar bonds are associated with strong IR absorption while symmetrical honds may not absorb at all. Clearly the vibrational frequency, i.e. the position of the IR bands in the spectrum, depends on the nature of the bond. Shorter and stronger bonds have their stretching vibrations at the higher energy end (shorter wavelength) of the IR spectrum than the longer and weaker bonds. Similarly, bonds to lighter atoms (e.g. hydrogen), vibrate at higher energy than bonds to heavier atoms. IR bands often have rotational sub-structure, but this is normally resolved only in spectra taken in the gas phase.

15

Chapter 3 Infrared Spectroscopy

3.2

EXPERIMENTAL ASPECTS OF INFRARED SPECTROSCOPY

The basic layout of a simple dispersive IR spectrometer is the same as for an UV spectrometer (Figure 2.1), except that all components must now match the different energy range of electromagnetic radiation. The more sophisticated Fourier Transform Infrared (FTIR) instruments record an infrared interference pattern generated by a moving mirror and this is transformed by a computer into an infrared spectrum. Very few substances are transparent over the whole of the IR range: sodium and potassium chloride and sodium and potassium bromide are most cornmon. The cells used for obtaining IR spectra in solution typically have NaCl windows and liquids can be examined as films on NaCl plates. Solution spectra are generally obtained in chloroform or carbon tetrachloride but this leads to loss of information at longer wavelengths where there is considerable absorption of energy by the solvent. Organic solids may also be examined as mulls (fine suspensions) in heavy oils. The oils absorb infrared radiation but only in well-defined regions of the IR spectrum. Solids may also be examined as dispersions in compressed KBr or KCl discs. To a first approximation, the absorption frequencies due to the important IR chromophores are the same in solid and liquid states.

3.3

GENERAL FEATURES OF INFRARED SPECTRA

'Almost all organic compounds contain C-H bonds and this means that there is invariably an absorption band in the IR spectrum between 2900 and 3100 ern" at the C-H stretching frequency. Molecules generally have a large number of bonds and each bond may have several IR-active vibrational modes. IR spectra are complex and have many overlapping absorption bands. IR spectra are sufficiently complex that the spectrum for each compound is unique and this makes IR spectra very useful for identifying compounds by direct comparison with spectra from authentic samples t'fingerprinting'Y. The characteristic IR vibrations are influenced strongly by small changes in molecular structure, thus making it difficult to identify structural fragments from IR data alone. However, there are some groups of atoms that are readily recognised from IR spectra.

IR chromophores are most useful for the determination of structure if: (a)

The chromophore does not absorb in the most crowded region of the spectrum (600-1400 crrr ') where strong overlapping stretching absorptions from C-X single bonds (X = 0, N, S, P and halogens) make assignment difficult.

16

Chapter 3 Infrared Spectroscopy

(b)

The chromophores should be strongly absorbing to avoid confusion with weak harmonics. However, in otherwise empty regions e.g. 1800-2500 cm', even weak absorptions can be assigned with confidence.

(c)

The absorption frequency must be structure dependent in an interpretable manner. This is particularly true of the very important bands due to the C=O stretching vibrations, which generally occur between 1630 and 1850 em".

3.4

IMPORTANT IR CHROMOPHORES

(1)

-O-H Stretch

Not hydrogen-bonded ("free")

3600 cm'

Hydrogen-bonded

3100 - 3200 crrr!

This difference between hydrogen bonded and free OH frequencies is clearly related to the weakening of the O-H bond as a consequence of hydrogen bonding.

(2)

Carbonyl groups always give rise to strong absorption between 1630 and

1850 crrr! due to C=O stretching vibrations. Moreover, carbonyl groups in different functional groups are associated with well-defined regions ofIR absorption (Table 3.1). Even though the ranges for individual types often overlap, it may be possible to make a definite decision from information derived from other regions of the IR spectrum. Thus esters also exhibit strong C-O stretching absorption between 1200 and 1300 crrr! while carboxylic acids exhibit O-H stretching absorption generally near 3000 cm'. The characteristic shift toward lower frequency associated with the introduction of

a, p-unsaturation can be rationalised by considering the Valence Bond description of an enone:

"

"

c=c

/c=o

/'"

A

"

,,+ -

c=c

/c-o ---

/'" B

" ,,+c-c~.;.:c-o

/'" c

The additional structure C, which cannot be drawn for an unconjugated carbonyl derivative, implies that the carbonyl band in an enone has more single bond character and is therefore weaker. The involvement of a carbonyl group in hydrogen bonding reduces the frequency of the carbonyl stretching vibration by about 10 cm-'. This can be rationalised in a manner analogous to that proposed above for free and H-bonded O-H vibrations.

17

Chapter 3 Infrared Spectroscopy

Table 3.1

Carbonyl (C=O) IR Absorption Frequencies in Common Functional Groups

Carbonyl group

Structure

V (crn")

Ketones

R-C-R'

1700 - 1725

II

a Aldehydes

1720 - 1740

R-C-H

a"

Aryl aldehydes or ketones, a, f3-unsaturated aldehydes or ketones

Ar-C-R'

o"

R' = alkyl, aryl, or H

R~C-R'

o"

0=0

Cyc1opentanones

1660 - 1715

1740 - 1750

Cyc1obutanones

0=0

1760 - 1780

Carboxylic acids

R-C-OH

1700 - 1725

1\

a a, f3-unsaturated and aryl

Ar-C-OH

carboxylic acids

II

Esters

1680 - 1715

o 1735 - 1750

R-C-OR'

§

II

a Phenolic Esters

§

Aryl or a, f3-unsaturated Esters § o-Lactones

§

y- Lactones

§

Amides

R-C-OAr

1760 - 1800

R~C-OR' Ar-C-OR' II

1715 - 1730

a"

It

o

0

0=0

1735 - 1750

c5=0

1760 - 1780

R-C-NR'R"

1630 - 1690

II

a Acid chlorides

R-C-CI II

1785 - 1815

a Acid anhydrides (two bands) Carboxy1ates

R-C-O-C-R II

II

o a ... 9 R-C ("<, "

o

1740 - 1850 1550 - 1610 1300 - 1450

§ Esters and 1actones also exhibit a strong C-O stretch in the range 1160 - 1250 cm- 1

18

Chapter 3 Infrared Spectroscopy

(3)

Other polar functional groups. Many functional groups have characteristic

IR absorptions (Table 3.2). These are particularly useful for groups that do not contain magnetic nuclei and are thus not readily identified by NMR spectroscopy.

Table 3.2

Characteristic IR Absorption Frequencies for Common Functional Groups

Functional group

V (em:")

Structure -,

Amine

3300 - 3500

. . . . N-H

Terminal acetylenes

=C-H

3300

Irnines

"/ . . . . C=N

1480 - 1690

"c=c

Enol ethers

Intensity

strong

1600 - 1660

strong

Alkenes

1640 - 1680

weak to medium

Nitro groups

1500 - 1650 1250 - 1400

strong medium

1010 - 1070

strong

1300 - 1350 1100 - 1150

strong strong

1140 - 1180 1300 - 1370

strong strong

/

/

"-

O-R

-,

Sulfoxides

. . . . 5=0 I

Sulfones

O=S=O

I

Sulfonamides and Sulfonate esters Alcohols

)

-so2 -N "-.......- S0 2- 0-,

-C-OH

)

)

1000 - 1260

strong

1085 - 1150

strong

1000 - 1400

strong

580 - 780

strong

560 - 800

strong

500 - 600

strong

)

/

Ethers

\

-C-OR /

Alkyl fluorides

\

-C-F /

Alkyl chlorides

\

-C-C1 /

Alkyl bromides

\

-C-Br /

Alkyl iodides

\

-C-I /

19

Chapter 3 Infrared Spectroscopy

Carbon-carbon double bonds in unconjugated alkenes usually exhibit weak to moderate absorptions due to C=C stretching in the range 1660-1640 em". Disubstituted, trisubstituted and tetrasubstituted alkenes usually absorb near 1670 em". The more polar carbon-carbon double bonds in enol ethers and enones usually absorb strongly between 1600 and 1700 em-I. Alkenes conjugated with an aromatic ring absorb strongly near 1625 cm-'.

(4)

Chromophores absorbing in the region between 1900 and 2600 em:'. The

absorptions listed in Table 3.3 often yield useful information because, even though some are of only weak or medium intensity, they occur in regions largely devoid of absorption by other commonly occurring chromophores.

Table 3.3

IR Absorption Frequencies in the Region 1900 - 2600 em"

Functional group

Structure

V (ern:")

Intensity

Alkyne

-c=c-

2100 - 2300

weak to medium

Nitrile

-C=N

- 2250

medium

Cyanate

-N=C=O

- 2270

strong

Isocyanate

-N=C=O

2200 - 2300

strong

Thiocyanate

-N=C=S

- 2150 (broad)

strong

- 1950

strong

Allene

\ I

20

I

C=C=C

\

Chapter 4 Mass Spectrometry

4 MASS SPECTROMETRY

It is possible to determine the masses of individual ions in the gas phase. Strictly

speaking, it is only possible to measure their mass/charge ratio (m/e), but as multi charged ions are very much less abundant than those with a single electronic charge

.(e

=

I), m/e is for all practical purposes equal to the mass of the ion, m. The principal

experimental problems in mass spectrometry are firstly to volatilise the substrate (which implies high vacuum) and secondly to ionise the neutral molecules to charged species.

4.1

IONISATION PROCESSES

The most common method of ionisation involves Electron Impact (EI) and there are two general courses of events following a collision of a molecule M with an electron

e. By far the most probable event involves electron ejection which yields an odd-electron positively charged cation radical [M]+' of the same mass as the initial molecule M.

M+e

~

[M]+'

+ 2e

The cation radical produced is known as the molecular ion and its mass gives a direct measure of the molecular weight of a substance. An alternative, far less probable process, also takes place and it involves the capture of an electron to give a negative

anion radical, [M]-·. M+e

~

[M]-'

Electron impact mass spectrometers are generally set up to detect only positive ions, but negative-ion mass spectrometry is also possible. The energy of the electron responsible for the ionisation process can be varied. It must be sufficient to knock out an electron and this threshold, typically about 10-12 eV, is known as the appearance potential. In practice much higher energies

(-70 eV) are used and this large excess energy (1 eV

=

95 kJ moll) causes further

fragmentation of the molecular ion.

21

Chapter 4 Mass Spectrometry

The magnetic scan is synchronised with the x-axis of a recorder and calibrated to appear as mass number (strictly m/e). The amplified current from the ion collector gives the relative abundance of ions on the y-axis. The signals are usually preprocessed by a computer that assigns a relative abundance of 100% to the strongest peak (base peak).

Many modern mass spectrometers do not use a magnet to bend the ion beam to separate ions but rather use the "time offlight" (TOF) of an ion over a fixed distance to measure its mass. In these spectrometers, ions are generated (usually using a very short laser pulse) then accelerated in an electric field. Lighter ions have a higher velocity as they leave the accelerating field and their time of flight over a fixed distance will vary depending on the speed that they are travelling. Time of Flight mass spectrometers have the advantage that they do not require large, high-precision magnets to bend and disperse the ion beam so they tend to be much smaller, compact and less complex (desk-top size) instruments.

4.3

MASS SPECTRAL DATA

As well as giving the molecular weight of a substance, the molecular ion of a compound may provide additional information. The "nitrogen rule" states that a molecule with an even molecular weight must contain no nitrogen atoms or an even number of nitrogen atoms. This means that a molecule with an odd molecular weight must contain an odd number of nitrogen atoms. (1)

High resolution mass spectra. The mass of an ion is routinely determined to

the nearest unit value. Thus the mass of [M]+ gives a direct measure of molecular weight. It is not usually possible to assign a molecular formula to a compound on the basis of the integer m/e value of its parent ion. For example, a parent ion at m/e 72 could be due to a compound whose molecular formula is C4Hp or one with a molecular formula C3H40 Z or one with a molecular formula C 3HgNZHowever, using a double-focussing mass spectrometer or a time-of-flight mass spectrometer, the mass of an ion or any fragment can be determined to an accuracy of approximately ± 0.00001 of a mass unit (a high resolution mass spectrum). Since the masses of the atoms of each element are known to high accuracy, molecules that may have the same mass when measured only to the nearest integer mass unit, can be distinguished when the mass is measured with high precision. Based on the accurate masses of IZC, 160, 14N and IH (Table 4.1) ions with the formulas C4HgO+·, C3H40Z+or C3HgNt - would have accurate masses 72.0573, 72.0210, and 72.0686 so these

24

Chapter 4 Mass Spectrometry

4.2

INSTRUMENTATION

In a magnetic sector mass spectrometer (Figure 4.1), the positively charged ions of mass, m, and charge, e (generally e = 1) are subjected to an accelerating voltage V and passed through a magnetic field H which causes them to be deflected into a curved path of radius r. The quantities are connected by the relationship: 2

H r2

m =

e

2V

The values of H and V are known, r is determined experimentally and e is assumed to be unity thus permitting us to determine the mass m. In practice the magnetic field is scanned so that streams of ions of different mass pass sequentially to the detecting system (ion collector). The whole system (Figure 4.1) is under high vacuum (less than 10-6 Torr) to permit the volatilisation of the sample and so that the passage of ions is not impeded. The introduction of the sample into the ion chamber at high vacuum requires a complex sample inlet system.

Beam of positively charged ions

Ion Colle ctor

Electron Beam

Mass spectrum

t

Relative abundance ('Yo)

I

Base Peak (100%)

[M]....

III III

I

---

I

--mle_

Figure 4.1

Schematic Diagram of an Electron-Impact Mass Spectrometer

23

Chapter 4 Mass Spectrometry

The two important types of fragmentation are: A+ (even electron cation) + B' (radical) or C+' (cation radical) + D (neutral molecule) As only species bearing a positive charge will

b~

detected, the mass spectrum will

show signals due not only to [M]+' but also due to A+, C+' and to fragment ions resulting from subsequent fragmentation of A+and C+·. As any species may fragment in a variety of ways, the typical mass spectrum consists of many signals. The mass spectrum consists of a plot of masses of ions against their relative abundance. There are a number of other methods for ionising the sample in a mass spectrometer. The most important alternative ionisation method to electron impact is Chemical Ionisation (CI). In CI mass spectrometry, an intermediate substance (generally methane or ammonia) is introduced at a higher concentration than that of the substance being investigated. The carrier gas is ionised by electron impact and the substrate is then ionised by collisions with these ions. CI is a milder ionisation method than EI and leads to less fragmentation of the molecular ion. Another common method of ionisation is Electrospray Ionisation (ES). In this method, the sample is dissolved in a polar, volatile solvent and pumped through a fine -' metal nozzle, the tip of which is charged with a high voltage. This produces charged droplets from which the solvent rapidly evaporates to leave naked ions which pass into the mass spectrometer. ES is also a relatively mild form of ionisation and is very suitable for biological samples which are usually quite soluble in polar solvent but which are relatively difficult to vaporise in the solid state. Electrospray ionisation tends to lead to less fragmentation of the molecular ion than EI. Matrix Assisted Laser Desorption Ionisation (MALDI) uses a pulse of laser light to bring about ionisation. The sample is usually mixed with a highly absorbing compound which acts as a supporting matrix. The laser pulse ionises and vaporises the matrix and the sample to give ions which pass into the mass spectrometer. Again MALDI is a relatively mild form of ionisation which tends to give less fragmentation of the molecular ion than EI. All ofthe subsequent discussion of mass spectrometry is limited to positive-ion electron-impact mass spectrometry.

22

Chapter 4 Mass Spectrometry

could easily be distinguished by high resolution mass spectroscopy. In general, if the mass of any fragment in the mass spectrum can be accurately determined, there is usually only one combination of elements which can give rise to that signal since there are only a limited number of elements and their masses are accurately known. By examining a mass spectrum at sufficiently high resolution, one can obtain the exact composition of each ion in a mass spectrum, unambiguously. Most importantly, determining the accurate mass of [M]+- gives the molecular formula ofthe compound.

Table 4.1 Isotope

Accurate Masses of Selected Isotopes Natural

Mass

Abundance (%) lH

99.98

1.00783

12C

98.9

12.0000

BC

1.1

13.00336

14N

99.6

14.0031

160

99.8

15.9949

19F

100.0

18.99840

31p

100.0

30.97376

32 8

95.0

31.9721

338 34 8

0.75

32.9715

4.2

33.9679

35Cl

75.8

34.9689

37C1

24.2

36.9659

79Br

50.7

78.9183

81Br

49.3

80.9163

(2)

Isotope ratios. For some elements (most notably bromine and chlorine), there exists more than one isotope ofhigh natural abundance e.g. bromine has two abundant isotopes - 79Br 49 % and 81Br 51 %; chlorine also has two abundant isotopes- 37Cl

25 % and 35Cl 75% (Table 4.1). The presence ofBr or Cl or other elements that contain significant proportions (;::: 1%) of minor isotopes is often obvious simply by inspection of ions near the molecular ion. The relative intensities of the [M]+', [M+1]+' and [M+2]+' ions exhibit a characteristic pattern depending on the elements that make up the ion. For any molecular ion (or fragment) which contains one bromine atom, the mass spectrum will contain two

25

Chapter 4 Mass Spectrometry

peaks separated by two m/e units, one for the ions which contain 79Br and one for the ions which contain 81Br. For bromine-containing ions, the relative intensities of the two ions will be approximately the same since the natural abundances of79Br and 81Br are approximately equal. Similarly, for any molecule (or fragment of an molecule) which contains one chlorine atom, the mass spectrum will contain two fragments separated by two m/e units, one for the ions which contain 35Cl and one for the ions which contain 37Cl. For chlorine-containing ions, the relative intensities of the two ions will be approximately the 3: 1 since this reflects the natural abundances of 35Cl and 37Cl. Any molecular ion (or fragment) which contains 2 bromine atoms will have a pattern ofM:M+2:M+4 with signals in the ration 1:3:1 and any molecular ion (or fragment) which contains 2 chlorine atoms will have a pattern ofM:M+2:M+4 with signals in the ration 10:6:1. (3)

Molecular Fragmentation. The fragmentation pattern is a molecular

fingerprint. In addition to the molecular ion peak, the mass spectrum (see Figure 4.1) consists of a number of peaks at lower mass number and these result from fragmentation of the molecular ion. The principles determining the mode of fragmentation are reasonably well understood, and it is possible to derive structural information from the fragmentation pattern in several ways.

(a)

The appearance of prominent peaks at certain mass numbers can be correlated empirically with certain structural elements (Table 4.2), e.g. a prominent peak at

m/e = 43 is a strong indication of the presence of a CH 3-CO- group in the molecule. (b)

Information can also be obtained from differences between the masses of two peaks. Thus a prominent fragment ion that occurs 15 mass numbers below the molecular ion, suggests strongly the loss of a CH 3- group and therefore that a methyl group was present in the substance examined.

(c)

The knowledge of the principles governing the mode offragmentation of ions makes it possible to confirm the structure assigned to a compound and, quite often, to determine the juxtaposition of structural fragments and to distinguish between isomeric substances. For example, the mass spectrum of benzyl methyl ketone, Ph-CHz-CO-CH 3 contains a strong peak at m/e

= 91 due to the stable ion

Ph-CHz+, but this ion is absent in the mass spectrum of the isomeric propiophenone Ph-CO-CHzCH3 where the structural elements Ph- and -CH z- are separated. Instead, a prominent peak occurs at m/e = 105 due to the stable ion Ph-C=O+.

26

Chapter 4 Mass Spectrometry

Electronic databases of the mass spectral fragmentation patterns of known molecules can be rapidly searched by computer. The pattern and intensity of fragments in the mass spectrum is characteristic of an individual compound so comparison of the experimental mass spectrum of a compound with those in a library can be used to positively identify it, if its spectrum has been recorded previously.

Table 4.2

Common Fragments and their Masses Mass

Fragment

Fragment

Mass

Fragment

Mass

o II

NO

15

29

30

31

C-

29

-N~

46

0-

77

H"""

o II

43

HO"""

C-

55

OH /

CH2=C

"-

45

57

60

CsH s

65

OH

Q-CHZ-

C6H s

91

N3 N -

CH2-

92

C6H 6

C7 H7

CH30 C~ /; II

°

119

1-

o-~° C7HSO

105

127

CaH70

27

Chapter 4 Mass Spectrometry

It is now common to couple an instrument for separating a mixture of organic compounds e.g. using gas chromatography (GC) or high performance liquid chromatography (HPLC), directly to the input of a mass spectrometer. In this way, as each individual compound is separated from the mixture, its mass spectrum can be recorded and compared automatically with the library of known compounds and identified immediately if it is a known compound.

(4)

Meta-stable peaks in a mass spectrum arise if the fragmentation process a" ~ b" +

C

(neutral)

takes place within the ion-accelerating region of the mass spectrometer (Figure 4.1). Ion peaks corresponding to the masses of a" and to b" (m a and m b ) may be accompanied by a broader peak at mass m', such that:

z

mb

m*=

This often permits positive identification of a particular fragmentation path.

4.4

REPRESENTATION OF FRAGMENTATION PROCESSES

As fragmentation reactions in a mass spectrometer involve the breaking of bonds, they can be represented by the standard "arrow notation" used in organic chemistry. For some purposes a radical cation (e.g. a generalised ion of the molecular ion) can be represented without attempting to localise the missing electron: [M]+'

or

[H3C-CHz-O-R] +.

However, to show a fragmentation process it is generally necessary to indicate "from where the electron is missing" even though no information about this exists. In the case of the molecular ion corresponding to an alkyl ethyl ether, it can be reasonably inferred that the missing electron resided on the oxygen. The application of standard arrow notation permits us to represent a commonly observed process, viz. the loss of a methyl fragment from the [H3C-CHz-O-R] +. molecular ion:

28

Chapter 4 Mass Spectrometry

4.5

FACTORS GOVERNING FRAGMENTATION PROCESSES

Three factors dominate the fragmentation processes: (a)

Weak bonds tend to be broken most easily

(b)

Stable fragments (not only ions, but also the accompanying radicals and molecules) tend to be formed most readily

(c)

Some fragmentation processes depend on the ability of molecules to assume cyclic transition states.

Favourable fragmentation processes naturally occur more often and ions thus formed give rise to strong peaks in the mass spectrum.

4.6

EXAMPLES OF COMMON TYPES OF FRAGMENTATION

There are a number of common types of cleavage which are characteristic of various classes of organic compounds. These result in the loss of well-defined fragments which are characteristic of certain functional groups or structural elements. (1)

Cleavage at Branch Points. Cleavage of aliphatic carbon skeletons at branch

points is favoured as it leads to more substituted (and hence more stable) carbocations. The mass spectrum of 2,2-dimethylpentane shows strong peaks at m/e 85 and m/e

=

=

57 where cleavage leads to the formation of stable tertiary carbocations. CH3

--~.~

+·1

CH 3-C-CH2-CH2-CH3

I

CH3

m/e= 100

CH3

+1 neutral fragment

+.

CH 3 1

CH 3-C-CH2-CH2-CH3 --~.~

bH~

C-CH2-CH2-CH3 I CH 3 stable cation m/e= 85

CH 3

1+

CH3-C

I stable CH 3 cation m/e= 57

neutral fragment

29

Chapter 4 Mass Spectrometry

(2)

P- Cleavage.

~

Chain cleavage tends to occur

to heteroatoms, double bonds

and aromatic rings because relatively stable, delocalised carbocations result in each case.

(a)

•• I I -e R-X-C-C- ----+

I

I

~1~(L

R-X-C-CI I

X = 0, N, S, halogen

+ /

R-X-C

t +

.....-.

R-X=C

" " resonance stablised carbocation

(b)

, /

/

I , C-C-

C=C

/1

, C=C

I

/ ~

'+C-C / /

~

/

CI

resonance stablised carbocation

a '7 ::::,....

I C- C-

I

I

I

/

\

----+

neutral fragment

-

resonance stablised carbocation

30

'C\ neutral fragment

.C-

-8

I ~C, .....-.

+VJ

neutral fragment

-

I

\

\

- e'

/ '+-C-

(c)

.C/

/

Chapter 4 Mass Spectrometry

(3)

Cleavage a to carbonyl groups. Cleavage tends to occur a to carbonyl

groups to give stable acylium cations. R may be an alkyl, -OH or -OR group.

~. • O'

0 \I

C 'C/ 'R /

-e

ell

--. ~/C'R --.

\

/

\

+0 III C I R

/

'C\

neutral fragment

t resonance stablised carbocation

(4)

0 II C+ I R

Cleavage a to heteroatoms. Cleavage of chains may also occur a to

heteroatoms, e.g. in the case of ethers:

••

I

-e

R-O-C- -

I

+~

I

.

R-O-C- - + R-O:

CI

I free radical

(5)

+\

carbocation

retro Diels-Alder reaction. Cyclohexene derivatives may undergo a retro

Diels-Alder reaction:

31

Chapter 4 Mass Spectrometry

(6) The Mcl.afferty rearrangement. Compounds where the molecular ion can assume the appropriate 6-membered cyclic transition state usually undergo a cyclic fragmentation, known as the McLafferty rearrangement. This rearrangement involves a transfer of a y hydrogen atom to an oxygen and is often observed with ketones, acids and esters: (\ H Y / 10+ '(,.C_

. \.It"

+.......... H 10

+........... H :0

......--. I II I ----+ II C /C" • R/ ~C /c,,{\/W R C R C \ ~ 1\

0./\

/

c_ II c\

I \

/ c_

II

c\

With primary carboxylic acids, R-CH 2-COOH, this fragmentation leads to a characteristic peak at m/e

=

60

With carboxylic esters, two types of McLafferty rearrangements may be observed and ions resulting from either fragmentation pathway are observed in the mass spectrum: /

C_

II

c\

/

C_

II

c\

32

Chapter 5 NMR Spectroscopy

5 NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY

5.1 . (1)

THE PHYSICS OF NUCLEAR SPINS AND NMR INSTRUMENTS The Larmor Equation and Nuclear Magnetic Resonance

All nuclei have charge because they contain protons and some of them also behave as if they spin. A spinning charge generates a magnetic dipole and is associated with a small magnetic field H (Figure 5.1). Such nuclear magnetic dipoles are characterised by nuclear magnetic spin quantum numbers which are designated by the letter I and can take up values equal to 0, liz, 1,3/z ... etc.

H

d~ I Figure 5.1

A spinning positive charge generates a magnetic field and behaves like a small magnet

It is useful to consider three types of nuclei:

Type 1:

Nuclei with I = O. These nuclei do not interact with the applied magnetic field and are not NMR chromophores. Nuclei with I

=

0 have an even

number of protons and even number of neutrons and have no net spin. This means that nuclear spin is a property characteristic of certain isotopes rather than of certain elements. The most prominent examples of nuclei with I

=

0 are 12C and 160, the dominant isotopes of carbon and

oxygen. Both oxygen and carbon also have isotopes that can be observed by NMR spectroscopy.

33

Chapter 5 NMR Spectroscopy

Type 2:

Nuclei with 1 = I/Z' These nuclei have a non-zero magnetic moment and are NMR visible and have no nuclear electric quadrupole (Q). The two most important nuclei for NMR spectroscopy belong to this category: IH (ordinary hydrogen) and l3C (a non-radioactive isotope of carbon occurring to the extent of 1.06% at natural abundance). Also, two other commonly observed nuclei 19F and 31phave 1 = I/Z' Together, NMR data for IHand l3C account for well over 90% of all NMR observations in the literature and the discussion and examples in this book all refer to these two nuclei. However, the spectra of all nuclei with 1 = 1/Z can be understood easily on the basis of common theory.

Type 3:

Nuclei with 1 > I/Z' These nuclei have both a magnetic moment and an electric quadrupole. This group includes some common isotopes (e.g. zH and 14N) but they are more difficult to observe and spectra are generally very broad. This group of nuclei will not be discussed further.

The most important consequence of nuclear spin is that in a uniform magnetic field, a nucleus of spin 1 may assume 21 + I orientations. For nuclei with 1 = I/Z' there are just 2 permissible orientations (since 2 x I/Z + 1 = 2). These two orientations will be of unequal energy (by analogy with the parallel and antiparallel orientations of a bar magnet in a magnetic field) and it is possible to induce a spectroscopic transition (spin-flip) by the absorption of a quantum of electromagnetic energy

(~E)

of the

" appropriate frequency (v): V

= ~E h

(5.1)

In the case ofNMR, the energy required to induce the nuclear spin flip also depends on the strength of the applied field, H o ' It is found that (5.2) where K is a constant characteristic of the nucleus observed. Equation 5.2 is known as the Larmor equation and is the fundamental relationship in NMR spectroscopy. Unlike other forms of spectroscopy, in NMR the frequency of the absorbed electromagnetic radiation is not an absolute value for any particular transition, but has a different value depending on the strength of the applied magnetic field. For every value of H o ' there is a matching value of v corresponding to the condition of

resonance according to Equation 5.2, and this is the origin of the term Resonance in Nuclear Magnetic Resonance Spectroscopy. Thus for IH and 13C, resonance

34

.

~\

"

Chapter 5 NMR Spectroscopy

frequencies corresponding to magnitudes of applied magnetic field (Ho ) commonly found in commercial instruments are given in Table 5.1.

Table 5.1

Resonance Frequencies of IH and

l3 C

Nuclei in Magnetic Fields of

Different Strengths v IH (MHz)

v 13C (MHz)

u, (Tesla)

60

15.087

1.4093

90

22.629

2.1139

100

25.144

2.3488

200

50.288

4.6975

400

100.577

9.3950

500

125.720

11.744

600

150.864

14.0923

750

188.580

17.616

800

201.154

18.790

900

226.296

21.128

In common jargon, NMR spectrometers are commonly known by the frequency they use to observe 'H i.e. as "60 MHz", "200 MHz" or "400 MHz" instruments, even if the spectrometer is set to observe a nucleus other than 'H. All the frequencies listed in Table 5.1 correspond to the radio frequency region of the electromagnetic spectrum and inserting these values into Equation 5.1 gives the size of the energy gap between the states in an NMR experiment. A resonance frequency of 100 MHz corresponds to an energy gap of approximately 4 x 10-5 klmol'. This is an extremely small value on the chemical energy scale and this means that NMR spectroscopy is, for all practical purposes, a ground-state phenomenon. Any absorption signal observed in a spectroscopic experiment must originate from excess of the population in the lower energy state, the so called Boltzmann excess, which is equal to Np-Na , where N p and Na are the populations in the lower (p) and upper (u) energy states.

35

Chapter 5 NMR Spectroscopy

For molar quantities, the general Boltzmann relation (Equation 5.3) shows that: AE

N~

=e

RT

(5.3)

Clearly, as the energy gap (ilE) approaches zero, the right hand side of Equation 5.3 approaches I and the Boltzmann excess becomes very small. For the NMR experiment, the population excess in the lower energy state is typically of the order of I in 105 which renders NMR spectroscopy an inherently insensitive spectroscopic technique. Equations 5.1 and 5.2 show that the energy gap (and therefore ultimately the Boltzmann excess and sensitivity), increases with increasing applied magnetic field. This is one of the reasons why it is desirable to use high magnetic fields in NMR spectrometers.

(2)

N"clear Relaxation

Even at the highest fields, the NMR experiment would not be practicable if mechanisms did not exist to restore the Boltzmann equilibrium that is perturbed as the result of the absorption of electromagnetic radiation in making an NMR measurement. These mechanisms are known by the general term of relaxation and are not confined to NMR spectroscopy. Because of the small magnitude of the Boltzmann excess in the NMR experiment, relaxation is more critical and more important in NMR than in other forms of spectroscopy. If relaxation is too efficient (i.e. it takes a short time for the nuclear spins to relax after being excited in an NMR experiment) the lines observed in the NMR spectrum are very broad. Ifrelaxation is too slow (i.e. it takes a long time for the nuclear spins to relax after being excited in an NMR experiment) the spins in the sample quickly saturate and only a very weak signal can be observed. The most important relaxation processes in NMR involve interactions with other nuclear spins that are in the state of random thermal motion. This is called spinlattice relaxation and results in a simple exponential recovery process after the spins are disturbed in an NMR experiment. The exponential recovery is characterised by a time constant T, that can be measured for different types of nuclei. For organic liquids and samples in solution, T, is typically of the order of several seconds. In the presence of paramagnetic impurities or in very viscous solvents, relaxation of the spins can be very efficient and NMR spectra obtained become broad.

36

Chapter 5 NMR Spectroscopy

Nuclei in solid samples typically relax very efficiently and give rise to very broad spectra. NMR spectra of solid samples can only be acquired using specialised spectroscopic equipment and solid state NMR spectroscopy will not be discussed further.

(3)

The Acquisition ofan NMR spectrum

As the NMR phenomenon is not observable in the absence of an applied magnetic field, a magnet is an essential component of any NMR spectrometer. Magnets for NMR may be permanent magnets (as in many low field routine instruments), electromagnets, or in most modem instruments they are based on superconducting solenoids, cooled by liquid helium. All magnets used for NMR spectroscopy share . the following characteristics:

(a)

The magnetic field must be strong. This is partly due to the fact that the sensitivity of the NMR experiment increases as the strength of the magnet increases, but more importantly it ensures adequate dispersion of signals and, in the case of 'H NMR, also very important simplification of the spectrum.

(b)

The magnetic field must be extremely homogeneous so that all portions of the sample experience exactly the same magnetic field. Any inhomogeneity of the magnetic field will result in broadening and distortion of spectral bands. For determining of the structure of organic compounds, the highest attainable degree of magnetic field homogeneity is desirable, because useful information may be lost if the width of the NMR spectral lines exceeds about 0.2 Hz. Clearly, 0.2 Hz in, say, 100 MHz implies a homogeneity of about 2 parts in 109 , and this is a very stringent requirement over the whole volume of an NMR sample.

(c)

The magnetic field must be very stable, so that it does not drift during the acquisition of the spectrum, which may take from several seconds to several hours.

5.2

CONTINUOUS WAVE (CW) NMR SPECTROSCOPY

Inspection of the Larmor equation (Equation 5.2) shows that for any nucleus the condition of resonance may be achieved by keeping the field constant and changing (or sweeping) the frequency or, alternatively, by keeping the frequency constant and sweeping the field. A schematic diagram of a frequency sweep CW NMR spectrometer is given in Figure 5.2.

37

Chapter 5 NMR Spectroscopy

Rf.

transmitter

J-~~-----' ~

Frequency sweep

Figure 5.2

Magnet

~ integral

LJl

spectrum

x-axis magnetic field or frequency

Schematic Representation of a CW NMR Spectrometer

An NMR spectrum is effectively a graph of the intensity of absorption of Rf radiation (y-axis) against the frequency of the Rfradiation (x-axis). Since frequency and magnetic field strength are linked by the Larrnor equation, the x-axis could also be calibrated in units of magnetic field strength. In a CW NMR spectrometer, the x-axis of the output device (usually a pen plotter) is coupled to the frequency sweep so that the response of the sample is displayed as the frequency of the Rftransmitter varies. NMR spectroscopy is a quantitative technique and

'n NMR spectra are usually

recorded with an integral which indicates the relative areas of the absorption peaks in the spectrum. The area of a peak is proportional to the number of protons which give rise to the signal. In most NMR spectrometers, the integral is represented as a horizontal line plotted over the spectrum. Whenever a peak is encountered, the vertical displacement of the integral line is proportional to the area of the peak.

'n

NMR spectroscopy is an excellent tool for the analysis of mixtures - if a sample contains more than one compound then the areas of the signals belonging to each species in the NMR spectrum will reflect the relative concentrations of the species in the mixture.

38

Chapter 5 NMR Spectroscopy

5.3

FOURIER-TRANSFORM (FT) NMR SPECTROSCOPY

As an alternative to the CW method, an intense short pulse of electromagnetic energy can be used to excite the nuclei in an NMR sample. The first property of pulsed NMR spectroscopy is that all of the nuclei are excited simultaneously whereas the CW NMR experiment requires a significant period of time (usually several minutes) to sweep or scan through a range of frequencies. Following the radio frequency pulse, the magnetism in the sample is sampled as a function of time and, for a single resonance, the detected signal decays exponentially. The detected signal is called a free induction decay or FID (Figure 5.3a) and this type of spectrum (known as a timedomain spectrum) is converted into the more usual frequency-domain spectrum (Figure 5.3b) by performing a mathematical operation known as Fourier transformation (FT). Because the signal needs mathematical processing, pulsed NMR spectrometers require a computer and as well as performing the Fourier transformation, the computer also provides a convenient means of storing NMR data and performing secondary data processing and analysis.

(a)

(b)

FT

--.

time

Figure 5.3

--.

frequency --.

Time Domain and Frequency Domain NMR Spectra

Most NMR spectra consist of a number of signals and their time-domain spectra appear as a superposition of a number of traces of the type shown in Figure 5.3. Such spectra are quite uninterpretable by inspection, but Fourier transformation converts them into' ordinary frequency-domain spectra. The time-scale of the FID experiment is of the order of seconds during which the magnetisation may be sampled many thousands of time. Data sampling is accomplished by a dedicated computer that is also used to perform the Fourier transformation. The principal advantage ofFT NMR spectroscopy is a great increase in sensitivity per unit time of the experiment. A CW scan generally takes of the order of one hundred

39

Chapter 5 NMR Spectroscopy

times as long as the collection of the equivalent FID. During the time it would have taken to acquire one CW spectrum, the mini computer can accumulate many FID scans and add them up in its memory. The sensitivity (signal-to-noise ratio) of the NMR spectrum is proportional to the square root of the number of scans which are added together, so the quality ofNMR spectra is vastly improved as more scans are added. It is the increase in sensitivity brought about by the introduction of FT NMR spectroscopy that has permitted the routine observation of l3C NMR spectra. Although it s possible to acquire many spectra in rapid succession using pulsed NMR methods, one needs to be aware that the speed with which multiple FIDs can be acquired is still subject to the fact that the nuclei in the sample need to relax between acquisitions (Section 5.1). If successive FIDs are acquired too rapidly, intensity information will be distorted because those nuclei which relax slowly will not be fully relaxed when subsequent scans are acquired and they will contribute less to the resulting signal. To ensure that the signal intensities are accurate, the repetition rate needs to be such that even any slowly relaxing nuclei in the sample are fully relaxed between scans. In addition, the FID can be manipulated mathematically to enhance sensitivity (e.g. for routine l3C NMR) at the expense of resolution, or to enhance resolution

(often important for IH NMR) at the expense of sensitivity. Furthermore, it is possible to devise sequences of Rf pulses that result, after suitable mathematical manipulation, in NMR spectroscopic data that are of great value. Such methods (e.g. two-dimensional NMR, mathematical enhancement and massage of data) are, in ,

I

the most part, beyond the scope of this book however some aspects are discussed in Chapter 7.

5.4

CHEMICAL SHIFT IN 1H NMR SPECTROSCOPY

It is clear that NMR spectroscopy could be used to detect certain nuclei (e.g. IH, l3C,

19F, 31P) and, also to estimate them quantitatively. The real usefulness ofNMR

spectroscopy in chemistry is based on secondary phenomena, the chemical shift and spin-spin coupling and, to a lesser extent, on effects related to the time-scale of the

NMR experiment. Both the chemical shift and spin-spin coupling reflect the chemical environment of the nuclear spins whose spin-flips are observed in the NMR experiment and these can be considered as chemical effects in NMR spectroscopy.

40

Chapter 5 NMR Spectroscopy

A 'H NMR spectrum is a graph of resonance frequency (chemical shift) vs. the intensity ofRf absorption by the sample. The spectrum is usually calibrated in dimensionless units called "parts per million" (abbreviated to ppm) although the horizontal scale is a frequency scale, the units are converted to ppm so that the scale has the same numbers irrespective of the strength of the magnetic field in which the measurement was made. The scale in ppm, termed the 0 scale, is usually referenced to the resonance of some standard substance whose frequency is chosen as 0.0 ppm. The frequency difference between the resonance of a nucleus and the resonance of the reference compound is termed the chemical shift. Tetramethylsilane, (CH3)4Si, (abbreviated commonly as TMS) is the usual reference compound chosen for both 1Hand l3C NMR and it is normally added directly to the solution of the substance to be examined. TMS has the following advantages as a reference compound:

(a)

it is a relatively inert low boiling (b.p. 26.5°C) liquid which can be easily removed after use;

(b)

it gives a sharp single signal in both 'H and l3C because the compound has only one type of hydrogen and one type of carbon;

(c)

the chemical environment of both carbon and hydrogen in TMS is unusual due to the presence of silicon and hence the TMS signal occurs outside the normal range observed for organic compounds so the reference signal is unlikely to overlap a signal from the substance examined;

(d)

the chemical shift of TMS is not substantially affected by complexation or solvent effects because the molecule doesn't contain any polar groups.

Chemical shifts can be measured in Hz but are more usually expressed in ppm. chemical shift (0) in ppm

chemical shift from lMS in Hz

=

spectrometer frequency in MHz

Note that for a spectrometer operating at 200 MHz, 1 ppm corresponds to 200 Hz

i.e. for a spectrometer operating at x MHz, 1.00 ppm corresponds to exactly x Hz. For the majority of organic compounds, the chemical shift range for 'H covers approximately the range 0-10 ppm (from TMS) and for 13C covers approximately the range 0-220 ppm (from TMS). By convention, the 0 scale runs (with increasing values) from right-to-left; for 'H.

etc

9

.-

15 scale

8 I

7

6

5

4

3 I

2

o

-1

etc -+

I

ppm

41

Chapter 5 NMR Spectroscopy

Each IH nucleus is shielded or screened by the electrons that surround it. Consequently each nucleus feels the influence of the main magnetic field to a different extent, depending on the efficiency with which it is screened. Each IH nucleus with a different chemical environment has a slightly different shielding and hence a different chemical shift in the IH NMR spectrum. Conversely, the number of different signals in the IH NMR spectrum reflects the number of chemically distinct environments for IH in the molecule. Unless two IH environments are precisely identical (by symmetry) their chemical shifts must be different. When two nuclei have identical molecular environments and hence the same chemical shift, they are termed chemically equivalent or isochronous nuclei. Non-equivalent nuclei that fortuitously have chemical shifts that are so close that their signals are indistinguishable are termed accidentally equivalent nuclei. The chemical shift of a nucleus reflects the molecular structure and it can therefore be used to obtain structural information. Further, as hydrogen and carbon (and therefore IH and l3C nuclei) are universal constituents of organic compounds the amount of

structural information available from IH and l3C NMR spectroscopy greatly exceeds in value the information available from other forms of molecular spectroscopy. Every hydrogen and carbon atom in an organic molecule is "a chromophore" for NMR spectroscopy. For IH NMR, the intensity of the signal (which may be measured by electronically measuring the area under individual resonance signals) is directly proportional to the I

number of nuclei undergoing a spin-flip and proton NMR spectroscopy is a quantitative method. Any effect which alters the density or spatial distribution of electrons around a IH nucleus will alter the degree of shielding and hence its chemical shift. IH chemical shifts are sensitive to both the hybridisation of the atom to which the IH nucleus is attached (sp 2, sp' etc.) and to electronic effects (the presence of neighbouring electronegative/electropositive groups). Nuclei tend to be deshielded by groups which withdraw electron density. Deshielded nuclei resonate at higher 8 values (away from TMS). Conversely shielded nuclei resonate at lower 8 values (towards TMS). Low field end of spectrum Nuclei deshielded

010

42

High field end of spectrum Nuclei shielded

05

o0

ppm from TMS

Chapter 5 NMR Spectroscopy

Electron withdrawing substituents (-OH, -OCOR, -OR, -N0 2 , halogen) attached to an aliphatic carbon chain cause a downfield shift of 2-4 ppm when present at C u and have less than half of this effect when present at C 13. When sp2 hybridised carbon atoms (carbonyl groups, olefinic fragments, aromatic rings) are present in an aliphatic carbon chain they cause a downfield shift of 1-2 ppm when present at Cu' They have less than half of this effect when present at C 13'.

Tables 5.2 and 5.3 give characteristic shifts for IH nuclei in some representative organic compounds. Table 5.4 gives characteristic chemical shifts for protons in common alkyl derivatives. Table 5.5 gives characteristic chemical shifts for the olefinic protons in common substituted alkenes. To a first approximation, the shifts induced by substituents attached an alkene are additive. So, for example, an olefinic proton which is trans to a -CN group and has a geminal alkyl group will have a chemical shift of approximately 6.25 ppm [5.25 + 0.55(trans-CN) + 0.45(gem-alkyl)].

Table 5.2

TypicallH Chemical Shift Values in Selected Organic Compounds Compound

~PH

(ppm from TMS)

CH4

0.23

CH 3Cl

3.05

CH2C12

5.33

CHCl 3

7.27

CH 3CH3

0.86

CH2=CH2

5.25

benzene

7.26

CH 3CHO

2.20 (CH 3) , 9.80 (-CHO)

CH 3CH2CH2Cl

1.06 (CH 3) , 1.8l(-CH2 - ) , 3.47(-CH2-CI)

43

Chapter 5 NMR Spectroscopy

Typical ihl Chemical Shift Ranges in Organic Compounds

Table 5.3

Group"

6 lH (ppm from TMS)

Tetramethylsilane (CH3)4Si

o

Methyl groups attached to Sp3 hybridised carbon atoms

0.8 - 1.2

Methylene groups attached to Sp3 hybridised carbon atoms

1.0 - 1.5

Methine groups attached to Sp3 hybridised carbon atoms

1.2 - 1.8

Acetylenic protons

2-3.5

Olefinic protons

5-8

Aromatic and heterocyclic protons

6-9

Aldehydic protons

9 - 10

-OR protons in alcohols, phenols or carboxylic acids; -SR protons in thio1s; -NH protons in amines or amides do not have reliable chemical shift ranges (see page 49).

'a Chemical Shifts (6) for Protons in Common Alkyl Derivatives

Table 5.4

CH3-X

X

CH3

-CH3

-

CH2-

(CH3)2CH-X ---:- CH3

'CH-

-:

-H

0.23

0.86

0.86

0.91

1.33

-CH= CH2

1.71

1.00

2.00

1.00

1.73

-Ph

2.35

1.21

2.63

1.25

2.89

-CI

3.06

1.33

3.47

1.55

4.14

-Br

2.69

1.66

3.37

1.73

4.21

-I

2.16

1.88

3.16

1.89

4.24

-OH

3.39

1.18

3.59

1.16

3.94

-OCH3

3.24

1.15

3.37

1.08

3.55

-O-Ph

3.73

1.38

3.98

1.31

4.51

-OCO-CH3

3.67

1.21

4.05

1.22

4.94

-OCO-Ph

3.89

1.38

4.37

1.36

5.30

-CO- CH3

2.09

1.05

2.47

1.08

2.54

-CO-Ph

2.55

1.18

2.92

1.22

3.58

-CO-OCH3

2.01

1.12

2.28

1.15

2.48

-NH2

2.47

1.10

2.74

1.03

3.07

-NH-COCH3

2.71

1.12

3.21

1.13

4.01

-C=N

1.98

1.31

2.35

1.35

2.67

4.29

1.58

4.37

1.53

4.44

-

44

-

CH3CH2-X

N02

,

.'

Chapter 5 NMR Spectroscopy

Table 5.5

Approximate IH Chemical Shifts (0) for Olefinic Protons C=C-H / Xgem

Xtrans", OC=C-H

=5.25 +

CJgem

+ CJcis + CJtrans

C=C Xcis/

"H

X

CJgem

CJcis

CJtrans

-H

0.0

0.0

0.0

-alkyl

0.45

-0.22

-0.28

-aryl

1.38

0.36

-0.07

-CH=C~

1.00

-0.09

-0.23

1.24

0.02

-0.05

-C=C-H

0.47

0.38

0.12

-CO-R

1.10

1.12

0.87

-CO-OH

0.80

0.98

0.32

-CO-OR

0.78

1.01

0.46

-C=:N

0.27

0.75

0.55

-CI

1.08

0.18

0.13

-Br

1.07

0.45

0.55

-OR

1.22

-1.07

-1.21

-NRz

0.80

-1.26

-1.21

-CH=CH-conjugated

Table 5.6 gives characteristic IH chemical shifts for the aromatic protons in benzene derivatives. To a first approximation, the shifts induced by substituents are additive. So, for example, an aromatic proton which has a -N02 group in the para position and a -Br group in the ortho position will appear at approximately 7.82 ppm [(7.26 + 0.38(p-N02) + 0.18(o-Br)]. Tables 5.7 gives characteristic chemical shifts for IH nuclei in some polynuclear aromatic compounds and heteroaromatic compounds.

45

Chapter 5 NMR Spectroscopy

IH Chemical Shifts (0) for Aromatic Protons in Benzene

Table 5.6

Derivatives Ph-X in ppm Relative to Benzene at 0 7.26 ppm (positive sign denotes a downfield shift)

X

ortho

meta

para

-H

0.0

0.0

0.0

-CH3

-0.20

-0.12

-0.22

-C(CH 3h

-0.03

-0.08

0.20

-CH= CH2

0.06

-0.03

-0.10

-C=C-H

0.16

-0.04

-0.02

-CO-OR

0.71

0.11.

0.21

-CO-R

0.62

0.14

0.21

-OCO-R

-0.25

0.03

-0.13

-0.48

-0.09

-0.44

-OH

-0.56

-0.12

-0.45

-CI

0.03

-0.02

-0.09

-Br

0.18

-0.08

-0.04

-C:::N

0.36

0.18

0.28

-

N0 2

0.95

0.26

0.38

- NR2

-0.66

-0.18

-0.67

- NH2

-0.75

-0.25

-0.65

OCH3

-

IH Chemical Shifts (0) in some Polynuclear Aromatic Compounds

Table 5.7

and Heteroaromatic Compounds 7.71 7.81

"-': : "-': : "-': : CCO 8.31

7.46

~

o a

6.30 7.40

~

o S

7.91

~

7.04 7.19

Jh.8.12

7.39

lrU-~ II _~ 8.93

N

46

7.88

7.46

o

7.82

7.06 8.50

Chapter 5 NMR Spectroscopy

The chemical shift of a nucleus may also be affected by the presence in its vicinity of a magnetically anisotropic group (e.g. an aromatic ring or carbonyl group). In an aromatic ring, the "circulation" of electrons effectively forms a current loop which gives rise to an induced magnetic field. This is called the ring current effect and the induced field opposes the applied magnetic field of the spectrometer (B o) inside the loop and enhances the field outside the loop. The resonance of a nucleus which is located close to the face of an aromatic ring will be shifted to high field (towards TMS) because it experiences the effect of both the main spectrometer magnetic field but also the magnetic field from the ring current effect of the aromatic ring. Conversely a proton which is in the plane of an aromatic ring is deshielded by the ring current effect. shielding

induced electron circulation

........

(

deshielding

deshielding

_ ... ~.

Shielded

/ I

I

\

\

shielding

The ring current effect is the main reason that protons attached to aromatic rings typically appear at the low field end of the I H NMR spectrum since they are in the deshielded zone of the aromatic ring. There are also a number of common non-aromatic organic functional groups which are magnetically anisotropic and influence the magnetic field experienced by nearby nuclei. The greatest influence comes from multiple bonds and in particular, the C=C group, the C=N group, and C=C, N=O and C=O groups have strong magnetic anisotropies. Figure 5.4 depicts the shielding and de-shielding zones around common non-aromatic functional groups Shielding effects diminish with distance but are useful qualitative indicators of what groups are close by and also their geometric relationship in the three-dimensional structure of the molecule.

47

Chapter 5 NMR Spectroscopy

shielding I

-

shielding

deshielding

deshielding

\ I

I

\

\

shielding

Alkynes

Alkenes

, . I

r_ deshielding

deshielding ' { •

deshielding

deshielding

I

-I

-J \ I

I

\

\

shielding

Carbonyl groups Figure 5.4

Nitro groups

Shielding/deshielding Zones for Common Non-aromatic Functional Groups

Solvents for NMR Spectroscopy. NMR spectra are almost invariably obtained in solution. The solvents of choice: (a)

should have adequate dissolving power.

(b)

should not associate strongly with solute molecules as this is likely to produce appreciable effects on chemical shifts. This requirement must sometimes be sacrificed to achieve adequate solubility.

(c)

should be essentially free of interfering signals. Thus for IH NMR, the best solvents are proton-free.

(d)

should preferably contain deuterium, 2H. Deuterium is an isotope of hydrogen which is relatively easy to obtain and incorporate into common solvents in place of hydrogen with insignificant changes to the properties of the solvent. Almost all NMR instruments use deuterium as a convenient "locking" signal for to stabilise the magnetic field of the NMR magnet.

48

Chapter 5 NMR Spectroscopy

The most commonly used organic solvent is deuterochloroform, CDCI 3, which is an excellent solvent and is only weakly associated with most organic substrates. CDCl 3 contains no protons and has a deuterium atom. For ionic compounds or hydrophilic compounds, the most common solvent is deuterated water, DzO. Almost all deuterated solvents are not 100% deuterated and they contain a residual protonated impurity. With the sensitivity of modern NMR instruments, the signal from residual protons in the deuterated solvent is usually visible in the IH NMR spectrum. For many spectra, the signal from residual protons can be used as a reference signal (instead of adding TMS) since the chemical shifts of most common solvents are known accurately. In CDCb, the residual CRCb has a shift of7.27 ppm in the IH NMR spectrum. Solvents that are miscible with water (and are difficult to . "dry" completely) e.g. CD 3COCD3, CD 3SOCD3, DzO, also commonly contain a small amount of residual water. The residual water typically appears as a broad resonance in the region 3 - 5 ppm in the IH NMR spectrum.

Labile and Exchangeable protons. Protons in groups such as alcohols (R-OH) amines (R-NH-), carboxylic acids (RCOOH), thiols (R-SH) and to a lesser extent amides (R-CO-NH-) are classified as labile or readily exchangeable protons. Labile protons frequently give rise to broadened resonances in the lH NMR spectrum and their chemical shifts are critically dependent on the solvent, concentration, and on temperature and they do not have reliable characteristic chemical shift ranges. Labile protons exchange rapidly with each other and also with protons in water or with the deuterons in DzO.

R-O-D + H-O-D Labile protons can always be positively identified by in situ exchange with DzO. In practice, a normal IH NMR spectrum is recorded then deuterium exchange of labile protons is achieved by simply adding a drop of deuterated water (DzO) to the NMR sample. Labile protons in -OH, -COOH, -NH z and -SH groups exchange rapidly for deuterons in DzO and the IH NMR is recorded again. Since deuterium is invisible in the IH NMR spectrum, labile protons disappear from the IH NMR spectrum and can be readily identified by comparison of the spectra before and after DzO is addition. The N-H protons of primary and secondary amides are slow to exchange and require heating or base catalysis and this is one wayan amide functional group can be distinguished from other functional groups.

49

Chapter 5 NMR Spectroscopy

5.5

SPIN-SPIN COUPLING IN 1H NMR SPECTROSCOPY

A typical organic molecule contains more than one magnetic nucleus (e.g. more than one IH, or IH and

31p

etc.). When one nucleus can sense the presence of other nuclei

through the bonds ofthe molecule the signals will exhibit fine structure (splitting or

multiplicity). Multiplicity arises because if an observed nucleus can sense the presence of other nuclei with magnetic moments, those nuclei could be in either the a. or J3 state. The observed nucleus is either slightly stabilised or slightly destabilised by depending on which state the remote nuclei are in, and as a consequence nuclei which sense coupled partners with an a. state have a slightly different energy to those which sense coupled partners with a J3 state. The additional fine structure caused by spin-spin coupling is not only the principal cause of difficulty in interpreting 'H NMR spectra, but also provides valuable structural information when correctly interpreted. The coupling constant (related to the size of the splittings in the multiplet) is given the symbol J and is measured in Hz. By convention, a superscript before the symbol'J' represents the number of intervening bonds between the coupled nuclei. Labels identifying the coupled nuclei are usually indicated as subscripts after the symbol'J' e.g. 2Jab = 2.7 Hz would indicate a coupling of2.7 Hz between nuclei a and b which are separated by two intervening bonds. Because J depends only on the number, type and spatial arrangement of the bonds separating the two nuclei, it is a property of the molecule and is independent of the applied magnetic field. The magnitude of 1, or even the mere presence of detectable interaction, constitutes valuable structural information. Two important observations that relate to IH - 'H spin-spin coupling:

(a)

No inter-molecular spin-spin coupling is observed. Spin-spin coupling is transmitted through the bonds of a molecule and doesn't occur between nuclei in different molecules.

(b)

The effect of coupling falls off as the number of bonds between the coupled nuclei increases. 'H - lH coupling is generally unobservable across more than 3 intervening bonds. Unexpectedly large couplings across many bonds may occur if there is a particularly favourable bonding pathway e.g. extended It-conjugation or a particularly favourable rigid a-bonding skeleton (Table 5.8).

50

Chapter 5 NMR Spectroscopy

Table 5.8

Typical ifl - IH Coupling Constants

Group

J(Hz)

-16

CH 3CHzCHzCH 3

ZJHH:::::

CH 3CHzCHzCH 3

3JHH

CH 3CHzCHzCH3

4JHH = 0.3

HzC=C=C=CH z

5JHH = 7

HzC=CH-CH=CH z

5JHH = 1.3

= 7.2

4JHH = 1.5

Signal Multiplicity - the n+l rule. Spin-spin coupling gives rise to multiplet splittings in IH NMR spectra. The NMR signal of a nucleus coupled to n equivalent hydrogens will be split into a multiplet with (n+l) lines. For simple multiplets, the spacing between the lines (in Hz) is the coupling constant. The relative intensity of the lines in multiplet will be given by the binomial coefficients of order In' (Table 5.9).

Table 5.9

Relative Line Intensities for Simple Multiplets

multiplicity

n

n+l

relative line

multiplet

intensities

name

0

1

1

singlet

1

2

1:1

doublet

2

3

1:2 : 1

triplet

3

4

1:3 :3 : 1

quartet

4

5

1:4:6:4:1

quintet

5

6

1 : 5 : 10: 10: 5 : 1

sextet

6

7

1 : 6 : 15 : 20 : 15 : 6 : 1

septet

7

8

1 : 7 : 21 : 35 : 35 : 21 : 7 : 1

octet

8

9

1 : 8 : 28 : 56 : 70 : 56 : 28 : 8 : 1

nonet

51

,r .1

Chapter 5 NMR Spectroscopy

These simple multiplet patterns give rise to characteristic "fingerprints" for common fragments of organic structures. A methyl group, -CH 3, (isolated from coupling to other protons in the molecule) will always occur as a singlet. A CH 3-CHz- group, (isolated from coupling to other protons in the molecule) will appear as a quartet (-CH z-) and a triplet (CHd. Table 5.10 shows the schematic appearance of the NMR

spectra of various common molecular fragments encountered in organic molecules.

Table 5.10

Characteristic Multiplet Patterns for Common Organic Fragments

-CH2-

-CH3

quartet

triplet

area = 2

area = 3

- CH2-CH3

an ethyl

gro"~ 1 : 3: 3: 1

1:2 : 1

-, /CH-

-CH3

quartet

doublet

area = 1

area = 3

1 :3:3:1

1:1

-CH2-

X-CH,-CH,-Y

-C H2-

triplet

triplet

area = 2

area = 2

~ 1:2:1

-CH

/ CH3

1 : 2: 1

doublet area = 6

-CHseptet

' CH3 an isopropyl group

area

=1

~ 1: 6 : 15: 20: 15: 6: 1

52

1: 1

Chapter 5 NMR Spectroscopy

5.6

ANALYSIS OF 1H NMR SPECTRA

To obtain structurally useful information from NMR spectra, one must solve two separate problems. Firstly, one must analyse the spectrum to obtain the NMR parameters (chemical shifts and coupling constants) for all the protons and, secondly, one must interpret the values of the coupling constants in tenns of established relationships between these parameters and structure. (1)

A spin system is defined as a group of coupled protons. Clearly, a spin system

cannot extend beyond the bounds of a molecule, but it may not include a whole molecule. For example, isopropyl propionate comprises two separate and isolated proton spin systems, a seven-proton system for the isopropyl residue and a five-proton . system for the propionate residue, because the ester group effectively provides a barrier (5 bonds) against coupling between the two parts.

CH3

'"

CH

i

3

i

7-spin system:

(2)

,

CH-+O-C+CH2CH3 / : II:

0

Isopropyl propionate

i

: 5-spin system

Strongly and weakly coupled spins. These terms refer not to the actual

magnitude of J, but to the ratio of the separation of chemical shifts expressed in Hz (Av) to the coupling constant Jbetween them. For most purposes, if LlvlJ is larger than -3, the spin system is termed weakly coupled. When this ratio is smaller than -3, the spins are termed strongly coupled. Two important conclusions follow:

(a)

Because the chemical shift separation (Av) is expressed in Hz, rather than in the dimensionless (5 units, its value will change with the operating frequency of the spectrometer, while the value of J remains constant. It follows that two spins will become progressively more weakly coupled as the spectrometer frequency increases. Weakly coupled spin systems are much more easy to analyse than strongly coupled spin systems and thus spectrometers operating at higher frequencies (and therefore at higher applied magnetic fields) will yield spectra which are more easily interpreted. This has been an important reason for the development ofNMR spectrometers operating at ever higher magnetic fields.

53

Chapter 5 NMR Spectroscopy

(b)

Within a spin system, some pairs of nuclei or groups of nuclei may be strongly coupled and others weakly coupled. Thus a spin-system may be partially

strongly coupled.

(3)

Magnetic equivalence. A group of protons is magnetically equivalent when

they not only have the same chemical shift (chemical equivalence) but also have identical spin-spin coupling to each individual nucleus outside the group.

(4)

Conventions used in naming spin systems. Consecutive letters of the

alphabet (e.g. A, B, C D, .....) are used to describe groups of protons which are strongly coupled. Subscripts are used to give the number of protons that are magnetically equivalent. Primes are used to denote protons that are chemically equivalent but not magnetically equivalent. A break in the alphabet indicates weakly coupled groups. For example: ABC denotes a strongly coupled 3-spin system AMX denotes a weakly coupled 3-spin system ABX denotes a partially strongly coupled 3-spin system A3BMXY denotes a spin system in which the three magnetically equivalent A nuclei are strongly coupled to the B nucleus, but weakly coupled to the M, X and Y nuclei. The nucleus X is strongly coupled to the nucleus Y but weakly coupled to all the other nuclei. The nucleus M is weakly coupled to all the other 6 nuclei. AA'XX' is a 4-spin system described by two chemical shift parameters (for the nuclei A and X) but where J AX "F J AX" A and A' (as well as X and X') are pairs of nuclei which are chemically equivalent but magnetically non-equivalent. The process of deriving the NMR parameters (8 and 1) from a set of multiplets in a spin system is known as the analysis ofthe NMR spectrum. In principle, any spectrum arising from a spin system, however complicated, can be analysed but some

will require calculations or simulations performed by a computer. Fortunately, in a very large number of cases, multiplets can be correctly analysed by inspection and direct measurements. These spectra are known as first order spectra and they arise from weakly coupled spin systems. At high applied magnetic fields, a large proportion of IH NMR spectra are nearly pure first-order and there is a tendency for simple molecules, e.g. those exemplified in the problems in this text, to exhibit first-order spectra even at moderate fields.

54

Chapter 5 NMR Spectroscopy

5.7

Rule 1

RULES FOR SPECTRAL ANALYSIS OF FIRST ORDER SPECTRA

A group of n magnetically equivalent protons will split a resonance of an interacting group of protons into n+ I lines. For example, the resonance due to the A protons in an AnXm system will be split into m+ I lines, while the resonance due to the X protons will be split into n+1 lines. More generally, splitting by n nuclei of spin quantum number I, results in 2nI+ I lines. This simply reduces to n+ I for protons where I = Yz.

Rule 2

The spacing (measured in Hz) of the lines in the multiplet will be equal to the coupling constant. In the above example all spacings in both parts of the spectrum will be equal to JAX'

Rule 3

The true chemical shift of each group of interacting protons lies in the centre of the (always symmetrical) multiplet.

Rule 4

The relative intensities of the lines within each multiplet will be in the ratio of the binomial coefficients (Table 5.9). Note that, in the case of higher multiplets, the outside components of multiplets are relatively weak and may be lost in the instrumental noise, e.g. a septet may appear as a quintet if the outer lines are not clearly visible. The intensity relationship is the first to be significantly distorted in non-ideal cases, but this does not lead to serious errors in spectral analysis.

RuleS

When a group of magnetically equivalent protons interacts with more than one group of protons, its resonance will take the form of a multiplet of multiplets. For example, the resonance due to the A protons in a system AnM~m

will have the multiplicity of (p+ I )(m+ I). The multiplet patterns

are chained e.g. a proton coupled to 2 different protons will be split to a doublet by coupling to the first proton then each of the component of the doublet will be split further by coupling to the second proton resulting in a symmetrical multiplet with 4 lines (a doublet of doublets).

HM I

HA

I

Hx I

X-C-C-C-y

I I I

doublet of doublets

55

Chapter 5 NMR Spectroscopy

HM H1A Hx I

I

I

I I

X-C-C-C-y HM

triplet of doublets or

doublet of triplets

The appropriate coupling constants will control splitting and relative intensities will obey rule 4. Rule 6

Protons that are magnetically equivalent do not split each other. Any system An will give rise to a singlet.

Rule 7

Spin systems that contain groups of chemically equivalent protons that are not magnetically equivalent cannot be analysed by first-order methods.

Rule 8

If !1VAB/JAB is less than -3, for any pair of nuclei A and B in the spin system, the spectra become distorted from the expected ideal multiplet patterns and the spectra cannot be analysed by first-order methods.

56

Chapter 5 NMR Spectroscopy

(1) Splitting Diagrams The knowledge of the rules listed above, pennits the development of a simple procedure for the analysis of any spectrum which is suspected of being first order. The first step consists of drawing a splitting diagram, from which the line spacings can be measured and identical (hence related) splittings can be identified (Figure 5.5).

)

3.5

Figure 5.5

2.5

3.0 8 (ppm from TMS)

A Portion of the IH NMR Spectrum of Styrene Epoxide (100 MHz as a 5% solution in CCI4)

The section of the spectrum of styrene epoxide (Figure 5.5) clearly contains the signals from 3 separate protons (identified as HI, Hz and H 3) with HI at 8 2.95, Hz at 8 2.58 and H3 at 8 3.67 ppm. Each signal appears as a doublet of doublets and the chemical shift of each proton is simply obtained by locating the centre of the multiplet. The pair of nuclei giving rise to each splitting is clearly indicated by the splitting diagram above each multiplet with 3JHZ_H3

=:

2JH I_HZ =:

5.9 Hz,

3JHI_H3

=:

4.0 Hz and

2.5 Hz.

The validity of a first order analysis can be verified by calculating the ratio !1vlJ for each pair of nuclei and establishing that it is greater than 3.

57

Chapter 5 NMR Spectroscopy

From Figure 5.5 =

37

72

=

= 6.3

5.9

=

= 18.0

4.0

109 2.5

= 43.6

Each ratio is greater than 3 so a first order analysis is justified and the 100 MHz spectrum of the aliphatic protons of styrene oxide is indeed a first order spectrum and could be labelled as an AMX spin system. The 60 MHz IH spectrum of a 4 spin AMX 2 system is given in Figure 5.6. This system contains 3 separate proton signals (in the intensity ratios 1:1:2, identified as HA> HM and Hx)' The multiplicity of H; is a triplet of doublets, the multiplicity ofHM is a triplet of doublets and the multiplicity ofHx is a doublet of doublets. Again, the nuclei giving rise to each splitting are clearly indicated by the splitting diagram above each multiplet and the chemical shifts of each multiplet are simply obtained by measuring the centres of each multiplet.

HM

HA

/) =7.0 ppm

HX

0= 6.0 ppm v = 360 Hz

v = 420 Hz t>V

AM

= 60 Hz

__------_____

t>V

MX

=63 Hz

0= 4.95 ppm v = 297 Hz

...E . ---------_ / J AX = 6.0 Hz / J MX = 3.5 Hz

/ J

AX

/ J

=6.0 Hz

'IH

'IH

400

350

I

Figure 5.6

58

= 3.5 Hz

/ JAM = 1.5 Hz

/J AM=1.5HZ

7.0

MX

2H

300

I 6.0

5.0

(Hz from TMS)

o (ppm from TMS)

The 60 MHz IH NMR Spectrum of a 4-Spin AMX 2 Spin System

Chapter 5 NMR Spectroscopy

A spin system comprising just two protons (i.e. an AX or an AB system) is always exceptionally easy to analyse because, independent ofthe value of the ratio of !1v/J, the spectrum always consists ofjust four lines with each pair of lines separated by the coupling constant J. The only distortion from the first-order pattern consists of the gradual reduction of intensities of the outer lines in favour of the inner lines, a characteristic "sloping" or "tenting" towards the coupling partner. A series of simulated spectra of two-spin systems are shown in Figure 5.7. v

V1

J12

2

6v

-,

-J

"

12

= 10.0

12

-

100

Figure 5.7

50

o Hz

-50

-100

Simulated IH NMR Spectra of a 2-Spin System as the Ratio txvl J, is Varied from 10.0 to 0.0

59

Chapter 5 NMR Spectroscopy

(2) Spin Decoupling

In the signal of a proton that is a multiplet due to spin-spin coupling, it is possible to remove the splitting effects by irradiating the sample with an additional Rf source at the exact resonance frequency of the proton giving rise to the splitting. The additional radiofrequency causes rapid flipping of the irradiated nuclei and as a consequence nuclei coupled to them cannot sense them as being in either an a or

~

state for long

enough to cause splitting. The irradiated nuclei are said to be decoupled from other nuclei in the spin system. Decoupling simplifies the appearance of complex multiplets by removing some of the splittings. In addition, decoupling is a powerful tool for assigning spectra because the skilled spectroscopist can use a series of decoupling experiments to sequentially identify which nuclei are coupled. In a 4-spin AM 2X spin system, the signal for proton HA would appear as a doublet of triplets (with the triplet splitting due to coupling to the 2 M protons and the doublet splitting due to coupling to the X proton). Irradiation at the frequency ofHx reduces the multiplicity of the A signal to a triplet (with the remaining splitting due to JAM) and irradiation at the frequency ofHM reduces the multiplicity of the A signal to a doublet (with the remaining splitting due to J AX) (Figure 5.8).

HM I

HA

I

Hx I

X-C-C-C-y I I I H M

Basic spectrum of HA without irradiation of of H M or H x

Figure 5.8

60

with irradiation of H x

with irradiation ofH M

Selective Decoupling in a Simple 4-Spin System

Chapter 5 NMR Spectroscopy

(3)

Correlation of1H _lH Coupling Constants with Structure

Interproton spin-spin coupling constants are of obvious, value in obtaining structural data about a molecule, in particular information about the connectivity of structural elements and the relative disposition of various protons.

Non-aromatic Spin Systems. In saturated systems, the magnitude of the geminal coupling constant 2JH_C_H (two protons attached to the same carbon atom) is typically between 10 and 16 Hz but values between 0 and 22 Hz have been recorded in some unusual structures.

2

JAB

=10 -16 Hz.

The vicinal coupling (protons on adjacent carbon atoms)

3JH_C_C_H

can have values

o- 16 Hz depending mainly on the dihedral angle . HA HB I

I

-C-C-

I I 3 'JAB

= 0 -16 Hz.

The so-called Karplus relationship expresses approximately, the angular dependence of the vicinal coupling constant as: 3JH_C_C_H

= 10 cos?

for 0 < < 90° and

3JH_C_C_H

= 15 cos-

for 90 < < 180°



It follows from these equations that if the dihedral angle



between two vicinal

protons is near 90° then the coupling constant will be very small and conversely, if the dihedral angle



between two vicinal protons is near 0° or 180° then the coupling

constant will be relatively large. The Karplus relationship is of great value in determining the stereochemistry of organic molecules but must be treated with caution because vicinal coupling constants also depend markedly on the nature of substituents. In systems that assume an average conformation, such as a flexible hydrocarbon chain, 3J H _H generally lies between 6 and 8 Hz.

61

Chapter 5 NMR Spectroscopy

The coupling constants in unsaturated (olefmic) systems depend on the nature of the substituents attached to the C=C but for the vast majority of substituents, the ranges for 3JH _C=C_H(ciS) and 3JH_ C=C_H(lrans) do not overlap. This means that the stereochemistry of the double bond can be determined by measuring the coupling constant between vinylic protons. Where the C=C bond is in a ring, the 3JH_C=C_H coupling reflects the ring size.

3

= 5 -7 Hz

= 6 - 11 Hz

JAB(CiS)

3 JAC(trans)

= 12 - 19 Hz

2

=a- 3 Hz

JBC(gem)

= 9 - 11 Hz

The magnitude of the long-range allylic coupling, (41AB) is controlled by the dihedral angle between the C-H A bond and the plane of the double bond in a relationship reminiscent of the Karplus relation.

'" / HA

/

x

C

Hs C=C

/

/

"-

He

/Aromatic Spin Systems In aromatic systems, the coupling constant between protons attached to an aromatic ring is characteristic of the relative position ofthe coupled protons i.e. whether they are ortho, meta or para.

3 'JAB(orthO)

=6 - 10Hz

4 JAB(meta)

= 1 - 3 Hz

5 'JAB(para)

=a- 1.5 Hz

Similarly in condensed polynuclear aromatic compounds and heterocyclic compounds, the magnitude of the coupling constants between protons in the aromatic rings reflects the relative position of the coupled protons.

62

Chapter 5 NMR Spectroscopy

4

50

,-,:::: 2

00 I ~ ~ 5

3

6:-....

N

4

=8.3 -

9.1 Hz

3J2.3

3 2 ,3

= 6.1 - 6.9 Hz

3 J 3 ,4

4J 1,3

= 1.2 -1.6 Hz

4

3J1 ,2

J

=4.0 =6.8 -

I

3 2

=0.0 - 2.5 Hz

= 0 -1.0 Hz

4 J 3 ,S

= 0.5 - 1.8 Hz

sJ1,s=0-1.5Hz

4J2.6

= 0.0 - 0.6 Hz

sJ2 S

=0.0 -

3J 2 ,3

3J2,3

9.1 Hz

J2,4

SJ1•4

=4.7 Hz 3J 3 ,4 =3.4 Hz J2,4 =1.0 Hz 4 J2.S =2.9 Hz

5.7 Hz

=1.8 Hz

=3.5 Hz J2,4 =0.8 Hz

3 J 3 ,4

4

4

4 J2,S =

1.6 Hz

2.3 Hz

The splitting patterns of the protons in the aromatic region of the IH spectrum are frequently used to establish the substitution pattern of an aromatic ring. For example, a trisubstituted aromatic ring has 3 remaining protons. There are 3 possible arrangements for the 3 protons - they can have relative positions 1,2,3-; 1,2,4-; or 1,3,5- and each has a characteristic splitting pattern. HB

HA

Hc

n n M "':q"' JAJ1L ill n JAJJL n ~ "'*z JuL z*x ~ ~ M 3

3

X

4

J BC(Of1hO)

JAC(meta)

Z

Hc

HB

HA

HB

3

JAC(para)

~

4

JAB(meta)

y

HC

HB

4

4

JAC(meta)

I

JAC(para)

JBC(meta)

Hc

HA

~

5

4

y

Hc

JBC(meta)

JAB(orthO)

5

HA

4

3

JAB(OrlhO)

~I

JAC(meta)

j}JJL

y

X

JBC(orthO)

3

4

~I

3

JAB(orthO)

J AB(Of1hO)

JAB(meta)

4

JBC(meta)

HB

JJIl

JJl

4

JAC(meta)

4

JBC(meta)

~

63

Chapter 5 NMR Spectroscopy

para-Disubstituted benzenes para-Disubstituted benzenes have characteristically "simple" and symmetrical lH

NMR spectra in the aromatic region. Superficially, the spectra of p-disubstituted benzenes always appear as two strong doublets with the line positions symmetrically disposed about a central frequency. The spectra are in fact far more complex (many lines make up the pattern for the NMR spectrum when it is analysed in detail) but the symmetry of the pattern of lines makes 1,4-disubstituted benzenes very easy to recognise from their lH NMR spectra. The lH NMR spectrum of p-nitrophenylacetylene is given in Figure 5.9. The expanded section shows the 4 strong prominent signals in the aromatic region, characteristic of 1,4-substitution on a benzene ring.

H-C=C-Q-N02

expansion

8 Figure 5.9

7

I

i

8.25

7.75

6

5

i

ppm

ppm from TMS

IH NMR Spectrum of p-Nitrophenylacetylene (200 MHz as a 10% solution in CDCh)

>";

64

Chapter 6

13 C

NMR Spectroscopy

6 13C

NMR SPECTROSCOPY

The most abundant isotope of carbon (l2C) cannot be observed by NMR. 13C is a rare nucleus (1.1 % natural abundance) and its low concentration coupled with the fact that 13C has a relatively low resonance frequency, leads to its relative insensitivity as an NMR-active nucleus (about 116000 as sensitive as 'H). However, with the increasing availability of routine pulsed FT NMR spectrometers, it is now common to acquire many spectra and add them together (Section 5.3), so l3C NMR spectra of good quality can be obtained readily.

6.1

COUPLING AND DECOUPLING IN 13C NMR SPECTRA

Because the 13C nucleus is isotopically rare, it is extremely unlikely that any two adjacent carbon atoms in a molecule will both be 13c. As a consequence, BC_BC coupling is not observed in 13C NMR spectra i.e. there is no signal multiplicity or splitting in a 13C NMR spectrum due 13C_13C coupling. 13C couples strongly to any protons that may be attached (IJCH is typically about 125 Hz for saturated carbon atoms in organic molecules). It is the usual practice to irradiate the 'H nuclei during l3C acquisition so that all ll-l are fully decoupled from the 13C nuclei (usually termed broad band decoupling or noise decoupling). BC NMR spectra usually appear as a series of singlets (when 'H is fully decoupled) and each distinct

l3e environment in

the molecule gives rise to a separate signal. If IH is not decoupled from the 13C nuclei during acquisition, the signals in the 13C spectrum appear as multiplets where the major splittings are due to the

lJC_H

couplings

(about 125 Hz for Sp3 hybridised carbon atoms, about 160 Hz for Sp2 hybridised carbon atoms, about 250 Hz for sp hybridised carbon atoms). CH 3- signals appear as quartets, -CH z- signals appear as triplets, -CH- groups appear as doublets and quaternary C (no attached H) appear as singlets. The multiplicity information, taken together with chemical shift data, is useful in identifying and assigning the 13C resonances.

65

Chapter 6

13C

NMR Spectroscopy

In BC spectra acquired without proton decoupling, there is usually much more "long

range" coupling information visible in the fine structure of each multiplet. The fine structure arises from coupling between the carbon and protons that are not directly bonded to it (e.g. from

2JC_C_H' 3JC_C_C_H).

The magnitude oflong range C-H coupling

is typically < 10 Hz and this is much less than

IJC_H•

Sometimes a more detailed

analysis of the long-range C-H couplings can be used to provide additional information about the structure of the molecule. In most BC spectra, BC nuclei which have directly attached protons receive a significant (but not easily predictable) signal enhancement when the protons are decoupled as a result of the Nuclear Overhauser Effect (see Section 7.3) and as a consequence, peak intensity does not necessarily reflect the number of BC nuclei giving rise to the signal. It is not usually possible to integrate routine 13C spectra directly unless specific

precautions have been taken. However with proper controls, BC NMR spectroscopy can be used quantitatively and it is a valuable technique for the analysis of mixtures. To record 13C NMR spectra where the relative signal intensity can be reliably determined, the spectra must be recorded with techniques to suppress the Nuclear Overhauser Effect and with a long delay between the acquisition of successive spectra to ensure that all of the carbons in the molecule are completely relaxed between spectral acquisitions.

, SFORD : Off- resonance decoupling. Another method for obtaining BC NMR spectra (still retaining the multiplicity information) involves the application of a strong decoupling signal at a single frequency just outside the range of proton resonances. This has the effect of incompletely or partially decoupling protons from the 13C nuclei. The technique is usually referred to as offresonance decoupling or SFORD (Single Frequency Off Resonance Decoupling). When a SFORD spectrum is acquired, the effect on the BC spectrum is to reduce the values of splittings due to all carbon-proton coupling (Figure 6.1d). The multiplicity due to the larger one-bond CH couplings remains, making it possible to distinguish by inspection whether a carbon atom is a part of a methyl group (quartet), methylene group (triplet), a methine (CH) group (doublet) or a quaternary carbon (a singlet) just as in the fully proton-coupled spectrum. It should be noted that because the protons are partially decoupled, the magnitude of the splittings observed in the signals in a SFORD BC NMR spectrum is not the C-H coupling constant (the splittings are always less than the real coupling constants). SFORD spectra are useful only to establish signal multiplicity.

66

Chapter 6

6.2

13C

NMR Spectroscopy

DETERMINING 13C SIGNAL MULTIPLICITY USING DEPT

With most modem NMR instrumentation, the DEPT experiment (Distortionless Enhancement by Polarisation Transfer) is the most commonly used method to determine the multiplicity of BC signals. The DEPT experiment is a pulsed NMR experiment which requires a series of programmed Rfpulses to both the 'H and BC nuclei in a sample. The resulting BC DEPT spectrum contains only signals arising from protonated carbons (non protonated carbons do not give signals in the BC DEPT spectrum). The signals arising from carbons in CH 3 and CH groups (i.e. those with an odd number of attached protons) appear oppositely phased from those in CH 2 groups (i.e. those with an even number of attached protons) so signals from CH 3 and CH . groups point upwards while signals from CH 2 groups point downwards (Figure 6.1b). In more advanced applications, the BC DEPT experiment can be used to separate the signals arising from carbons in CH 3 , CH 2 and CH groups. This is termed spectral editing and can be used to produce separate I3C sub-spectra ofjust the CH 3 carbons, just the CH 2 carbons or just the CH carbons. Figure 6.1 shows various I3C spectra of methyl cyc1opropyl ketone. The BC spectrum acquired with full proton decoupling (Figure 6.la) shows 4 singlet peaks, one for each of the 4 different carbon environments in the molecule. The DEPT spectrum (Figure 6.1b) shows only the 3 resonances for the protonated carbons. The carbon atoms that have an odd number of attached hydrogens (CH and CH 3 groups) point upwards and those with an even number of attached hydrogen atoms (the signals of CH2 groups) point downwards. Note that the carbonyl carbon does not appear in the DEPT spectrum since it has no attached protons. In the carbon spectrum with no proton decoupling (Figure 6.lc), all of the resonances of protonated carbons appear as multiplets and the multiplet structure is due to coupling to the attached protons. The CH 3 (methyl) group appears as a quartet, the CH 2 (methylene) groups appear as a triplet and the CH (methine) group appears as a doublet while the carbonyl carbon (with no attached protons) appears as a singlet. In Figure 6.1c, all of the

IJC_H

coupling constants could be measured directly from the

spectrum. The SFORD spectrum (Figure 6.1d) shows the expected multiplicity for all of the resonances but the multiplets are narrower due to partial decoupling of the protons and the splittings are less than the true values of IJC_H'

67

Chapter 6 13C NMR Spectroscopy

(d) with 1 HOff-Resonance Decoupled (SFORD)

___..1. ...

'W

r

-CH

(c) with 1 H fully coupled

I

:;C=Q

I

J

(a) with 1 H fully decoupled

I

I

215

205

Figure 6.1

13C

30

20

10

ppm

NMR Spectra of Methyl Cyclopropyl Ketone (CDCh

Solvent, 100 MHz). (a) Spectrum with Full Broad Band Decoupling of IH ; (b) DEPT Spectrum (c) Spectrum with no Decoupling of IH; (d) SFORD Spectrum

68

Chapter 6

13 C

NMR Spectroscopy

For purposes of assigning a I3C spectrum, two I3C spectra are usually obtained. Firstly, a spectrum with complete 1H decoupling to maximise the intensity of signals and provide sharp singlets signals to minimise any signal overlap. This is the best spectrum to count the number of resonances and accurately determine their chemical shifts. Secondly, a spectrum which is sensitive to the number of protons attached to each C to permit partial sorting of the BC signals according to whether they are methyl, methylene, methine or quaternary carbon atoms. This could be a DEPT spectrum, a I3C spectrum with no proton decoupling or a SFORD spectrum. The number of resonances visible in a I3C NMR spectrum immediately indicates the

number of distinct BC environments in the molecule (Table 6.1). If the number of l3C environments is less than the number of carbons in the molecule, then the

. molecule must have some symmetry that dictates that some BC nuclei are in identical environments. This is particularly useful in establishing the substitution pattern (position where substituents are attached) in aromatic compounds.

The Number of Aromatic I3C Resonances in Benzenes with

Table 6.1

Different Substitution Patterns

Molecule

0 o-CI

ceCl ~

Number of aromatic I3C resonances

Molecule

Number of aromatic I3C resonances

1

CI-Q-CI

2

4

Br-Q-CI

4

CI

3

CI

Q Os,

6

Br

CI

CI

Q

4

6

CI

69

Chapter 6 13C NMR Spectroscopy

6.3

SHIELDING AND CHARACTERISTIC CHEMICAL SHIFTS IN 13C NMR SPECTRA

The general trends of BC chemical shifts somewhat parallel those in IH NMR spectra. However, BC nuclei have access to a greater variety of hybridisation states (bonding geometries and electron distributions) than IH nuclei and both hybridisation and changes in electron density have a significantly larger effect on BC nuclei than 1H nuclei. As a consequence, the BC chemical shift scale spans some 250 ppm, cf the 10 ppm range commonly encountered for IH chemical shifts (Tables 6.2 and 6.3).

Table 6.2

Typical 13C Chemical Shift Values in Selected Organic Compounds Compound

() 13{:

(ppm from TMS) CH 4 CH 3CH3 CH 30H CH 3CI CHCl3

-2.1 7.3 50.2 25.6 52.9 77.3

CH 3CHzCHzCI

11.5 (CH 3 )

cn.ci,

26.5 (-CHz-) 46.7 (-CHz-CI)

CHz=CH z

123.3

CHz=C=CH z

208.5 (=C=)

73.9 (=CHz) 31.2 (-CH 3 ) 200.5 (-CHO) 20.6 (-CH 3) , 178.1 (-COOH) 30.7 (-CH 3) , 206.7 (-CO-)

o

128.5 149.8 (C-2) 123.7 (C-3) 135.9 (C4)

70

Chapter 6 13C NMR Spectroscopy

Table 6.3

Typical 13C Chemical Shift Ranges in Organic Compounds

Group

BC shift (ppm)

TMS

0.0

-CH 3 (with only -H or -R at Cn and C~)

0-30

-CH z (with only -H or -R at Cn and C~)

20 - 45

C~)

30 - 60

-CH (with only -H or -R at Cn and

C quaternary (with only -H or -R at Cn and

C~)

30 - 50

O-CH 3

50 - 60

N-CH 3

15 - 45

C=C

70 - 95

C=C

105 - 145

C (aromatic)

110-155

C (heteroaromatic)

105 - 165

-C=N

115 - 125

C=O (acids, acyl halides, esters, amides)

155 - 185

C=O (aldehydes, ketones)

185 - 225

In BC NMR spectroscopy the BC signal due to the carbon in CDC13 appears as a triplet centred at 8 77.3 with peaks intensities in the ratio 1:1:1 (due to spin-spin coupling between BC and ZH). This resonance serves as a convenient reference for the chemical shifts of BC NMR spectra recorded in this solvent. Table 6.4 gives characteristic BC chemical shifts for some sp3-hybridised carbon atoms in common functional groups. Table 6.5 gives characteristic B C chemical shifts for some sp2-hybridised carbon atoms in substituted alkenes and Table 6.6 gives characteristic B C chemical shifts for some sp-hybridised carbon atoms in alkynes.

71

Chapter 6 13C NMR Spectroscopy

13C Chemical Shifts (0) for

Table 6.4

CH3-X X

-

CH3

sl Carbons in Alkyl Derivatives CH3CHz-X

-

-CHz-

CH3

(CH3hCH-X -CH3

CH-

/'

-H

-2.3

7.3

7.3

15.4

15.9

-CH=C~

18.7

13.4

27.4

22.1

32.3

-Ph

21.4

15.8

29.1

24.0

34.3

-CI

25.6

18.9

39.9

27.3

53.7

-OH

50.2

18.2

57.8

25.3

64.0

60.9

14.7

67.7

21.4

72.6

-OCO- CH3

51.5

14.4

60.4

21.9

67.5

-CO-CH3

30.7

7.0

35.2

18.2

41.6

-CO-O CH3

20.6

9.2

27.2

19.1

34.1

-NHz

28.3

19.0

36.9

26.5

43.0

-NH-CO CH3

26.1

14.6

34.1

22.3

40.5

-C=:N

1.7

10.6

10.8

19.9

19.8

-NOz

61.2

12.3

70.8

20.8

78.8

-

OCH3

Table 6.5

13C Chemical Shifts (0) for

Sp2

Carbons in Vinyl

Derivatives: CH2=CH-X X

72

<,

CH z=

=CH-X

-H

123.3

123.3

-CH3

115.9

136.2

-C(CH 3h

108.9

149.8

-Ph

112.3

135.8

-CH=C~

116.3

136.9

-C=C-H

129.2

117.3

-CO- CH3

128.0

137.1

-CO-OCH3

130.3

129.6

-CI

117.2

126.1

-OCH 3

84.4

152.7

-OCO-CH 3

96.6

141.7

-C=:N

137.5

108.2

-NO z

122.4

145.6

-N(CHJ)2

91.3

151.3

Chapter 6

Table 6.6

l3 C

13 C

NMR Spectroscopy

Chemical Shifts (0) for sp Carbons in Alkynes:

X-C=:C-Y

X

y

x-c-

=c-y

H-

-H

73.2

73.2

66.9

79.2

H-

-

CH3

H-

-C(CH 3 h

67.0

~2.3

H-

-CH=C~

80.0

82.8

H-

-C=C-H

66.3

67.3

H-

-Ph

77.1

83.4

H-

- COC H3

81.8

78.1

H-

-OCH 2CH3

22.0

88.2

CH 3 -

-CH 3

72.6

72.6

CH 3 -

-Ph

79.7

85.8

CH 3 -

-COCH 3

97.4

87.0

Ph-

-Ph

89.4

89.4

-COOCH 3

-COOCH 3

74.6

74.6

Table 6.7 gives characteristic

l3

e chemical shifts for the aromatic carbons in benzene

derivatives. To a first approximation, the shifts induced by substituents are additive. So, for example, an aromatic carbon which has a -NOz group in the para position and a -Br group in the ortho position will appear at approximately 137.9 ppm [(128.5 + 6.1(P-NO z) + 3.3(o-Br)].

73

Chapter 6 13C NMR Spectroscopy

Approximate 13C Chemical Shifts (0) for Aromatic Carbons in

Table 6.7

Benzene Derivatives Ph-X in ppm relative to Benzene at

o128.5 ppm (a positive sign denotes a downfield shift) X

ipso

ortho

meta

para

-H

0.0

0.0

0.0

0.0

-N02

19.9

-4.9

0.9

6.1

-CO-OCH 3

2.0

1.2

-0.1

4.3

-CO-NH 2

5.0

-1.2

0.1

3.4

-CO- CH3

8.9

0.1

-0.1

4.4

-C:=N

-16.0

3.5

. 0.7

4.3

-Br

-5.4

3.3

2.2

-1.0

-CH= CH2

8.9

-2.3

-0.1

-0.8

-CI

5.3

0.4

1.4

-1.9

9.2

0.7

-0.1

-3.0

-OCO-CH3

22.4

-7.1

0.4

-3.2

-OCH3

33.5

-14.4

1.0

-7.7

18.2

-13.4

0.8

-10.0

CH3

-

NH2

-

Tables 6.8 gives characteristic shifts for l3C nuclei in some polynuclear aromatic compounds and heteroaromatic compounds. Characteristic IJC Chemical Shifts (0) in some Polynuclear

Table 6.8

Aromatic Compounds and Heteroaromatic Compounds

.

128.0

CO I ~

132.5 125.9

~

133.6J

00

0::0 ~

§

132.2 109.9 143.0

130.1

J

Q

§

126.4 124.9

125.6

f

~

~

;J

-J 12~

130.0

.

132.3

' 28

0

.s

126.7

126.7

135.9

N

74

r.

00 127.3_

123.7 149.8

7 MISCELLANEOUS TOPICS

This section deals briefly with a number of more advanced topics in NMR spectroscopy, which indicate of the power ofNMR spectroscopy in solving complex structural problems.

7.1

DYNAMIC NMR SPECTROSCOPY: THE NMR TIME-SCALE

Two magnetic nuclei situated in different molecular environments must give rise to separate signals in the NMR spectrum, say tJ.v Hz apart (Figure 7.1a). However, if some process interchanges the environments of the two nuclei at a rate (k) much faster than tJ.v times per second, the two nuclei will be observed as a single signal at an intermediate frequency (Figures 7.ld and 7.le). When the rates (k) of the exchange process are comparable to tJ.v, exchange broadened spectra (Figure 7.lb) are observed. From the exchange broadened spectra, the rate constants for the exchange process (and hence the activation parameters tJ.G"', tJ.H"', tJ.S"') can be derived. Where signals coalesce (Figure 7.1c) from being two separate signals to a single averaged signal, the rate constant for the exchange can be approximated as k = rc.Av /

Fast exchange

t Q)

Cl

"'2.

e

c

III

s:

-... ..'>: ~ U X

Q)

0

d

.S:! III

C

Coalescence

Cl

c "iii III

~

b

o

.s a

Figure7.1

11

Slow exchange

1-- ~v--I

Schematic NMR Spectra of Two Exchanging Nuclei

75

Chapter 7 Miscellaneous Topics

In practice, a compound where an exchange process operates can give rise to a series of spectra of the type shown in Figure 7.1, if the NMR spectra are recorded at different temperatures. Changing the sample temperature alters the rate constant for the exchange (increasing the temperature increases the rate of an exchange process) and the spectra will have a different appearance depending on whether the rate constant, k (expressed in sec-') is large or small compared to the chemical shift differences between exchanging nuclei (flv expressed in Hz). Molecules where there

are exchange processes taking place may also give rise to different NMR spectra in different NMR spectrometers because flv depends on the strength of the magnetic field. An NMR spectrum which shows exchange broadening will tend to give a slow exchange spectrum if the spectrum is re-run in a spectrometer with a stronger magnetic field. The averaging effects of exchange apply to any dynamic process that takes place in a molecule (or between molecules). However, many processes occur at rates that are too fast or too slow to give rise to visible broadening ofNMR spectra. The NMR time-scale happens to coincide with the rates of a number of common chemical processes that give rise to variation of the appearance ofNMR spectra with temperature and these include:

(1)

Conformational exchange processes. Conformational processes can give rise

to exchange broadening in NMR spectra when a molecule exchanges between two or more conformations. Fortunately most conformational processes are so fast on the NMR time-scale that normally only averaged spectra are observed. In particular, in molecules which are not unusually sterically bulky, the rotation about C-C single bonds is normally fast on the NMR time scale so, for example, the 3 hydrogen atoms of a methyl group appear as a singlet as a result of averaging of the various rotational conformers. In molecules where there are very bulky groups, steric hindrance can slow the rotation about single bonds and give rise to broadening in NMR spectra. In molecules containing rings, the exchange between various ring conformations (e.g. chair-boatchair) can exchange nuclei. For example, cyclohexane gives a single averaged resonance in the 1H NMR at room temperature, but separate signals are seen for the axial and equatorial hydrogens when spectra are acquired at very low temperature.

76

Chapter 7 Miscellaneous Topics

(2) Intermolecular interchange oflabile (slightly acidic) protons. Functional groups such as -OH, -COOH, -NH 2 and -SH have labile protons which exchange with each other in solution. The -OH protons of a mixture of two different alcohols may give rise to either an averaged signal or to separate signals depending on the rate of exchange and this depends on many factors including temperature, the polarity of the solvent, the concentrations of the solutes and the presence of acidic or basic catalysts.

R-OH + R'-OH'

.......

R-OH' + R'-OH

(3) Rotation about partial double bonds. Exchange broadening is frequently observed in amides due to restricted rotation about the N-C bond of the amide

R I \

Hb

\

I

C-N

C-N II

o

group.

R

Ha

\

II

\

o

Hb

Ha

The restricted rotation about amide bonds often occurs at a rate that gives rise to observable broadening in NMR spectra. The restricted rotation in amide bonds

R \

results from the partial double bond

C-N

II

character of the C-N bond.

7.2

o

R

Hb

\

I

~

\

Hb C=N+

I

Ha

-0

I

\

Ha

THE EFFECT OF CHIRALITY

In an achiral solvent, enantiomers will give identical NMR spectra. However in a chiral solvent or in the presence of a chiral additive to the NMR solvent, enantiomers will have different spectra and this is frequently used to establish the enantiomeric purity of compounds. The resonances of one enantiomer can be integrated against the resonances of the other to quantify the enantiomeric purity ofa compound. In molecules that contain a stereogenic centre, the NMR spectra can sometimes be more complex than would otherwise be expected. Groups such as -CH 2- groups (or any -CX 2- group such as -e(Me)2- or -CR2-) require particular attention in molecules which contain a stereo genic centre. The carbon atom of a -CX2- group is termed a prochiral carbon if there is a stereogenic centre (a chiral centre) elsewhere in the

77

Chapter 7 Miscellaneous Topics

molecule. A prochiral carbon atom is a carbon in a molecule that would be chiral if one of its substituents was replaced by a different substituent. From an NMR perspective, the important fact is that the presence of stereogenic centre makes the substituents on a prochiral carbon atom chemically non-equivalent. So whereas the protons of a -CH 2- group in an acyclic aliphatic compound would normally be expected to be equivalent and resonate at the same frequency in the IH NMR spectrum, if there is a stereogenic centre in the molecule, each of the protons of the -CH 2- group will appear at different chemical shifts. Also, since they are nonequivalent, the protons will couple to each other typically with a large coupling of about 15 Hz. The effect of chirality is particularly important in the spectra of natural products including amino acids, proteins or peptides. Many molecules derived from natural sources contain a stereo genic centre and they are typically obtained as a single pure enantiomer. In these molecules, the resonances for all of the methylene groups

(i.e. -CH2- groups) in the molecule will be complicated by the fact that the two protons of the methylene groups will be non-equivalent. Figure 7.2 shows the aliphatic protons in the IH NMR spectrum of the amino acid cysteine (HSCH2CHNHtCOO} Cysteine has a stereogenic centre and the signals of the methylene group appear as separate signals at cS 3.18 and cS 2.92 ppm. Each of the methylene protons is split into a doublet of doublets due to coupling firstly to the other methylene proton and secondly to the proton on the a-carbon (He).

.' Ha i

COO-

Hb~'=-C-C--NH

+

1\3 SH He

3.5

Figure 7.2

3.0

ppm ex TMS

IH NMR Spectrum of the Aliphatic Region of Cysteine Indicating Non-equivalence of the Methylene Protons due to the Influence of the Stereogenic Centre

78

Chapter 7 Miscellaneous Topics

7.3

THE NUCLEAR OVERHAUSER EFFECT (NOE)

Irradiation of one nucleus while observing the resonance of another may result in a change in the amplitude of the observed resonance i.e. an enhancement of the signal intensity. This is known as the nuclear Overhauser effect (NOE). The NOE is a "through space" effect and its magnitude is inversely proportional to the sixth power of the distance between the interacting nuclei. Because of the distance dependence of the NOE, it is an important method for establishing which groups are close together in space and because the NOE can be measured quite accurately it is a very powerful means for determining the three dimensional structure (and stereochemistry) of organic compounds. The intensity of l3C resonances may be increased by up to 200% when IH nuclei which are directly bonded to the carbon atom are irradiated. This effect is very important in increasing the intensity of l3C spectra when they are proton-decoupled. The efficiency of the proton/carbon NOE varies from carbon to carbon and this is a factor that contributes to the generally non-quantitative nature of l3C NMR. While the intensity ofprotonated carbon atoms can be increased significantly by NOE, nonprotonated carbons (quaternary carbon atoms) receive little NOE and are usually the weakest signals in a l3C NMR spectrum.

79

_. Chapter 7 Miscellaneous Topics

7.4

TWO-DIMENSIONAL NMR SPECTROSCOPY

Since the advent of pulsed NMR spectroscopy, a number of advanced twodimensional techniques have been devised. These methods afford valuable information for the solution of complex structural problems. The technical detail behind multi-dimensional NMR is beyond the scope of this book.

Two-dimensional spectra have the appearance of surfaces, generally with .two axes corresponding to chemical shift and the third (vertical) axis corresponding to signal intensity.

It is usually more useful to plot twodimensional spectra viewed directly from above (a contour plot of the surface) in order to make measurements and assignments.

Chemical shift (F2)

The most important two-dimensional NMR experiments for solving structural problems are COSY (COrrelation Spect:r;oscopY), NOESY iliuc1ear Overhauser Enhancement ~pectroscopY), HSC (Heteronuclear ~hift ~orrelation) and TOCSY (TOtal Correlation SpectroscopY). Most modem high-field NMR spectrometers have the capability to routinely and automatically acquire COSY, NOESY, HSC and TOCSY spectra.

80

Chapter 7 Miscellaneous Topics

The COSY spectrum shows which pairs of protons in a molecule are coupled to each other. The COSY spectrum is a symmetrical spectrum that has the IH NMR spectrum of the substance as both of the chemical shift axes (F 1 and F2) . A schematic representation of COSY spectrum is given below. It is usual to plot a normal (one-dimensional) NMR spectrum along each of the axes

to give reference spectra for the peaks that appear in the two-dimensional spectrum. F2 axis

1HNMR _ Spectnrn

HC The COSY spectrum has a diagonal . set of peaks (open circles) as well as peaks that are off the diagonal (filled circles). The off-diagonal peaks are the important signals since these occur at positions where there is coupling between a proton on the F1 axis and one on the F2 axis. In the schematic spectrum on the right, the off-diagonal signals show that there is spin-spin coupling between He and Ho and also between HB and He but the proton labelled HA has no coupling partners.

Ho

·····j·····_j····_·r>~<:/

i·t··.>+~:·t· :

....

....

/

J~~1=~~t~~r:.:

1HNMR Spectnrn

In a single COSY spectrum, all of the spin-spin coupling pathways in a molecule can be identified.

The NOESY spectrum relies on the Nuclear Overhauser Effect and shows which pairs of nuclei in a molecule are close together in space. The NOESY spectrum is very similar in appearance to a COSY spectrum. It is a symmetrical spectrum that has the IH NMR spectrum of the substance as both of the chemical shift axes (F 1 and F2) . A schematic representation ofNOESY spectrum is given below. Again, it is usual to plot a normal (one-dimensional) NMR spectrum along each of the axes to give reference spectra for the peaks that appear in the two-dimensional spectrum. From the analysis of a NOESY spectrum, it is possible to determine the three dimensional structure of a molecule or parts of a molecule. The NOESY spectrum is particularly useful for establishing the stereochemistry (e.g. the cis/trans configuration of a double bond or a ring junction) of a molecule where more than one possible stereoisomer exists.

Chapter 7 Miscellaneous Topics

F2 axis

1HNMR _ Spectrun

The NOESY spectrum has a diagonal set of peaks (open circles) as well as peaks which are off the diagonal (filled circles). The offdiagonal peaks occur at positions where a proton on the F1 axis is close in space to a one on the F2 axis. In the schematic spectrum on the right, the off-diagonal signals show that HA must be located near Ho and He must be located near He.

1HNMR Spectrun

The HSC spectrum is the heteronuclear analogue of the COSY spectrum and identifies which protons are coupled to which carbons in the molecule. The HSC spectrum has the

IH

NMR spectrum of the substance on one axis (F2) and the

13C

spectrum (or the spectrum of some other nucleus) on the second axis (F I)' A schematic representation of an HSC spectrum is given below. It is usual to plot a normal (one-dimensional) I H NMR spectrum along the proton dimension and a normal (one-dimensional)

13C

NMR spectrum along the

13C

dimension to give

reference spectra for the peaks that appear in the two-dimensional spectrum.

F2 axis

1HNMR_ Spectrum

He

The HSC spectrum does not have diagonal peaks. The peaks in an HSC spectrum occur at positions where a proton in the spectrum on the F2 axis is coupled to a carbon in the spectrum on the on the F1 axis. In the schematic spectrum on the right, both HA and He are coupled to Cz, He is coupled to C y and Ho is coupled to CX.

82

HD

F1 axis

Cx Cy Cz

r

13CNMR Spectnrn

;"

Chapter 7 Miscellaneous Topics

In an HSC spectrum, the correlation between the protons in the 1H NMR spectrum and the carbon nuclei in the l3C spectrum can be obtained. It is usually possible to assign all of the resonances in the IH NMR spectrum i.e. establish which proton in a molecule gives rise to each signal in the spectrum, using spin-spin coupling information. The l3C spectrum can then be assigned by correlation to the proton resonances. The TOCSY spectrum is useful in identifying all of the protons which belong to an isolated spin system. Like the COSY and NOESY spectra, the TOCSY also has peaks along a diagonal at the frequencies of all of the resonances in the spectrum. The experiment relies on spin-spin coupling but rather than showing pairs of nuclei which are directly coupled together, the TOCSY shows a cross peak (off-diagonal peak) for every nucleus which is part of the spin system not just those that are directly coupled. The TOCSY spectrum is symmetrical about the diagonal and has the IH NMR spectrum of the substance as both of the chemical shift axes (F 1 and F2). A schematic representation ofTOCSY spectrum is given below. Again, it is usual to plot a normal (one-dimensional) NMR spectrum along each of the axes to give reference spectra for the peaks that appear in the two-dimensional spectrum.

F2 axis

HA1

The TOCSY spectrum has a diagonal set of peaks (open circles) as well as peaks which are off the diagonal (filled circles). The offdiagonal peaks occur at positions where a proton on the F1 axis is in the same spin system as one on the F2 axis. In the schematic spectrum on the right, there are two superimposed isolated 3-spin systems (HA 1 , HA2 , HA3 ) and (H X 1 , HX2 • HX3 ) and the cross peaks clearly indicate which resonances belong to each spin system.

II

1HNMR Spectrum

--

HA2 HX1 HX2 HX3

lL1lLill

HA3

II

<>++1 r,"

:.:: ::: ..0:::·

.

./

.::?::::::::::6:::::::6::::h:£<:::::.::::::::?::::::::::::: ·····; ····..·6··..··0<6···; )· · · ·

;~/~;~
r 1HNMR Spectrum

83

Chapter 7 Miscellaneous Topics

7.5

THE NMR SPECTRA OF "OTHER NUCLEI"

'H and l3C NMR spectroscopy accounts for the overwhelming proportion of all NMR observations. However, there are many other isotopes which are NMR observable and they include the common isotopes

19F, 31p

and 2H. The NMR spectroscopy of

these "other nuclei" has had surprisingly little impact on the solution of structural problems in organic chemistry and will not be discussed here. It is however important to be alert for the presence of other magnetic nuclei in the molecule, because they often cause additional multiplicity in 'H and l3C NMR spectra due to spin-spin coupling.

7.6

SOLVENT INDUCED SHIFTS

Generally solvents chosen for NMR spectroscopy do not associate with the solute. However, solvents which are capable of both association and inducing differential chemical shifts in the solute are sometimes deliberately used to remove accidental chemical equivalence. The most useful solvents for the purpose of inducing solvent-

shifts are aromatic solvents, in particular hexadeuterobenzene (C6D6) , and the effect is called aromatic solvent induced shift (ASIS). The numerical values of ASIS are usually of the order of 0.1 - 0.5 ppm and they vary with the molecule studied depending mainly on the geometry of the complexation.

84

Chapter 7 Miscellaneous Topics

8 DETERMINING THE STRUCTURE OF ORGANIC COMPOUNDS FROM SPECTRA The main purpose of this book is to present a collection of suitable problems to 'teach and train researchers in the general important methods of spectroscopy. Problems I - 277 are all of the basic "structures from spectra" type, are generally . relatively simple and are arranged roughly in order of increasing complexity. No solutions to the problems are given. It is important to assign NMR spectra as completely as possible and rationalise all numbered peaks in the mass spectrum and account for all significant features of the UV and IR spectra. The next group of problems (278-283) present data in text form rather than graphically. The formal style that is found in the presentation of spectral data in these problems is typical of that found in the experimental of a publication or thesis. This is a completely different type of data presentation and one that students will encounter frequently. Problems 284 - 291 involve the quantitative analysis of mixtures using IH and

I3 C

NMR. These problems demonstrate the power ofNMR in analysing samples

that are not pure compounds and also develop skills in using spectral integration. Problems 292 - 309 are a graded series of exercises in two-dimensional NMR (COSY, NOESY, C-H Correlation and TOCSY) ranging from very simple examples to demonstrate each of the techniques to complex examples where a combination of 2D methods is used to establish structure and distinguish between stereoisomers. Problem 310 deals with molecular symmetry and is a useful exercise to establish how symmetry in a molecule can be established from the number of resonances in IH and I3 C

NMR spectra. The last group of problems (311-332) are of a different type and

deal with interpretation of simple IH NMR spin-spin multiplets. To the best of our knowledge, problems of this type are not available in other collections and they are included here because we have found that the interpretation of multiplicity in IH NMR spectra is the greatest single cause of confusion in the minds of students. The spectra presented in the problems were obtained under conditions stated on the individual problem sheets. Mass spectra were obtained on an AEI MS-9 spectrometer or a Hewlett Packard MS-Engine mass spectrometer. 60 MHz IH NMR spectra and

85

Chapter 8 Determining the Structure of Organic Compounds from Spectra

15 MHz l3C NMR spectra were obtained on a Jeol FX60Q spectrometer, 20 MHz l3C NMR spectra were obtained on a Varian CFT-20 spectrometer, 100 MHz IH NMR spectra were obtained on a Varian XL-lOO spectrometer, 200 MHz IH NMR spectra and 50 MHz l3C NMR spectra were obtained on a Bruker AC-200 spectrometer, 400 MHz IH NMR spectra and 100 MHz l3CNMR spectra were obtained on Bruker AMX-400 or DRX-400 spectrometers, and 500 and 600 MHz IH NMR spectra were obtained on a Bruker DRX-500 or AMX-600 or DRX-600 spectrometers. Ultraviolet spectra were recorded on a Perkin-Elmer 402 UV spectrophotometer or Hitachi 150-20 UV spectrophotometer and Infrared spectra on a Perkin-Elmer 7 lOB or a Perkin-Elmer 1600 series FTIR spectrometer. The following collections are useful sources of spectroscopic data on organic compounds and some of the data for literature compounds have been derived from these collections: (a)

http://riodbOl.ibase.aist.go.jp/sdbs/cgi-bin/creindex.cgi?lang=eng website maintained by the National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan;

(b)

http://webbook.nist.gov/chemistry/ website which is the NIST Chemistry WebBook, NIST Standard Reference Database Number 69, June 2005, Eds. PJ. Linstrom and W.G. Mallard.

(c)

E Pretch, P Btihlmann and C Affolter, "Structure Determination of Organic Compounds, Tables of Spectral Data", 3rd edition, Springer, Berlin 2000.

While there is no doubt in our minds that the only way to acquire expertise in obtaining "organic structures from spectra" is to practise, some students have found the following general approach to solving structural problems by a combination of spectroscopic methods helpful: (1)

Perform all routine operations: (a)

Determine the molecular weight from the Mass Spectrum.

(b)

Determine relative numbers of protons in different environments from the 1H NMR spectrum.

(c)

Determine the number of carbons in different environments and the number of quaternary carbons, methine carbons, methylene carbons and methyl carbons from the l3C NMR spectrum.

86

Chapter 8 Determining the Structure of Organic Compounds from Spectra

(d)

Examine the problem for any additional data concerning composition and determine the molecular formula if possible. From the molecular formula, determine the degree of unsaturation.

(e) (2)

Determine the molar absorbance in the UV spectrum, if applicable.

Examine each spectrum (JR, mass spectrum, UV, l3C NMR, 'H NMR) in turn for obvious structural elements: (a)

Examine the IR spectrum for the presence or absence of groups with diagnostic absorption bands e.g. carbonyl groups, hydroxyl groups, NH groups, C=C or C=N, etc.

(b)

Examine the mass spectrum for typical fragments e.g. PhCHz-, CH 3CO-, CH 3- , etc.

(c)

Examine the UV spectrum for evidence of conjugation, aromatic rings etc.

(d)

Examine the lH NMR spectrum for CH 3- groups, CH 3CHz- groups, aromatic protons,

(3)

-C~X,

exchangeable protons etc.

Write down all structural elements you have determined. Note that some are monofunctional (i.e. must be end-groups, such as -CH 3 , -C=N, -NO z) whereas some are bifunctional (e.g. -CO-, -CH z-, -COO-), or trifunctional (e.g. CH, N). Add up the atoms of each structural element and compare the total with the molecular formula of the unknown. The difference (if any) may give a clue to the nature of the undetermined structural elements (e.g. an ether oxygen). At this stage, elements of symmetry may become apparent.

(4)

Try to assemble the structural elements. Note that there may be more than

one way of fitting them together. Spin-spin coupling data or information about conjugation may enable you to make a definite choice between possibilities. (5)

Return to each spectrum (JR, UV, mass spectrum, l3C NMR, lH NMR) in turn and rationalise all major features (especially all major fragments in the mass spectrum and all features of the NMR spectra) in terms of your proposed structure. Ensure that no spectral features are inconsistent with your proposed structure.

Note on the use of data tables. Tabulated data typically give characteristic absorptions or chemical shifts for representative compounds and these may not correlate exactly with those from an unknown compound. The data contained in data tables should always be used indicatively (not mechanically).

87

~

~.'

I

;

Chapter 9 Problems

9 PROBLEMS

9.1 SPECTROSCOPIC IDENTIFICATION OF ORGANIC COMPOUNDS

89

Problem 1

IR Spectrum (liquid film)

1718

2000

3000

4000

1600

1200

0.0

800

V (ern") 43

100 80 60

0.5

CIl

o

co

.>t:.

€'"

'"

CIl 0CIl

0

til

til

..c '"

..c

M+"

29

40 '5 20

Mass Spectrum

72

*

Y 40

UV Spectrum

1.0 '"

33.3 mg/10 ml 1.0 cm cell solvent: ethanol

C4H aO 80

120

160

200

240

1.5

280

200

250

m/e I

13C

I

I

I

I

I

I

I

I

300

350

A. (nm)

I

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

--J

I

--'~'__

--

II

II

LlLillL

solvent

proton coupled

proton decoupled

I I

III

I

200

I

I

160

I

I

120

I

I

80

I

I

40

I

I

o

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

TMS

1.

90

Problem 2

IR Spectrum

1715

(liquid film)

3000

4000

2000 1600 V (ern")

1200

100

800

Mass Spectrum

80

-"

co Q)

c.

60

45

Q)

40

absorption above 220 nm

74

'0

uv

No significant

M+"

Vl

co

.0

57

~

20

j

I,

C3 H 602 80

40

120

160

200

240

280

m/e

13C

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz. COCI 3 solution)

I DEPT CH2~

CH 3t CHt

U

solvent

proton decoupled

• I

I

I

200 1H

I

I

I

I

120

160

I

I

I

I

80

I

40

0

o(ppm)

NMR Spectrum

(200 MHz. COCI 3 solution) exchanges with 0 20

~

~ A r---

11

12

TMS

~

--1

I I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 9

r

Problem 3

IR Spectrum

2984

(liquid film)

1741

2000

3000

4000

1243

1600

1200

800

0.0

V (crn")

100

Mass Spectrum

43

0.5

80 "'" '"060 Q)

Q)

UV spectrum

(/)

'"

.a '0

40

1.0

29

solvent: ethanol 15.4 mg /10 mls path length: 1.00 cm

M+"= 88

Q'!.

20 ~

,I

40

I

C4Ha02 120

80

160

200

240

1.5

280

200

250

m/e

13C

350

NMR Spectrum

(50.0 MHz, CDCI3 solution)

DEPT CH 2

t

Ll

CH~

CH3~

proton decoupled

Il

solvent III

160

200 1H

300

A. (nm)

120

40

80

0

() (ppm)

NMR Spectrum

(200 MHz, CDCI3 solution)

TMS

10

92

9

8

7

6

5

4

3

2

1

o

s (ppm)

Problem 4

, IR Spectrum

c,

1744

(CCI4 solution)

100 .><

60

Q)

1200

800

Mass Spectrum

57

29

80

2000 1600 V (cm'")

3000

4000

Ctl Q)

Co

No significant UV

en

Ctl J::J

20

absorption above 220 nm

M+" = 88

40 '0

*'

I 40

120

80

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

13C NMR Spectrum

CH2

t CHat

solvent

I I

I

CHt

proton decoupled

I

I

I

I

(100,0 MHz, COCl a solution)

DEPT

I

I

200

• I

I

I

160

I

120

I

I

I

80

I

I

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, COCl a solution)

expansion

I

, 10

2.0

10

9

8

7

6

ppm

5

4

3

2

TMS

1

o

o(ppm) 93

Problem 5

IR Spectrum (liquid film)

2000 1600 V (ern")

3000

4000

1200

100

Mass Spectrum

27

80

800

107/109

"''"" Q)

0-

60

No significant UV

Q)

en

'"

.c

40 '0

absorption above 220 nm

M+"

~

186/188/190

20 ~ .11

40

80

C2 H4 Br2

,I,

120

160

200

240

280

mle

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

~ I

solvent proton coupled

I

proton decoupled

• 160

200 1H

120

40

80

0

o(ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

TMS

l' I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

94

I

0

s (ppm)

Problem 6

IR Spectrum (liquid film)

1716

3000

4000

100

1200

2000 1600 V (ern")

800

Mass Spectrum

43

UV Spectrum

80 "" '"0. 60 CIl Ql Ql

'"

solvent: methanol

.0

40 '0

M+'

0~

20

=86

I

40

80

120

160

200

240

280

I

I

I

m/e I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

,

solvent

proton decoupled

160

200

120

o s (ppm)

40

80

1H NMR Spectrum (200 MHz, CDCI3 solution)

TMS

I I

10

I

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

1

I

o

() (ppm)

95

Problem 7

2249

IR Spectrum (KBr disc)

2000 1600 V (crn'")

3000

4000

1200

100

800

Mass Spectrum 53

80 "'"

'" Q)

o,

60

No significant UV

Q) Ul

40

'"

.I:l

absorption above 220 nm

M+" = 80

40 '0

'#.

20

1

~ 40

80

120

160 m/e

200

240

280

13C NMR Spectrum

I

(100.0 MHz, CDCI 3 solution)

L

solvent

proton decoupled

- - - ' - - -

160

200

120

80

o

40

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI3 solution)

TMS

I

I

I

I

I

10

9

8

7

6

96

I

5

I

I

I

4

3

2

.

1

1

o o(ppm)"

Problem 8

IR Spectrum (liquid film)

3000

4000

2000

1200

1600

800

V (em")

100

Mass Spectrum

80 .,.,

57

'"a.

<J)

60

No significant UV

<J)

Ul

'"

absorption above 220 nm

.."

40 20

'0

M+"

*-

=114 «

1%)

99

II

I

80

40

120

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDC'3 solution)

solvent

proton decoupled

I

I

I

I

200

I

160

80

120

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDC'3 solution)

TMS

I

I

I

I

I

I

,

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o (ppm) 97

Problem 9 3458

IR Spectrum (CCI4 solution)

2000 1600 V (crn'")

3000

4000

1200

100 80 60

800

Mass Spectrum 59 -'"

to

Q> 0Q>

No significant UV

'"

to

.a

absorption above 220 nm

40 '0 20

M+'

*

=118 « 1%)

J

,I

80

40

I

I

I

120

160 m/e

I

I

200

240

I

280

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

sOIV~.1

proton decoupled

I

I

I

I

I

160

200

1H

I

I

120

I

40

80

0

NMR Spectrum

S (ppm)

..

(200 MHz, CDCI 3 solution)

:

:<

~

,;,',

;:>

Exchanges with

.. s,"

°2°

I

10

I

9

I

I

8

7

6

t~

"'

S-

TMS

I

1

I

I

I

I

I

5

4

3

2

1

-.1._

0

s (ppm) ;

98

Problem 10

IR Spectrum 1693

(KBrdisc)

3000

4000

100 80

2000 1600 V (cm'")

1200

800

Mass Spectrum

56

M+' = 112 """Q)

'"

0-

60

No significant UV

Q)

VI

'" '0

absorption above 220 nm

.J:J

40

0~

20 I,

,"

40

13e

80

120

160 m/e

200

240

280

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

proton decoupled solvent

200

160

120

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

TMS

I I

10

I

9

I

8

I

7

I

6

I

5

I

4

I

3

I

2

I

1

I

0 o(ppm)

99

Problem 11

IR Spectrum 1738

(liquid film)

4000

2000 1600 V (crn")

3000

800

1200

100

Mass Spectrum

80

~

60

~

M+' = 84

Ql

o,

No significant UV

'"

absorption above 220 nm

.0

40

'0 <J.

20

40

80

120

200

160 m/e

240

280

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

n U

proton decoupled solvent

160

200

120

1H NMR Spectrum

80

40

..

0

o(ppm)

expansion

(400 MHz, CDCI 3 solution)

2.2

10

100

9

8

7

6

1.8 PPM

5

TMS

4

3

2

1

o o(ppm)

Problem 12

IR Spectrum (Ijquidfilm)

2000

3000

4000

1600

1200

800

Mass Spectrum

80 60 40

0.0

V (ern")

0.5 Ql <J

~

C

M+"= 156

'"


-e'"0 ..c

..c '"

'0

1.0

127

29


20

UV spectrum

III

III

'"

5.00 mg 110 mls path length: 0.50 cm solvent: cyclohexane

contains a haloQen

II

1.5 40

80

120

160

200

240

280

200

250

role

13C

300

350

A(nm)

NMR Spectrum

No TMS in

~'~PI'

(50.0 MHz, CDCI3 solution) solvent

i

proton coupled

L

proton decoupled III

200 1H

160

120

80

40

0

o(ppm)

NMR Spectrum

(200 MHz, CDCI3 solution)

10

9

8

7

6

5

4

3

2

1

o

8 (ppm)

Problem 13 2989

IR Spectrum

689

(liquid film)

100 80

2000 1600 V (cm'")

3000

4000

1200

800

Mass Spectrum

63 -"

''""

0-

No significant UV

60 '"

VJ

'"

.0

40

'0

20

*'

65

absorption above

220 nm

I

I

M+'

83

981100/102

l,

~ II

I..

40

C2 H4 CI2

JJ

120

80

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled 61·. . . . 1.... ,

i'

"U

III •

f t

...

1IIIf'-........

'J

t

' ....

'. ,

•

"P'

'LU...

4'......

solvent ru I

I

I

I

I

120

160

200

I

I

roc

. ,i"

....

I

proton decoupled I

'A

I

I

I

I

40

80

0

" (ppm)

1H NMR Spectrum (200 MHz, CDCJ3 solution)

~

L

,

,

6.0

5.8

expansions

ppm

-

,

,

2.2

2.0

~

ppm

I

I

I

I

=:f I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

102

TMS ~

~ I

0

s (ppm)

Problem 14

IR Spectrum (liquid film)

3354

100 80

2000 1600 V (ern")

3000

4000

1200

800

Mass Spectrum

45 -'"

C1l

Q)

60

0-

No significant UV

Q)

Vl

C1l .0

absorption above 220 nm

40 '0 ?ft.-.

M+' =60 «

20

JIIHI

1%)

59

C 3H aO

I

40

120

80

160

200

240

280

m/e

solvent proton decoupled

•

200

160

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution)

expansions

10

I

I

4.5

4.0

9

8

ppm

7

6

I

,

1.5

1.0

5

TMS

ppm

4

3

2

1

o

o(ppm) 103

~I r>. " 0 ('r

~[

1\

Problem 15

IR Spectrum (liquid film) I

4000

I

I

3000

2000

1600

1200

600

V (cm" ) 100 80

Mass Spectrum

43 .><

'"

Q)

o,

60

Q)

No significant UV

1Il

40

'" '0

20

*'

.0

absorption above 220 nm

M+" 122/124

,I

120

80

40

C 3 H 7Br

II

1I.

160

200

240

260

m/e

13C

I

I

I

I

I

I

I

I

I

I

I

r

I

,

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

DEPT

CH 2 , CH 3t CHt

solvent

proton decoupled I

I

I

I

~

,

I

160

200 1H

I

I

I

120

I

40

80

0

s (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansions

-

1.\.,

,

,

,

, 4.0

4.6

,

,

,

,

2.0

ppm

I

1.4

, ppm

~

TMS

-

Ill.

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

104

I

0

s (ppm)

Problem 16

IR Spectrum 776

(liquid film)

2960

650

3000

4000

2000

1600

1200

800

V (ern") 100

Mass Spectrum

55

80

~ CD

a.

60

No significant UV

5l

co

41

.0

401-'0

M+"

absorption above 220 nm

126/128/130 < 1%

~

201-

40

I

80

I

I

120

160 m/e

I

I

200

240

I

I

280

I

I

r

I

I

13CNMR Spectrum

I

H-C-H I

I

(50.0 MHz, CDCI 3 solution)

H-C-H I

solvent

proton decoupled

• I

I

I

I

200 1H

I

I

I

160

120

I

I

I

80

I

I

o

40

8 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansions

TMS I

ppm

ppm

10

9

8

7

6

5

4

3

2

1

o

8 (ppm) 105

Problem 17

763

IR Spectrum (liquid film)

100 80

2000 1600 V (ern")

3000

4000

1200

800

Mass Spectrum

41 -"


Ql

o,

60

121/123

Ql III

No significant UV M+"= 200/202/204


absorption above 220 nm

40 '0 ~

20 ". II

40

I

13C

80

IJ

120

160 m/e

200

240

I

I

I

I

I

I

280

I

I

I

I

I

I

I

I

I

NMR Spectrum

DEPT CH2~

(100.0 MHz, CDCI3 solution)

CH3t CHt

solvent

~

proton decoupled

I

I

I

I

I

I

I

I

I

Problem 18

766

IR Spectrum (liquid film)

2960

80

2000 1600 V (cm'")

3000

4000 100

650

1200

Mass Spectrum

41

-

800

~

Ql

c-

No significant UV

60 3l

77

<0

.c

absorption above 220 nm

M+-

40 '0

'#...

j

20

156/158/160

79 107/109 ,11

40

80

C3H6BrCI

III

II

120

160

240

200

280

m/e I

I

I

I

I

I

I

I

I

I

I I

13C NMR Spectrum

H-C-H I

(50.0 MHz, CDCI 3 solution)

I

I

H-C-H

H-C-H

I

I

solvent

/

~.

proton decoupled

I

I

I

200 1H

I

I

I

160

I

120

I

I

I

80

I

40

I

0

o(ppm)

NMR Spectr um

(200 MHz, CDCI 3 solution)

TMS

expansions

-, r

, , , ,

4.0

10

9

8

I

, , ,

--------'

, ,

ppm

3.5

7

I

2.5

6

L

, , , ,

I

2.0 ppm

5

4

3

2

1

o o(ppm) 107

Problem 19

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

J I

,--

1 I

I

I

I

I

3.0

34

2.6

I

-)

J~l i

2.2

ppm

-

-

TMS

--i

1

'-'

l

I

10

108

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 20

IR Spectrum

1620

(KBrdisc)

100 80

2000 1600 V (em")

3000

4000

1200

800

Mass Spectrum

44

"''"" c. Q)

60

No significant UV

Q)


'"

absorption above 220 nm

.Q

40 '0 #,

20

Ii 40

120

80

160

200

240

280

I

I

m/e I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, 020 solution)

I

I 160

200

120

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, 020 solution) Note: there are 3 protons which exchange with the 020 solvent

H 20 and HOD in solvent

3.7 ppm

3.9

10

9

1.6

8

1.4 ppm

7

6

5

4

3

2

1

o o(ppm) 109

Problem 21

IR Spectrum

1600

(KBr disc)

2000 1600 V (crn'")

3000

4000 100

Mass Spectrum

30

80 ""co Q)

c,

60

No significant UV

Q)

en

co .c

40

absorption above 220 nm

'0 ;f!.

20 80

40

13C NMR Spectrum

120

200

160 m/e

..........,1.'.' • ".OJ •• : ...,/.".' ......." .......

240

280

I 4 .... t

h,

,cart.

WIU"M ,

(100.0 MHz,

"~

°

O2

.....

,

solution)

proton decoupled

160

200 1H

120

40

80

0

o(ppm)

NMR Spectrum

(400 MHz, 020 solution) H 2 0 and HOD in solvent

Note: there are 3 protons which exchange with the 020 solvent

..

I

expansions

10

110

J

i

i

3.2

3.0

9

ppm

8

,

i

2.2

2.0

7

ppm

6

5

4

3

2

1

0

s (ppm)

I1 \

Problem 22

IR Spectrum (liquid film)

3000

4000

1600 2000 V (ern")

100

800

Mass Spectrum

M+' 108

80

1200

UV Spectrum

.:.:

Amax 269 nm

ell


60

(I091QE

3.2)

78

Vl

ell .0

solvent: methanol

40 '0

93


20

j

l

j,

40

80

C 7H aO

120

160

200

240

280

m/e

13C NMR Spectrum (100 MHz, CDCI 3 solution)

lJJ

W

proton decoupled

160

200

solvent

• 80

120

0

40

o(ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution) expansion

TMS

10

i

i

7.2

7.0

9

8

7

6

5

4

3

2

1

o

o(ppm) III

Problem 23

IR Spectrum (liquid film)

2000 1600 V (crn'")

3000

4000 100

1200

800 UV Spectrum

Amax 243 nm (10910£ Amax 248 nm (10910£ Amax 252 nm (10910£ Amax 258 nm (10910£ Amax 264 nm (10910£ Amax 268nm (10910£

Mass Spectrum

79

80 ""
'"

0.

60


en

'"

J:J

40 15 *20

91

80

40

120

200

160

240

1.9) 2.1) 2.2) 2.3) 2.1) 1.9)

solvent: ethanol

280

m/e

13C NMR Spectrum (100 MHz, CDCI3 solution)

I

I

129 128 127

ppm

solvent I

I

I

129 128 127

proton decoupled

160

200

80

120

I

ppm

o

40

0 (ppm)

1H NMR Spectrum (400 MHz. CDCI3 solution) expansion

Exchanges with

°2°

j 7.6

10

112

7.4

9

7.2

TMS

ppm

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 24

IR Spectrum (liquid film)

2000 1600 V (cm'")

3000

4000 100 80

1200

0.0

800

Mass Spectrum

91

0.5

II)

o

c:

-"

11l

11l

€

II)

60 40

a.

0

UV spectrum

'"

II)

.Cl 11l

'" 11l .Cl

0.917 mg 110 mls path length: 0.20 cm

1.0

'0 '#

solvent: hexane

M+'

20

.n

I ,\,

170/172

120

80

40

160

C 7H 7Br 200

1.5

280

240

250

200

mle I

13C

I

I

I

I

I

NMR Spectrum

expansion

(50.0 MHz, CDCI3 solution)

I

I

I

I

ppm

130

I

i

140

130

I

I

160

200

~

140

solvent

proton decoupled

ppm

i

expansion

I

~

I

350

I

I

I

• I

I

I

80

120

300

A. (nm)

o s (ppm)

40

1H NMR Spectrum (200 MHz, CDCI3 solution)

r~

TMS

t

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

() (ppm)

113

r

Problem 25

2251

IR Spectrum (liquid film)

1200

2000 1600 V (ern")

3000

4000 100

Mass Spectrum

M+" = 117

80

800

.><

'"'"

77

0-

60 '" '" .0 '" 40 '0 ~

20 120

80

40

200

160

240

280

m/e

CH z' CH 3t CHt

i

i

130

129

r

I

T

T

I

i

ppm

i

i

129

I

I

I

expansion

~ do

proton decoupled

I

ppm

I

solvent

I

•

I

I

160

200 1H

I

~

(100.0 MHz, CDCI 3 solution)

I

I

I

expansion

NMR Spectrum

DEPT

I

I

I

I

13C

I

120

I

I

I

I

40

80

I

0

s (ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

I---

TMS -

J

10

114

I

9

1

I

I

I

I

I

I

I

8

7

6

5

4

3

2

I

1

0

s (ppm)

Problem 26

3290

IR Spectrum (liquid film)

3000

4000

1200

2000 1600 V (cm'")

800

UV Spectrum

Mass Spectrum

100

M+" 107

80

Amax 256 nm Amax 264 nm

""clIJ Ql

60

Ql

'"

lIJ

(log10~ 2.2) (log10~ 2.1)

~

solvent: ethanol

40 '0

oF-

-J,

~I ~

20

J

91

J

" 80

40

C 7H g N

.1.

120

160

200

240

280

I

I

I

role I

I

I

I

I

I

I

I

I

ll"'~"'"

13C NMR Spectrum (100 MHz, CDCI 3 solution)

1

DEPT

CH 2

1CHJ

I 1

proton decoupled

I

120

1

I

129 128 127

I

160

80

ppm

0

40

1H NMR Spectrum (400 MHz, CDCI 3 solution)

ppm

ll"'~""

solvent

200

I

129 128 127

CHt

o(ppm)

Exchanges with

D20

expansion

1

TMS 7.6

10

7.4

9

7.2

ppm

8

7

6

5

4

3

2

1

o s (ppm) 115

Problem 27

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

0.0

800

V (om")

100

Mass Spectrum

91

80

-'"
60

1I)

0.5

Q)

0.

92

Q)

40

'0

M+'=

;f?

20

I,

J

,I··

5.662 mg I 10 mls path length: 1.00 cm solvent: ethanol

CaH 100

I

120

80

40

UV spectrum

1.0

122

200

160

240

1.5

280

200

250

m/e I

I

I

13C

expansion

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

DEPT

CH2

f CH

3t

,

135

130

,

ppm

I

CHt

I

,

,

,

135

130

ppm

proton decoupled

solvent

f

I

,

,

I

I

160

200

I

I

,

I

80

120

40

0

() (ppm)

expansion

~.

(400 MHz, CDCI 3 solution)

expansion

I

3.9

7.2

-,

I

expansion

lH NMR Spectrum

7.3

350

li-

i

'::lL

!

300

A(nm)

•

3.8 ppm

2.9

2.8 ppm

Exchanges with D20

ppm

TMS

•

10

116

9

8

7

6

5

4

3

2

1

o

s (ppm)

Problem 28

3325

IR Spectrum (liquid film)

3000

4000

2000

1600

0.0

800

1200

V (crn")

100

Mass Spectrum

104

80

0.5

€o

Co

60

8 c

.>< III III

Ul

Ql Ul

77 78 79

III

.Q

40 '0
.Q

III

107

1.0

M+'=

20

UV spectrum

5.815 mg/10mls

122

path length: 1.00 cm

.1 j I.

80

40

I

13C

C 8 H 10O

.1

.1.

I

120

160 m/e

I

I

I

200

solvent: ethanol

1.5 u...................."'-o..J.................. ...L...".................l..o..I...I 200 250 300 350

280

240

A. (nm)

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, COCI 3 solution)

DEPT

CH 2 , CH 3t CHt

solvent proton decoupled

~.

I

I

200

160

80

120

o s (ppm)

40

NMR Spectrum

1H

(400 MHz, COCI 3 solution)

expansions

l i

7.5

~ ~

II

expansion

i

i

5.0

i

4.8

i

i

ppm

i

1.6

i

1.4 ppm

~

Exchanges i

with 02°

i

7.3

ppm

r-

---'

-'~

~

L

TMS ~

~

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o s (ppm) 117

Problem 29

IR Spectrum

1715

(liquid film)

2000 1600 V (crn")

3000

4000

1200

100

Mass Spectrum

43

80

0.0

800

0.5

Ql

o c

-"

'"

e'"

Ql

Co

60

0

91

Ql

UJ

'"

'0

M+'

;ft.

'"

1.0

.J:J

40

UV spectrum

UJ .J:J

solvent: cyclohexane 7.90 mg 110 mls path length: 0.50 cm

134

20 II

,I

II

120

80

40

C g H 1Q O

I.

160

200

240

1.5

280

200

250

m/e I

13C

I

I

I

I

I

I

I

I

I

300

350

A. (nm)

I

I

I

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

DEPT

CH2

1 CH

II

CHt

3t

I r

~

proton decoupled

...-J I

II

I

I

I

160

200 1H

I

I

I

I

solvent

120

40

80

0

<5

(ppm)

NMR Spectrum

(200 MHz, CDC'3 solution)

..-

~

TMS ~

!1~

10

118

9

8

L

7

6

5

4

3

2

1

o

<5 (ppm)

Problem 30

IR Spectrum (liquid film) 1690

2000

3000

4000

1600

1200

800

V (crn'")

100

Mass Spectrum

105

77

80

0.5

~ Q)

60 40

c-

~

'" '0

.c

M+"

<;e.

UV spectrum

1.0

134

1.075 mg /10 mls path length: 0.10cm solvent: ethanol

20

1

IJ

40

80

120

Cg H 1Q O 160

200

240

1.5

280

200

250

m/e

350

300

A(nm)

13e NMR Spectrum (20.0 MHz, CDCI 3 solution) solvent off-resonance decoupled

200 1H

160

120

80

40

0

NMR Spectrum

(100 MHz, CDC'3 solution)

I

10

15 (ppm)

I

~~

L

J

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

TMS

L 1

v;

0

15 (ppm)

119

Problem 31

IR Spectrum (liquid film)

1723

2000 1600 V (em")

3000

4000

100 80

1200

800

Mass Spectrum

105 .><

'0-" Q)

60

Q)

Vl

'"

D

40 '0

M+-

77

~

L ~"

20

,II

134

J

.,li

40

80

I

120

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDC'3 solution)

solvent II

160

200

120

o

40

80

0 (ppm)

lH NMR Spectrum (200 MHz, CDCI 3 solution)

I

i

I

I

9.7

9.5

3.7

3.5

J I

1.5

I

1.3 ppm

_~I

10

120

9

8

7

6

5

4

TMS

3

2

1

o s (ppm)

Problem 32

IR Spectrum (liquid film)

1686

2000

3000

4000

1600

800

1200

V (ern") 100 80

Mass Spectrum

105 .><

UV Spectrum

77


Amax 241 nm

0-

60

Q)

0

(10910£ 4.1)

M+"

en


148

40 '0

solvent: methanol

120

;/i.

20 .1.

Ju

80

40

I

,I.

,I

I

I

II

C1QH 12O

I.

120

160 m/e

I

I

200

280

240

I

I

I

I

I

I

I

13C NMR Spectrum

(50.0 MHz. CDCI 3 solution)

~xpansion proton decoupled

135

I

I

I

200 1H

I

..---- solvent

Iii

I

1

I

130 ppm

I

1

I

I

160

I

1

120

1

I

1

40

80

I

o

8 (ppm)

NMR Spectrum

(200 MHz. CDCI 3 solution)

,

,

3.0

2.0

ppm

1.0

TMS

10

9

8

7

6

5

4

3

2

1

o

8 (ppm) 121

Problem 33

IR Spectrum 1735

(liquid film)

2000 1600 V (ern")

3000

4000

100

1200

43

800

Mass Spectrum 57

80 60

"''Q""> c,

No significant UV

Q>

til

'"

85

.0

absorption above 220 nm

40 '0

~

20

M+' 158<1%

J

I

40

I

120

80

I

160 m/e

I

I

I

200

240

280

I

I

I

r

I

I

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

solvent proton decoupled

I

160

200 1H

I.•

I

120

I

I

o

40

80

0 (ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

TMS

--

-

10

122

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 34

IR spectrum (liquid film) , r

1725

3000

4000

1200

2000 1600 V (ern")

31

100

29

800

Mass Spectrum

45

80 ~ 4l

No significant UV

a.

60

Sl

t1I

absorption above 210 nm

M+'

J::J

40 0

74

20 I

III

40

C3H602

J.

80

160

120

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50,0 MHz, CDCI 3 solution)

proto"

=-~""'~_~_",".1j,,~. . ~ ~Ww!\'W~1f\I' l I

s_"LJ

proton _ decoupled _ _ _ _ _ _---il...-

I

I

I

200

1H

I

I

I

I

160

I

I

I

80

120

L

_ I

40

I

0

o(ppm)

NMR Spectrum

(100 MHz, CDCI 3 solution)

TMS expansion 4x

10

9

8

7

6

5

4

3

2

1

o o(ppm) 123

Problem 35

IR Spectrum (KBr disc)

1662

100 80

1200

2000 1600 V (ern")

3000

4000

800

Mass Spectrum

105

UV Spectrum

sc

Amax 258 nm Amax 330 nm Amax 388 nm

til

ll)

c.

60

ll)

40

a

20

*'

77

VI

,JJ

til

..0

40

I

80

I

I

M+"

(Io910E

4.2)

(Io910E

2.8)

(I091OE

2.2)

210

C14H1002 120

I

160 m/e I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

I

200

240

280

I

I

I

solvent: ethanol

I

I

I

I

Problem 36

IR Spectrum (KBr disc)

2000 1600 V (ern")

3000

4000 100 80

1200

0.0

800

Mass Spectrum

91

0.5

Q)

o c

..><

t'lI

-e0

t'lI

Q)

60

0.

(I)

Q) (I)

M+"

t'lI .0

40

.0 t'lI

uv spectrum

1.0

162

'0

165.3 mg 1100 mls path length: 0.2 cm

~

20

,I

I

40

120

80

160

solvent: ethanol

C14H 14

I,

200

240

1.5

280

200

250

m/e I

I

I

13C

I

I

I

NMR Spectrum

I

I

300

350

A. (nm)

I

I

I

I

I

I

I

I

- - Resolves into two signals at higher fielel

(50.0 MHz, CDCI 3 solution)

I DEPT

CH 2

f CHJ

CHt - - Resolves into two signals at higher fielel

proton elecoupled

I

I

solvent

I

I

I

I

I

160

200

I

I

80

120

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

TMS _ _ _ _ _ _-----'

10

9

8

\'--

7

I

" .....

6

5

4

3

------l

2

1

o

o(ppm) 125

Problem 37 3310

IR Spectrum (liquid film)

4000

2000

3000

1600

1200

800

V (crn'")

100

91

Mass Spectrum

106

80 60

-'"

C1l Ql 0.. Ql

'"

M+'

0

197

C1l .0

40


20

C 14H1SN 160

120

80

40

200

240

280

m/e I

13C

I

I

I

I

I

NMR Spectrum

1CH

CH z

3t

I

Jl:i

I

I

I

I

Sion

(100.0 MHz, COCI3 solution)

DEPT

I

,

,

129

128

ppm

CHt

JL:LSion i

,

129

128

I

proton decoupled

ppm solvent

.

I

I

160

200

120

o s(ppm)

40

80

r

lH NMR Spectrum (200 MHz, COCI 3 solution)

exchanges with O2

°

-r

-'~ I

I

I

10

9

8

126

7

6

TMS

l

I

I

I

I

I

5

4

3

2

1

I

0

s (ppm)

Problem 38

IR Spectrum (liquid film)

3000

4000 100 80

1200

2000 1600 V (ern")

Mass Spectrum

58 -'"

.,060 ., <1l

No significant UV

III

<1l .0

40 20

absorption above 220 nm

'0 'ffl"

M+" = 116 72 I

80

40

120

160

240

200

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI3 solution)

J

,,,100 decoupled 1

1----1----------------1-1 1 I I I I

200

160

120

_

L

1

I

o () (ppm)

40

80

I

1H NMR Spectrum (400 MHz, CDCI3 solution) expansion

2.4

2.2

TMS

2.0 ppm

I

10

9

8

7

6

5

4

3

2

1

o

() (ppm)

127

Problem 39

IR Spectrum

1713

(liquid film)

4000

2000

3000

1600

1200

0.0

800

V (ern")

100

Mass Spectrum

43

80

-'"

60

'" '"

0.5

Gl

u

co

''""

-e0'"

III

..c

0-

III

1.0 '"

..c

40

'0

99

oR-

20

I

.1 ' I.

.1

40

80

UV spectrum 104.1 mg/10 mls path length: 0.2 cm

M+' 114

C S H 1Q 0

I

120

160

200

240

solvent: ethanol

2

1.5

280

200

250

mle

300

A. (nm)

350

13C NMR Spectrum (20.0 MHz, CDCI3 solution)

I

H-C-H I

-CH

JC

proton decoupled

solvent

160

200

120

3

TMS

40

80

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

TMS

10

128

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 40

IR Spectrum (liquid film) 1746

2000 1600 V (ern")

3000

4000

1259

1200

100

Mass Spectrum

29

80

-'"

60

Q)

800

'"cQ)

45

No significant UV

<1l

'"

.0

M+'= 118 «1%)

40 '0 *20

j

,I 80

40

absorption above 220 nm

C S H 100 3 120

160

200

240

280

m/e I

13C

I

I

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz. CDCI 3 solution)

DEPT CH2

CH3t

•

I

CHt

OOILJ

proton decoupled I

I

I

200 1H

I

I

I

160

I

120

I

80

40

L I

0

o(ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

10

9

8

7

6

5

4

3

2

TMS

I 1

o o(ppm) 129

Problem 41

IR Spectrum (liquid film)

2000

3000

4000

1S00

1200

800

V (cm'") 100 80

Mass Spectrum

57 .>< ell Q)

0.

SO

No significant UV

29

Q) (J)

ell

absorption above 220 nm

..0

40 '0 ;f?

74

20

,II

I

120

80

40

13C

M+' = 130

I

I

I

1S0 m/e

I

200

I

C S H 1003

« 1%)

240

I

I

280

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDC'3 solution)

proton coupled

j

I

I

III I

I

I

I

160

200 1H

I

I

I

120

L

I

solvent proton decoupled

I

I

II

I

I

40

80

0

o(ppm)

NMR Spectrum

..

(200 MHz, CDCI3 solution)

expansion

L1

~

,--~

,

,

,

2.5

2.0

1.5

, ppm

TMS

-

----1

1

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

130

I

o s (ppm)

Problem 42

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (crn'")

100 80 60

Mass Spectrum 29

"'"


Ql Co Ql !Il


40

(;

'if!.

20

M+' = 146 «1 %)

45

,I

C 6H 10 04

.I

40

80

120

160

200

240

280

m/e I

I

I

I

I

,

I

I

I

I

I

I

13C NMR Spectrum

I

(50.0 MHz, CDCI 3 solution)

CH3t

DEPT CH2 '

CHt

solvent proton decoupled

I I

I

I

I

160

200

120

80

o

40

0 (ppm)

J

1H NMR Spectrum (200 MHz, CDCI 3 solution)

TMS

I 10

9

8

7

6

5

4

3

2

1

o o(ppm) 131

Problem 43

IR Spectrum

1742

(liquid film)

2000 1600 V (em")

3000

4000

100

1200

800

Mass Spectrum

43

80 ~


C.

No significant UV

60 I- 3l III

..c

absorption above 220 nm

40 (; 86

20

M+" = 146

I 40

80

120

160

« 1%)

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled

160

200 1H

120

o

40

80

0 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

-

TMS

l

10

132

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 44

IR Spectrum 1739

(liquid film)

100

800

1200

2000 1600 V (ern")

3000

4000

Mass Spectrum

115

80 "'III" c. 60 Q)

No significant UV

Q) UI

III

..c

absorption above 220 nm

59

40 '0 '#.

87

20 I.L

.I

I

40

80

M+" 146 < 1%

120

160

200

240

280

I

I

I

m/e I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

solvent

1

•

proton decoupled ,., .... It, t Pi" .t;

160

200

120

,J.,

:ih

..J....

ll ..........

80

l._.".. .

o

40

0 (ppm)

1H NMR Spectrum (400 MHz. CDCI 3 solution)

TMS

I

10

I

I

9

8

7

-

I

I

I

:

I

I

6

5

4

3

2

1

o o(ppm) 133

Problem 45

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

43

80

-'"

ell Q)

o,

60

No significant UV

Q) (/)

ell

absorption above 220 nm

.0

40 '0 20

*'

87

M+" = 146

« 1%)

120

160

I

40

80

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (20.0 MHz, CDCI3 solution)

C-H

C

TMS solvent

proton decoupled

j

III I

I

I

I

I

I

160

200

I

120

I

I

I

I

I

o

40

80

(5 (ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

I~ ~

.il I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

134

T 0

(5 (ppm)

Problem 46

IR Spectrum (liquid film)

1737

3000

4000

100

2000 1600 V (ern")

1200

Mass Spectrum

59

80

-'" Cll

60

Ql

800

Ql

Q.

No significant UV

'" Cll

115

..0

87

40 '0 20

absorption above 220 nm

*'

M+' 146

40

80

120

C 6 H1Q 0 4

160

200

240

280

mle

TMS

,

.11. I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 135

Problem 47

IR Spectrum (liquid film)

1747

2000 1600 V (ern")

3000

4000

100

1200

Mass Spectrum

43

80

-'"

60

(f)

800

'Co" Q)

No significant UV

Q)

'"

absorption above 220 nm

.D

40 '0

87

;f?

20

I

IJ,

40

M+' 146

I

59

C 6 H1Q 0 4 200

160

120

80

240

280

mle I

13C

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

CH z+ CH 3t CHt

DEPT

I

solvent m

proton decoupled

II I

I

I

I I

I

I

160

200

I

120

I

I

I

80

I

o

40

0 (ppm)

lH NMR Spectrum (200 MHz, CDCI 3 solution)

expansions

I

L

I

I

2.5

1.5

J I

I

I

4.5 ppm

5.5

I

"r: ~

I

I

I

I

I

10

9

8

7

6

136

r--"

~

~

-"

I

I

I

I

I

5

4

3

2

1

I

o o(ppm)

Problem 48

IR Spectrum 1736

(liquid film)

3000

4000

2000 1600 V (em")

100

1200

800

Mass Spectrum

101

80 "'.,l'll" 60 .,

Q.

129

No significant UV

II>

l'll .0

40

absorption above 220 nm

'0 >i'!...

0

M+"

20

1

Il

III

,1.1

40

80

174

120

CS H 1404

160

200

240

,

,

280

m/e I

I

13C

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

DEPT

t CH

CH 2

3t

CHt

solvent

proton decoupled

• I

I

I

200 1H

I

I

I

I

I

160

I

120

I

[ I

I

LL I

40

80

I

0

8 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansion I--~

-

--'

,

~

I

4.0

ppm

2.0

TMS

I 10

9

8

7

6

5

4

3

2

1

0

8 (ppm) 137

Problem 49

IR Spectrum (liquid film)

4000

100 80

2000 1600 V (crn'")

3000

1200

800

Mass Spectrum

57 .>t: III

Q)

60

c-

No significant UV

29

Q) Ul

III

.c

absorption above 220 nm

40 '0

M+"=174 «1%)

?ft.

100

20 I.

1,1

40

~

C aH 140 4

n

160

120

80

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

l

solvent

proton decoupled I

I

200 1H

• I

I

160

I

1

120

I

I

80

1

I

I

40

I

o

0 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

1_ _ _

TMS

1

138

Problem 50

IR Spectrum (liquid film)

3000

4000 100 80

2000 1600 V (ern")

1200

55

Mass Spectrum

71 .><

800

70

'C." Ql

60

No significant UV

Ql

'"'"

M+' = 158 « 1%)

.c

40

absorption above 220 nm

'0
20

C aH 1403 40

120

80

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz. CDCJ 3 solution)

I proton decoupled

Il

solvent

• I

I

I

I

I

I

160

200

I

I

I

120

I

80

I

I

o () (ppm)

40

lH NMR Spectrum (200 MHz, CDCI3 solution)

,--

k~" I

I

1.50 ppm

2.00

J

1L-JL-

TMS

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

() (ppm)

139

Problem 51

IR Spectrum (nujol mull)

4000

2000

3000

1600

1200

0.0

800

V (cm'")

100 80

Mass Spectrum

M+"

"''"" Q)

0

III

Q)

III

1.0

.0

40


I I

a 15.07mg/10ml !! 0.302 mg/10ml path length: 0.5 cm solvent: ethanol

,L

80

40

I

'"

C 6 H 4 Br2

20

13C

UV spectrum

.0

155/157

'" '0

Q)

o c:

€'"

234/236/238

c.

60

0.5

I

I

120

160 m/e

I

I

200

240

I

I

280

I

250

I

I

I

I

I

300

A(nm)

350

I

NMR Spectrum

(20,0 MHz, CDC'3 solution)

I

off-resonance decoupled

solvent II

proton decoupled I

I

I

I

1H

I

I

I

160

200

I

120

I

I

I

o o(ppm)

40

80

NMR Spectrum

(100 MHz, CDCI3 solution)

TMS

140

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 52

IR Spectrum (nujol mull)

3000

4000

2000 1600 V (ern")

100 80

1200

800

Mass Spectrum

152

UV Spectrum

C12H8Br2

-"" l\'l

Amax 264 nm

Q)

60

cQ)

l\'l

M+"

76

.Q

40 15 20

(1 09 10 1:: 4.5)

en

solvent: methanol

310/312/314

"*

11 40

,,-.II

80

L

120

160 m/e

200

240

280

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

C-H

C-H

C

C

solvent

120

80

proton decoupled

160

200

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

1

I

I

8.0

I

i

iii

7.5

7.0

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o o(ppm) 141

Problem 53

IR Spectrum (liquid film)

696

1200

2000 1600 V (em")

3000

4000 100

800

Mass Spectrum

125/127

80 """ 'a.Q"l Ql 60 rn

'" *"

.0

40 '0 20

M+· J,I,h

.l

,L"

J.

1.1.

120

80

40

160/162/164

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

I

proton decoupled

SOlve:

I I

I

I

I

I

I

160

200

I

I

I

120

I

80

I

o o(ppm)

40

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

V

-,

I

I

I

B.O

7.5

7.0

ppm

6.5

1

V

142

TMS

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

1-

0

o(ppm)

Problem 54

IR Spectrum (liquid film)

100 80

1200

2000 1600 V (em")

3000

4000

800

Mass Spectrum

121 ~

'a."

Q)

60

Q)

III

'"

.0

40 '0

o~ .

20

I 40

I

120

80

160

200

240

280

I

I

I

m/e I

I

I

I

I

,

,

DEPT

CH 2 , CH 3

t CHt

I

I

I

I

I

,

,

solvent

I

I I

I

200

,.

,

130 128 ppm

proton decoupled I

I

,

130 128 ppm

~~-Jl1

I

I

~pao']l

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

I

I

160

I

I

I

0

40

80

120

I

o(ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

expansion

Jl 7.6

7.4

ppm

JI

.1

TMS

-

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 143

Problem 55

IR Spectrum (KB'r disc) 3400

1720

2000

3000

4000

1600

800

1200

V (em") 105

100 80

Mass Spectrum

183

UV Spectrum

.><

Amax 253 nm (10910E Amax 259 nm (10910E Amax 264 nm (l0910E

III

'"

Q.

60 '" III fF)

.0

M+" =228 «

40 '0

1%)

~

20

,I.

I

IL

80

40

120

C14H1203

160

200

240

280

I

I

I

2.6) 2.7) 2.5)

solvent: ethanol

m/e I

I

I

I

I

I

I

13C NMR Spectrum (100 MHz, COCI 3 solution)

i

i

130

128

ppm

j[''"' OO proton decoupled

I

I

160

200 1H

solvent

,

,

,

130

128

ppm

120

I "j'..-J 40

80

0

S (ppm)

NMR Spectrum

(400MHz, CDCI 3 solution)

expansion

JlJl

Exchanges with D20

,

+

, 14.5

7.7

~ ,

13.5

7.5

ppm

Exchanges with 020

,

14.0

,

7.6

TMS

ppm

+

~

I

10

144

----r-

1

I

I

I

I

I

I

9

8

7

6

5

4

I

3

I

2

I

1

0

S (ppm)

Problem 56

IR Spectrum (KBrdisc)

3461

3326

3000

4000

1600

2000

800

1200

V (cm-1 )

100

UV Spectrum

Mass Spectrum M+" 110

80 ""III Ql

Amax 225 nm Amax 27S nm Amax 283 nm

0.

60

Ql

en

III

.Q

40

'0

(loglOE 3.5) (log lOE 3.4) (log 10 E 3.3)

"#.,

20

40

I

80

I

I

120

160 m/e

I

200

.'Ill

280

I

I

I

(100 MHz, CDCI 3 solution)

D~:IIl~:L.C;,3'~~4~': !"'I1l~.~'

240

11

I

13C NMR Spectrum

$' ,....

~

I

proton decoupled

I

I

~~-.-...".

1M.'n....... Wl ...

_ll/l¥"lWJt#... lIIlfIIlIlI.W1_. ..

r- '"">----

T

1IWI

....-.ll'IoollI_......... II"," t 'Ifi

.....

solvent

I 160

200 1H

solvent: methanol

C SHS 0 2

I I

J .Ii

120

80

40

0

o(ppm)

NMR Spectrum

(400 MHz. CDCI 3 solution)

expansion 1rr--r-

Exchanges with

0:0 ~vIN~

S '

-

TMS

0'90

i

'

680

ppm

2

1

I

10

9

8

7

6

5

4

3

0

8 (ppm) 145

Problem 57

IR Spectrum (CCI4 solution) I

4000

I

I

3000

2000

1600

I

I

1200

800

V (ern")

100

Mass Spectrum

M+- =168

80 "'co"
UV Spectrum

Amax 267 nm

153

(Io910E

2.8)

III

co

.0

solvent: ethanol

40 '0 *20

~Ij l'~J 40

80

I

l

C9H1203

I

120

160

200

240

280

m/e

13C NMR Spectrum (100.0 MHz, CDCI3 solution)

_ _J"--------J"-------

proton decoupled

160

200

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI3 solution) expansion

,

,

7.0

6.4

ppm

ppm

TMS

10

146

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 58

IR Spectrum (liquid film)

3000

4000

2000 1600 V (cm'")

100 80

105 .:s:.

40 20

0.0

800

Mass Spectrum

0.5

M+'

'"c-

<J

-eo'"

en .c

1Il

en .c

1.0 '"

'"

'0

*'

'I

II 1

40

~I 80

120

160 mle

200

I

240

I

I

1.5

280

I

UV spectrum 5.875 mg 110 mls path length: 1.00 cm solvent: ethanol

C 9H12

I,

I

I

13C

1Il

c:

120

1Il

60

1200

200 I

250 I

I

350

300

A(nm)

I

NMR Spectrum

(20.0 MHz, CDCI3 solution)

I

I

off-resonance decoupled

proton decoupled I

I

I I

I

I

I

160

200

I

I

I

I

o

40

80

120

I

I

0 (ppm)

lH NMR Spectrum (100 MHz, CDCI3 solution)

s I

I

I

I

10

9

8

7

L

TMS I

I

I

I

I

I

I

6

5

4

3

2

1

I

0

o(ppm) 147

Problem 59

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (em")

100

Mass Spectrum

105

UV Spectrum

80 "'" 'e-" 60

Amax 261 nm Amax 269 nm

Ql

Ql IJl

'"

J:>

40

'0 '$.

(109101':

2.7)

(109101':

2.5 )

solvent: methanol

20

I

I

40

I

80

120

200

160

240

280

m/e

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

I

I

solvent

proton decoupled

I

I

160

200

120

80

o

40

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

"

'.. .

.--

-

~

TMS

I

148

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

L

0

o(ppm)

Problem 60

IR Spectrum (liquid film)

4000 100 80

1200

2000 1600 V (ern")

3000

105

800

Mass Spectrum

UV Spectrum

-'" <1l

Amax 270 nm

Ql

0-

60

Ql VI <1l

40

'0

.Q

(109

10

£

2.6)

solvent: methanol

~. Q

20

I

I

l

I

80

40

120

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

~

13C NMR Spectrum (100.0 MHz. CDCI 3 solution)

I

i

I

I

I.

expan:JL

I

135 130 ppm

DEPT

CH 2 , CH 3

24

"''"jill

"

I

proton decoupled

I

I

I

I

III

ppm

135 130

I

I

I

I

solvent

I

160

200

I

I

+ CH +

I

i

i

24

i

I

20

I

I

ppm

I

ppm

I

40

80

1H NMR Spectrum (400 MHz, CDCI 3 solution)

I

'~":JL

I

120

i

20

0

8 (ppm)

resolves into 2 peaks at higher field

~~, J. ,.<;

.:."

.

."{

':

t I J.;

'~":Jl

r--

t

tL .

+

'~Jl

:1_,:

I

10

i

i

6.8

6.6

I

9

ppm

I

8

2.2

----{ I

7

I

6

I

5

2.0

I

4

TMS

ppm

I

3

I I

2

I

I

1

0

8 (ppm) 149

Problem 61

IR Spectrum (KBrdisc)

2000

3000

4000

1600

1200

0.0

800

V (crn'")

100

Mass Spectrum

119

80

0.5

60

III <J

c:

.><

a.

<1l Gl

€0'"

Gl

.0

III

III

'"

M+'

.0

40 '0

1.0

134

UV spectrum

'"

1.032 mg 110 mls path length: 1.00 cm

*"

20

I Ii

J.

J..

1

L

120

80

40

solvent: cyclohexane

C 10 H 14

IJ

13C

200

240

1.5

280

200

250

m/e

off-resonance decoupled I

160

I

I

I

I

I

I

I

I

I

300

350

A(nm)

I

I

NMR Spectrum

(20.0 MHz, CDCI3 solution)

1

III

off-resonance decoupled

proton decoupled I

I

I

TMS

solvent

j I

I

160

200 1H

I

I

lL 120

I

I

I

80

I

I

40

0

o(ppm) •

NMR Spectrum

(100 MHz, CDCI3 solution)

150

I

I

I

10

9

8

-r-

------1

TMS

1

J

I

I

I

I

I

I

I

7

6

5

4

3

2

1

I

0

o(ppm)

Problem 62

IR Spectrum

802

(liquid film)

3000

4000

2000 1600 V (crn'")

100 80

1200

800

Mass Spectrum

119

~

III

60

c-

M+"

~ .c '"

134

401-0

"#..

20

II 1,

I

"L

40

I

.t"

[I 80

I

I

1,1

120

160 m/e

I

I

200

240

I

I

280

I

I

I

I

I

I

,

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

J

solvent proton decoupled I

I

II I

200

I

I

I

I

160

I

120

I

80

I

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

TMS I

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 151

Problem 63

IR Spectrum (liquid film)

2000 1600 V (em")

3000

4000

100 80

119

""'"

Ql

Ql Ul

40

'0

UV Spectrum

Amax 274 nm Amax 277 nm

M+' = 134

a.

60

Mass Spectrum

'"

.t:J

'#.

(109101': 2.3) (109101': 2.3)

solvent: cyclohexane

20 I "

I

40

80

13e NMR Spectrum

1,1

120

160 m/e

200

240

280

expansion

(100.0 MHz, CDCI3 solution) ~

i

140

~

i

130 ppm

J

solvent

I

200

120

160

expansion

,

,

20

15

ppm

expansion

,

,

20

15

40

80

0

() (ppm)

1H NMR Spectrum (400 MHz, CDC'3 solution) expansion

lr -=

I--

,

-

152

I

I

I

10

9

8

7

,

2.2 2.0

,

TMS

-

ppm

1

I

I

I

I

I

I

6

5

4

3

2

1

I

o

() {ppm}

Problem 64

IR Spectrum (KBr disc)

4000

2000 1600 V (em")

3000

100 80

1200

800

Mass Spectrum

147

UV Spectrum

"'III"

Amax 278 nm Amax 274 nm Amax 270 nm

Q)

60

0. Q)

'"

III .0

M+'

40 '0

162

c!?:

(109 10 8

2.4)

(109108

2.4)

(109108

2.5)

20 solvent: methanol

40

80

120

160 m/e

200

240

280

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled

I

solvent

200

160

80

120

o

40

3 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

TMS I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

3 (ppm) 15:

aus .

Problem 65

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

121

UV Spectrum

80 "" 'c.." 60 Vl

Amax 232 nm

Q)

(log lO E 3.4)

Q)

'"

Amax 248 nm (log 10E

;f<.

Amax

.0

40

'0

20

solvent: isooctane

120

80

40

265 nm (log lO E 3.4)

II I

I

3.5)

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

1:1 [I , , , ,

DEPT

15

CHA CH 3t CHt

solvent proton decoupled I

I

I

I

15

13

,

ppm

i

ppm

I

I

I

160

200

13

, , , ,

•

II

I

I

I

120

I

I

I

I

40

80

I

0

(5

(ppm)

lH NMR Spectrum (400 MHz, CDC'J solution) expansion

expansion

JL

JL ,

2.7 2.6

expansion

ppm

1.85

~

1.75 ppm

1.3 1.2

ppm TMS

L

A

10

154

9

8

7

6

5

4

3

2

1

0 (5

(ppm)

.~

Problem 66

IR Spectrum

3348

(KBr disc)

3000

4000

2000 1600 V (ern")

1200

100 80

Mass Spectrum 44

-"

'"Co Q)

60

800

43

M+"

Q)

No significant UV

59

If)

'"

.0

40

'0

absorption above 210 nm

~

20180

40

120

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz. COCI3 solution)

proton coupled

L

rol~oll

proton decoupled

~~4jP~""."~1".(i""_~~~ "'~

200

160

120

80

40

0

() (ppm)

1H NMR Spectrum (200 MHz. COCI 3 solution) exchanges with 0 20 on warming

/ TMS

I I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

() (ppm)

155

Problem 67

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

SOO

V (cm'") 100

Mass Spectrum

31

SOI-~
c,

60

No significant UV

~

ctl .1:J

40

absorption above 220 nm

'0 ~

M+" = 104 «

45 61

20

,I

1,1

C4H S03 120

SO

40

1%)

. 76

160

200

240

2S0

m/e I

I

I

I

I

I

I

I

I

f

I

I

13C NMR Spectrum (50.0 MHz, COCI 3 solution)

I

• j.

solvent proton decoupled I

I

I

I

160

200 1H

120

I

I

I

o

40

80

0 (ppm)

NMR Spectrum

(200 MHz. COCI 3 solution)

expansions

exchanges with 0 20

t

3.6

4.0

4.4

ppm

1.4

1.2 ppm

TMS

10

156

9

8

7

6

5

4

3

2

1

o o(ppm)

Problem 68 2266

IR Spectrum (liquid film)

1749

3000

4000

100

1200

2000 1600 V (cm")

Mass Spectrum

68

80

.><

60

II)

800

III II)

c-

No significant UV

lJ)

III

absorption above 220 nm

.D

40

'0 'ifl.

20

U

J~J

86

M+' 113

I

80

40

120

160

240

200

280

m/e I

I

13C NMR Spectrum (50.0 MHz. CDCI 3 solution)

DEPT

CH 2

f

CHat CHt

proton decoupled

I L

I

solvent

•

Problem 69

IR Spectrum (liquid film)

2000

3000

4000

1714

1600

1200

800

V (ern")

100 80 60

Mass Spectrum

45 -'"

co

43


No strong UV

lJ)

co

..c

40

'0

20

*'

absorption above 220 nm M+" 88 73

I,JI 40

C4 H a0 2

~

.1

120

80

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13e NMR Spectrum (50.0 MHz, COCI 3 solution)

DEPT

Ij

CH 2 , CH 3t CHt

proton decoupled

I

I

I

I

I

160

200 1H

I

I

120

l

J

solvent

I

I

I

I

I

I

40

80

0

o(ppm)

NMR Spectrum

(200 MHz, COCI 3 solution)

expansions

~L---A, , ,

4.5

I

10

158

4.0

ppm

, ~ exchanges with 0 20

,

,

,

2.0

1.5

ppm

I

I

I

I

I

9

8

7

6

5

TMS

~

1

I

I

I

I

4

3

2

1

I

o

o(ppm)

Problem 70 3410

IR Spectrum

1705

(liquid film)

100 80 60

800

Mass Spectrum

43

UV Spectrum

~

'"a.cv

58

cv

III

'"

M+· =

.0

40 'i5 20

1200

2000 1600 V (ern")

3000

4000

116 « 1%)

solvent: hexane

*' 1.1.1"

I

I,

I,

80

40

120

200

160

240

280

m/e I

I

I

I

I

13C NMR Spectrum

-CH 3

(50.0 MHz. COCI 3 solution) I

H-C-H I

solvent

C

- CH 3

C

I

J I

I

I

200

I

I

I

160

I

120

I

I

I

I

I

40

80

0

() (ppm)

lH NMR Spectrum (200 MHz, COCI 3 solution)

exchanges with 0 20

• ~

I

I

I

I

I

I

10

9

8

7

6

5

-

-

-

r-

-

TMS

--'

I

I

I

I

4

3

2

1

I

0

() (ppm)

159

Problem 71

IR Spectrum

1740

(liquid film)

2000

3000

4000

1S00

1200

800

V (em") 100

Mass Spectrum 43

80

"''"" Q)

0-

SO

No significant UV

Q)



'"

absorption above 220 nm

.0

40

'0

20

*'

56

M+' = 116 «

73

l

1%)

CS H 1202

.1

II

1S0

120

80

40

200

240

280

I

I

I

m/e I

I

13C

I

I

I

I

I

I

I

,

I

NMR Spectrum

(100 MHz, CDCI 3 solution)

DEPT

CH 2 • CH 3t CHt

solvent

proton decoupled I

I

I

I

160

200 1H

I

I

I

120

I

lJ I

L,I I

I

40

80

0

o{ppm}

NMR Spectrum

(100 MHz, CDCI 3 solution) I

11 I

20 HZ

~

I

1/

~ J I

3.85 ppm

1.92 ppm

I

0.93 ppm

expansions at 400 MHz

-

10

160

9

8

7

6

5

!A.

4

3

2

1

o s (ppm)

Problem 72

IR Spectrum (liquid film)

1709

3000

4000

57

100180

1200

2000 1600 V (crn'")

::.:

800

Mass Spectrum

59

'"


Co

60

No significant UV


<Jl

'"

absorption above 220 nm

LJ

40 '0

Jl~,

'#.'.

20

M+'116<1%

I

80

40

I

I

120

160 m/e

I

I

I

200

240

280

I

I

I

I

I

I

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

solvent

t

I

proton decoupled

160

200 1H

120

40

80

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

1-

Exchanges with

°2° t

Offset

---.J

_

_~l,---I 13.0

10

I

I

11.0 ppm

12.0

9

TMS

8

7

-

-

6

5

4

3

2

1

o

o(ppm) 161

Problem 73

IR Spectrum (liquid film)

3376

1600

2000

3000

4000

1200

800

V (em") 100

Mass Spectrum

59

80

.><

60


'"

No significant UV

l/l

73

til

.c

absorption above 220 nm

40 '0 20

*'

.I

M+" '" 88 «

I

.II

40

80

1%)

C5H12O

160

120

200

240

280

I

I

I

mle I

I

13C

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDCI3 solution)

DEPT CH2 , CH 3t CHt

sOlvent~

proton decoupled

160

200 1H

120

I o

40

80

0 (ppm)

NMR Spectrum

(200 MHz, CDCI3 solution)

Exchanges with

°2° + TMS

10

162

9

8

7

6

5

4

3

2

1

o .,

s (ppm)

Problem 74

3305

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (crn'")

100

Mass Spectrum

30

f-

80 ~

III Co

60

No significant UV

3l


.c

absorption above 220 nm

40 '0 M+·

?f!..

101

20

j

,L

40

80

120

160 m/e

200

240

280

13C NMR Spectrum (50.0 MHz, COC'3 solution)

WLl

solvent

I

proton decoupled

200

160

80

120

40

o(ppm)

0

2H exchange with 020

1H NMR Spectrum (200 MHz, COCI 3 solution)

G )

---

I-

-!

TMS

V

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 163

a 1St

Problem 75

IR Spectrum

1740

(liquid film)

4000

2000 1600 V (crn'")

3000

1200

100

800

Mass Spectrum

80 "" a> '" 60

0.

No significant UV

a> rJl

40

'" '0

20

*"

..c

absorption above 220 nm

107/109

M+' 180/182

120

80

40

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

solvent proton decoupled

I

160

200

120

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

~

':0 ' ,',

i

,

4.8

4.0

ppm

ppm

TMS

10

164

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 76

IR Spectrum (liquid film)

1715

2000

3000

4000

1600

1200

800

V (ern") 100

Mass Spectrum

43

80

-'"

60

al

'c-a"l

75

No significant UV

1Il

'"

absorption above 220 nm

.0

40 '0
20

101

il

II

~

.j

40

80

I

M+' 132

120

CSH 1203

160 m/e

200

240

280

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

-CH 3 I

H-C-H I

C-H -CH 3

proton decoupled

C

solvent

1

TMS

L

200

160

120

80

40

0

o (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 165

Problem 77

IR Spectrum (KBr disc)

100 80

2000 1600 V (ern")

3000

4000

1200

800

Mass Spectrum

59

""m Q)

Co

60

No significant UV

Q)

In

m

83

.0

40 '0

absorption above 220 nm 101

~

20

120

80

40

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz. COCI3 solution)

solvent

I

;'

proton decoupled I

I

I

I

160

200 1H

I

I

I

120

I

80

40

0

o(ppm)

NMR Spectrum

(200 MHz. COCI3 solution)

~nges 0 with

Ir-

20

V-

----.-/'-I

I

10.0 ppm

11.0

-----'

----'

TMS

t

166

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm)

Problem 78

IR Spectrum

1729

(KBr disc)

3000

4000

100

1200

800

Mass Spectrum

69

41

80

2000 1600 V (ern")

..l<

97


Q) Q.

60

Q)

No significant UV

115

'"
absorption above 220 nm

.Q

40 '0

M+" = 160 «

;je.

20

40

C 7H 1204

142

j

1,1

1%)

J

I

80

120

160

200

240

280

m/e

13C NMR Spectrum (100 MHz, 020 solution)

....... ".)IM!J'A

.~ ~ ...

....

, ",., ....".

off-resonance decoupled

tl:Il"l

iM~""

..,_

dioxan reference __ 67.7 ppm

proton decoupled

II

200 1H

I 160

80

120

o s (ppm)

40

dioxan reference

NMR Spectrum

(100 MHz, 020 solution)

6H

3.7 ppm H20 and HOD in solvent

I

.

Note: all labile protons exchange in the O2 solvent

°

2H

10

9

8

7

6

5

4

3

2H

2

1

o

() (ppm)

167

Problem 79

IR Spectrum (liquid film)

1640

2000 1600 V (em")

3000

4000

1200

100

Mass Spectrum

72

80

..><

60

Q)

co Q)

800

44

Co

No significant UV

<Jl

co

absorption above 220 nm

.J:J

40

'0 ~

20

l 120

80

40

160

200

240

280

mle I

I

I

I

I

I

I

I

I

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

off-resonance decoupJed

proton decoupled I

l

I,

I

I

I I

I

I

160

200

TMS

solvent

I I

120

I

I

I

80

I

I

o

40

8 (ppm) .

1H NMR Spectrum (100 MHz. CDCI 3 solution)

TMS I

168

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

l

o

8 (ppm)

Problem 80

IR Spectrum (liquid film)

1200

2000 1600 V (em")

3000

4000

100 80

800

Mass Spectrum -'"

co CD

Co

60

No significant UV

CD

VI

co

absorption above 220 nm

.0

40 '0 ~

20

40

I

13C

80

I

I

120

160 m/e

I

I

200

240

I

I

280

I

I

I

I

I

I

I

NMR Spectrum

DEPT

(100.0 MHz, CDCI 3 solution)

I

CH 2 , CH 3t CHt

,

/

solvent proton decoupled

I I

I

I

200 1H

I

I

I

160

I

120

I

I

I

40

80

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

expansion

J ,

3.8

expansion

i

3.6 ppm

1.8

1.6

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 169

Problem 81

IR Spectrum (liquid film)

100 80

2000 1600 V (ern")

3000

4000

1200

Mass Spectrum

28 -'"

'c," Q)

60

No significant UV

Q)

III

'"

absorption above 220 nm

.0

40 '0


20

I~

1 40

80

120

200

160 m/e

240

280

13C NMR Spectrum (100.0 MHz, dioxan-D8 solution)

DEPT

CH 2 ' CH 3t CHt

proton decoupled

160

200

120

o () (ppm)

40

80

lH NMR Spectrum (400 MHz, dioxan-D8 solution)

TMS

l

170

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o s (ppm)

.

Problem 82

IR Spectrum

1108

(KBrdisc)

100 80

1200

2000 1600 V (ern")

3000

4000

Mass Spectrum

. 89

45

800

-"

III

Ql

60

0.

No significant UV

Ql 00

III

absorption above 220 nm

.Q

40

'0 ;je.

20 I

80

40

I

I

I

120

160 m/e

200

240

I

I

T

I

280

I

I

I

I

T

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

solvent

L.

proton decoupled I

I

I

I

I

I

160

200

I

120

I

80

o

40

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

TMS I I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 171

Problem 83

IR Spectrum (liquidfilm)

1600

2000

3000

4000

1200

800

V (ern") 100 80 60

Mass Spectrum

75

""'"

'a". '" '" '15

No significant UV

39

!Il

.0

40

77


M+'

, II,

20 1,1 n

absorption above 220 nm

110/112/114

I, I"

C 3 H 4CI 2 80

40

160

120

200

240

280

m/e

13C NMR Spectrum (50,0 MHz, CDC'3 solution)

proton coupled

solvent

160

200 1H

120

80

o

40

0 (ppm)

NMRS pectrum

(200 MHz, CDCI3 solution)

1,.--

expansion

expansion

with resolution enhancement

I 5,8

with resolution enhancement

. i

I

5.4

I

V-

I

4,2

ppm

I

4,0 ppm TMS

10

172

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 84

IR Spectrum 1740

(liquid film)

100 80

2000 1600 V (crn'")

3000

4000

1200

800

Mass Spectrum

43 -'"


0..

60

No significant UV

Q)

VJ
absorption above 220 nm

40 15

73

~

20

~,II

M+" = 150/152 «

1.11., I

40

1%)

,I

80

120

160

200

240

280

m/e

13e NMR Spectrum (50.0 MHz, CDCI 3 solution)

"

proton decoupled

200

160

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

SF 10

9

8

7

6

5

4

TMS

3

2

1

o o(ppm) 173

Problem 85

IR Spectrum

1720

(liquid film)

2000 1600 V (ern")

3000

4000

100 80

1200

800

Mass Spectrum

73 138

140

-'"

'"

Ql

0-

60

No significant UV

Ql Ul

115

'" '0

.c

40

absorption above 220 nm

M+" =

;f!.

20

,~I

IJ"

.11

80

40

194/196 « 1%)

I.

120

160

200

240

280

m/e

13C

NMR Spectrum

I

(50.0 MHz, COCI 3 solution)

lillL

solvent proton decoupled

I 160

200 1H

120

a

40

80

() (ppm) .

NMR Spectrum

(200 MHz. COCI 3 solution)

~ """'0"' I

I

I

4.5

4.0

2.0

TMS

I

1.0 ppm

- - exchanges with O2

°

10

174

9

8

7

6

5

4

3

2

1

0 () (ppm)

Problem 86

IR Spectrum (liquid film)

3000

4000

2000 1600 V (crn'")

1200

100 80 60

...,

29

800

Mass Spectrum

66

ell


No significant UV

VJ ell

.0

absorption above 220 nm

40 '0 :o!e. 0

M+" =

20

40

80

94 « 1%)

120

160

240

200

280

m/e I

13C NMR Spectrum

H-C-H I

(20.0 MHz, CDC'3 solution)

C-H

C

TMS solvent

proton decoupled

~~~lI'·T,,,,··h

200

~

.U

P'

160

120

"

80

"u ,I "11"

40

0

o(ppm)

lH NMR Spectrum (100 MHz, CDCI 3 solution)

J

I

I

I

I

I

I

j

I

10

9

8

7

6

5

4

3

J

~ I

I

2

1

TMS

I I

0

o(ppm) 175

Problem 87

2248

IR Spectrum (liquid film)

2000 1600 V (crn'")

3000

4000

1200

100

800

Mass Spectrum 43

80

41

No significant UV

60

absorption above 220 nm

40 M+"= 83 « 1%)

20

68 II

.j

j

80

40

120

160

200

240

280

I

I

I

role I

13C

I

I

I

J

I

I

I

I

I

NMR Spectrum

(125 MHz, CDCI 3 solution)

solvent

l

proton decoupled _ _ _ _ _ _ _ _ _ _ _ _ _ _J - -

I

I

I

I

I

I

160

200

I

I

120

J

m

- ' '- _ I

I

80

I

I

o

40

1H NMR Spectrum

0 (ppm) TMS

(100 MHz, CDCI 3 solution)

20Hz

expansions at 400 MHz

JL 10

176

I

I

2.26

2.03

9

8

7

J

I

1.07

6

5

4

3

2

1

0

o (ppm)

Problem 88 2114

3295

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (crn'")

100180

55

Mass Spectrum

82

..><

t'lI
Q.

60

No significant UV


III

t'lI

.c

40

absorption above 220 nm

'0
20 II

M+" = 83

II 80

40

120

240

200

160

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, COCI3 solution)

I

I

I

I

200 1H

III

;O'D

proton decoupled

I

I

I

160

I

I

I

80

120

NMR Spectrum

I

I

40

I

0

o (ppm)

Exchanges with 020

(400 MHz, COCI3 solution) expansion

1H

2H

2H

I~

, 2.5

2H

2H

I II

'----

I

I

2.0

1.5

TMS

I

10

9

8

7

6

5

4

3

2

1

0

o (ppm) 177

b

Problem 89

IR Spectrum

3410

(liquid film)

2000

3000

4000

1600

1200

800

V (em") 100

Mass Spectrum 43

80

-"

60

Ql VI

'Co" Ql

No significant UV

'"

J:l

40 '0

M+' =

71

absorption above 220 nm

86 « 1%)

~

20

.II

III

.111

C SH1QO 80

40

I

I

I

120

160 m/e

I

I

200

240

I

I

280

I

I

I

I

I

,

T

DC NMR Spectrum (50.0 MHz, COCI 3 solution)

DEPT

CH 2

f CH

3t

l

CHt

I

proton decoupled I

I

I

I

solvent I I

160

200

I

I

120

I

I

80

I

-,

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, COCI 3 solution)

expansion

10

178

I

I

6.0

5.5

9

8

exchanges with 0 20

7

6

5

4

3

2

1

o o(ppm)

Problem 90

IR Spectrum (KBr disc)

57

100 80 60

1600 2000 V (crn'")

3000

4000

800

1200

75

Mass Spectrum

""'-

<0

01l Co CD

No significant UV

U>

<0

Ll

40

absorption above 220 nm

45

'0 ';fl.,

20

104

M+"= 119

C4 H gN03

,I

I

80

40

120

160

240

200

280

m/e I

I

I

13C

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, 020 solution)

DEPT CH2 f CH3t CHt

proton decoupled

I I

I

I

160

200 1H

40

80

120

NMR Spectrum

0

~

(ppm)

expansions

(400 MHz, 020 solution) Note: there are 4 protons which exchange with the 020 solvent

4.3

4.1

ppm

~

l

Jl

3.6

3.4

ppm

1.3

1.1 ppm

lr-

,--

H20 and HOD in solvent

.

I

-

-

-

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

~

0

(ppm)

179

Problem 91

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

0.0

800

V (em")

100 80 60

Mass Spectrum

91

0.5

~

'"'"c.

<Jl .Q

'" '" '0

<Jl

1.0

.Q

40 20

8c

-e0'"

*-

'"

UV spectrum 5.30 mgl10 mls path length: 1.00 cm solvent: cyclohexane

M+" 1981200

'I I

.I

C 9H 11 Br

II

.Ii.

1.5

J

40

120

80

160

200

240

280

200

250

mle I

13C

I

I

I

I

NMR Spectrum

CH 2

I

I

I

I

I

II

t CH t 3

CH

t

----r'

- - Resolves into two signals at higher field

proton decoupled

I I

I

350

- - Resolves into two signals at higher field

(50.0 MHz, CDCI 3 solution)

DEPT

I

I

300

A, (nm)

I

I

1H NMR Spectrum

.. I

160

200

solvent

II

I

expans~

I

120

I

I

I

80

I

40

I

i

35.0

34.0

I

ppm

I

o

0 (ppm)

expansion

(200 MHz, CDCI 3 solution)

I

3.0

10

180

9

8

7

ppm

2.5

6

5

4

3

2

1

o o(ppm)

Problem 92

IR Spectrum

1553

1387

(liquid film)

100 80

2000 1600 V (ern")

3000

4000

1200

0.0

800

Mass Spectrum

43

0.5

41

..><

OJ

€

CD

60

CD

o

c:

OJ

0.

0 II) ..0 OJ

CD

II)

OJ ..0

UV spectrum

1.0

40 '0 o>R. .

M+' = 89 «

20

1%)

solvent: ethanol

C 3H 7N02

I~ 80

40

137.0 mg /10 mls path length: 0.2 ern

160

120

200

240

1.5

280

200

250

m/e I

I

I

I

I

I

I

I

I

I

300

A(nm)

I

350

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

DEPT

CH 2 • CH 3t CHt

solvent

proton decoupled I

I

I

200

I

I

I

160

I

I

I

I

I

80

120

LI

-1 40

I

0

o(ppm)

lH NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 181

Problem 93

1115

IR Spectrum (liquid film)

100 80

1200

..><

800

Mass Spectrum

57

29

co

Ql

60

2000 1600 V (ern")

3000

4000

0-

No significant UV

Ql

'"

87

co

.c

absorption above 220 nm

40 '0 ~

20

101

73

I~ ~I

II

40

M+" 130

160

120

80

C8H 18O

I

I

200

240

280

m/e I

13C

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, CDC'3 solution)

UL

proton decoupled solvent

- - - - - - - - - - " - - - - -

I

I

I

I

I

I

160

200

I

I

120

I

I

80

o

40

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI3 solution)

expansion

10

182

9

TMS

2.0

3.0

8

7

1.0

6

5

PPM

4

3

2

1

o

o(ppm)

Problem 94

IR Spectrum (liquid film)

2000 1600 V (ern")

3000

4000

100

1200

Mass Spectrum

91

80

-"

60

Q)

800

0.0

0.5

Q)

"'-

92

€0

UV spectrum

.c

1.430mg /10 mls path length: 2.00 cm

II)

II)

<1l

<1l

.c

M+"

40 '0

1.0

134

~

20 1,1 IJ,.L

~,

,I

40

13C

Il>

u c:

<1l

<1l

l

J 120

80

solvent: hexane

C1QH 14

160 m/e

200

240

1.5

280

200

250

300

A. (nm)

350

NMR Spectrum

(20.0 MHz, CDCI 3 solution) I

H-C-H I I

I

H-C-H

H-C-H

I

I

-CH

3

expansion

,

TMS

130 solvent

proton decoupled

200

160

1H NMR Spectrum

120

I~ I

(400 MHz, CDCI 3 solution)

80

o

40

0 (ppm)

expansions

~L

expansion

I

i

2.8

2.6

i

,

i

1.6

1.5

1.4

i

1.7

1.1

1.0

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 183

Problem 95

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

119

UV Spectrum

80 1a

Amax 262 nm

Q)

0.

60 :ll to

(lo910E 2.5)

solvent: ethanol

.D

40 '0
I

20

II

h

77

,I"

II.~.

I

120

80

40

I.

200

160

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

expansion

solvent

~'-J

i

128

124

r

I

I

r

ppm

C proton decoupled

160

200

120

80

40

0

o(ppm)

1H NMR Spectrum (600 MHz, CDC'3 solution)

I

expansion

..

V \ i

ppm

V--

I

10

184

c-

j

7.4

7.2

j

TMS

I

I

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

1

I

o

o(ppm)

Problem 96

IR Spectrum (liquid film)

1200

2000 1600 V (ern")

3000

4000

100

Mass Spectrum

105

80

800

UV Spectrum

.:.<
C.

60

Ql



.>J

40 '0 ~,

20 I

u

40

I

80

I

120

160 m/e

I

I

I

I

200

280

240

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CH 2 , CH3t CHt

I r

,

/

I

solvent proton decoupled

I I

I

I

200

I

I

I I

i

I

160

I

80

120

I

I

I

o

40

1H NMR Spectrum

,

,

7.5

7.3

10

9

expansion

expansions

(400 MHz, CDCI 3 solution)

i

ppm

•

2.8

8

7

i

1.8

2.7 ppm

6

5

i

I

1.7 ppm

4

0 (ppm)

1.45

3

1 ,

•

1.35 ppm

2

1.05

1

0.95

o o(ppm) 185

Problem 97

IR Spectrum (liquid film)

4000

2000

3000

1600

1200

800

V (ern")

100

Mass Spectrum

57

UV Spectrum

92

80 60

""CD'" 0-

Amax 260 nm

91

CD

(I0910c

2.5)

\

U>

'"

.D

solvent: methanol

40 '0

;f!.

M+"

20

I.

40

80

120

1,148

200

160 m/e

240

280

13C NMR Spectrum (50,0 MHz. CDC'3 solution)

solvent

160

200

120

80

o

40

(5 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution)

expansion

I

,

7,5

7.0

ppm

TMS

10

186

9

8

7

6

5

4

3

2

1

o

(5 (ppm)

Problem 98

IR Spectrum (liquid film)

3000

4000

1200

2000 11600 V (em- )

100

800

Mass Spectrum

147 139/141

80

""
60


40

'0

M+'

cf!..

182/184

Co

tJl

co

J:J

~.1 ~I, ,~

20

40

IJ.

,I

'~I

120

80

C11~5CI

160

200

240

280

m/e I

13C

I

I

I

I

I

I

I

I

I

- - Resolves into two signals at higher field strength

(50.0 MHz, CDCI 3 solution)

DEPT

I

I

NMR Spectrum

CH z' CH 3t CHt

1 - - Resolves into two signals at higher field strength

solvent

proton decoupled I

I

I I

200 1H

I

I

II

I

I

160

I

120

I

I

II I

80

40

I

0

o(ppm)

NMR Spectrum

~~JL_

(200 MHz, CDC'3 solution)

10

I

9

8

7

j

I

2.75

2.5

6

expansion

I

1.5

ppm

5

4

1.0 ppm

3

2

1

o o(ppm) 187

Problem 99

IR Spectrum

1718

(liquid film)

4000

100 80

2000 1600 V (ern")

3000

1200

800

Mass Spectrum

43

UV Spectrum

119

"''"" a.

Amax 262 nm

(l)

60

,

(l)

"''"

.c

40

(I091O E 2.5)

M+"

'0

solvent: methanol

176

~

20

II L

I.

,.I.""jll

I

120

80

40

161

I.

I

C 12 H16 0

160

200

240

280

m/e I

I

I

I

I

I

13e NMR Spectrum

I

I

CH3

t

CH

lc";oo

t

I

I

I

I

125 ppm

II

• solvent

I

II

proton decoupled I

I

I

I

I

I

J

160

200

1H

I

1

I

130 .'

I

125 ppm

130

t

I

lL~";oo

(50.0 MHz, CDC'3 solution)

DEPT CH2

I

I

I

I

I

80

120

I

I

o

40

0 (ppm)

NMR Spectrum

(200 MHz, CDCI3 solution)

10

188

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 100

1693

IR Spectrum (CCI4 solution)

4000

2000 1600 V (crn'")

3000

100 80 60

1200

800

Mass Spectrum

183/185

UV Spectrum

~

ltJ Ol

c-

Ol

(fl

155/157

ltJ

.a

solvent: ethanol

M+" = 198/200

40 0 f1!..

20 1

Il

40

80

CaH 70Br

11

120

200

160

240

2ao

mr e I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, COCI3 solution)

DEPT

CH 2 , CH 3+ CH+

proton decoupled

solvent

I

I I

I

I

200

I

I

I

160

I

.

II I

120

I

I

I

40

80

0

() (ppm)

1H NMR Spectrum (200 MHz, COCI3 solution)

expansion

JJL 7.8

-

7.2 ppm

~

TMS

I

I

I

I

I

10

9

8

7

6

I

I

I

5

4

3

I

2

1

0

() (ppm)

Problem 101

IR Spectrum (liquid film)

, UV spectrum 0.104 mg/10 mls path length: 1.00 cm solvent: ethanol

250

I

I

I

I

I

I

I

I

I

300

I

I

350

A (nm)

I

13C NMR Spectrum (20.0 MHz, CDCI3 solution) C-H

C-H

-CH proton decoupled

I

C

CC

I

II I

I

I

l

I

I

160

200

3

I

120

I

I

I I

I

80

TMS

I

40

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

3H

2H

2H TMS

I

10

190

I

9

1U I

I

I

I

I

I

I

I

8

7

6

5

4

3

2

1

I l

0

o(ppm)

Problem 102

1773 1738

IR Spectrum

875

(liquid film)

2000

3000

4000

1200

1600

800

V (crn'") 100

Mass Spectrum

119

UV Spectrum

80 "'" Q)

""a.

60

Amax 254 nm Amax 258 nm Amax 279 nm Amax 290 nm

91

Q)

'" ""

.0

40 '0

*'

20

M+" = 1541156

I,

.,1]

120

80

40

160

CS H 70CI

200

240

I

I

280

, (10910£ 4.3) (10910£ 4.2 ) (10910£ 3.3) (10910£ 3.0)

solvent: hexane

m/e I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDC'3 solution)

DEPT

CH 2

t CH

3t

l=~;OO

CHt

proton decoupled I

I

I

I

I

,

i

132

131

I

I

i

solvent

ppm

I

I

I

I

ppm

120

160

200

, 131

L

I

r. .----J

I

I

, 132

I

I

I

I

I

I

40

80

I

0

o(ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution) expansion ,.-

II

--'

I

,

,

,

8.0

7.5

7.0 ppm TMS

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o (ppm) 191

Problem 103 3500-2500

IR Spectrum

1688

(KBrdisc)

2000

3000

4000

1600

1200

800

V (em")

100 80

Mass Spectrum

M+- 152

135

UV Spectrum

""'" cQl

60

Ql rJ)

'"

.0

solvent: methanol

40 '0

oft.

20 I

III .111

•.1,,1

I

80

40

.1"

120

200

160

240

280

m/e

13C

NMR Spectrum

(100 MHz, COCI 3 solution)

DEPT

CH2

1 CHat

I

CHt

solvent

LJ

proton decoupled

160

200

I 1

1

120

40

80

0

o (ppm)

NMR Spectrum

1H

(200 MHz, CDCI 3 solution)

expansion

JL JL

exchanges with 0 20

~

I

8.1

~

I

I

I

I

8.0 7.0

I

I

6.9 ppm I--

I

13.0

12.0

,---

r-r-rr:

TMS

.--1

----1 I

10

192

I

-

I

I

I

I

9

8

7

6

5

I

I

4

3

I

2

1

o s (ppm)

Problem 104

IR Spectrum 1743

(liquid film)

1200

2000 1600 V (ern")

3000

4000

1229

100

UV Spectrum Mass Spectrum

108

80

800

Amax 252 nm Q0910E Amax 257 nm (i0 9 10E Amax 262 nm (I0910E Amax 264 nm (I0910E Amax 268 nm (I091OE

-'"


91

c.

60

43

Q)

U>


M+" 150

40 '15 ~. o

20

.I

.I

,l

,I

40

C gH 10 0 2

rJ

1,1.

120

80

200

160

240

2.2) 2.3) 2.2) 2.2) 2.0)

solvent: ethanol

280

m/e

13C NMR Spectrum (100 MHz, CDCI 3 solution)

expansion

1L I

I

128.5

128 ppm

,

¥,;'ppm I

proton decoupled

solvent

I

I

160

200

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion

~

~\ I

7.5

,

I

I

7.4

7.3

----

, ppm

--.J I

10

9

-

TMS

-

I

I

I

I

I

I

I

I

8

7

6

5

4

3

2

1

o o(ppm) 193

Problem 105

IR Spectrum (nujol mull) 1670

2000 1600 V (cm")

3000

4000

100

1200

Mass Spectrum

135

80

-"

60

Q)

800

co Q) a.

UV Spectrum

Amax

M+"

'" co

150

.0

270 (I091O E 4.2) solvent: methanol

40 '0 20

*

..J

I

I

n,

107

80

40

13C

J

Jt..

I

C g H1Q 0 120

160 m/e

200

240

2

280

NMR Spectrum

(15.0 MHz, CDCI 3 solution) solvent

l

I off-resonance decoupled

",,"0,,10 at 130ppm

l

.k

J

,l

,TMS

proton decoupled

l

I

I

160

200

120

I

o

40

80

0 (ppm)

1H NMR Spectrum (100 MHz, CDC'3 solution) 3H 3H

2H

U

194

I

I

I

10

9

8

2H TMS

~

L

.,

I

I

I

I

I

I

7

6

5

4

3

2

1

I

0

o(ppm)

Problem 106

IR Spectrum (liquid film)

1760

2000

3000

4000

1600

1200

800

V (crn'")

100

108

80

Mass Spectrum

UV Spectrum \

.>< ttl

Amax 265 nm Amax 271 nm


Co

60


VJ

107

ttl

.Q

40 '0 ~

M+' = 150

20 I

I

~

(109101> 2.6 )

solvent: methanol

I

J,

80

40

(109101> 2.6)

120

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

13e NMR Spectrum

.~'"~

(100.0 MHz, CDCI 3 solution)

DEPT

CH2

t CH

3t

I

,

CHt

,

24

,

,

I

20 ppm

"~"':L ,

proton decoupled

I I

I

I

200

I

I I

,

24

solvent

,

,

20 ppm

I

I

I

I

I

I

160

I

120

I

I

I

40

80

0

3 (ppm)

NMR Spectrum

1H

(400 MHz. CDCI 3 solution)

-

expansion

~

~

7.0

7.2

ppm

J

-

d

I

I

I

I

10

9

8

7

TMS

I

6

I

I

I

5

4

3

I

2

1

I

0

3 (ppm) 195

Problem 107

IR Spectrum

1724

(liquid film)

2000

3000

4000 100 .><

60

Ql

800

Mass Spectrum

119

80

UV Spectrum

l'll Ql

a.

VI

91

l'll .Cl

40

1200

1600

V (cm-1 )

'0

Amax

238 nm

(109101':

4.2) \

Amax

281 nm

(109101':

2.7)

;f!.

solvent: methanol

20 1.1

120

80

40

160

240

200

280

m/e I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

I

I

I

I

. JL"":'"' ,

,

,

132.5

130.0

I

I

I

ppm

I

~~~

CH 2 • CH3t CHt

slon

proton decoupled I

I

I

I

I

1H NMR Spectrum (400 MHz, CDCI 3 solution)

solvent

I-.-J I

I

I

I

I

40

80

I

0

() (ppm)

expansion

L

If I

196

, ppm

120

160

200

, 130.0

I

I I

, 132.5

8.0

JL

7.9

7.3

7.2

ppm

-

TMS

I

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

() (ppm)

Problem 108

IR Spectrum (liquid film)

3352

2000

3000

4000

1600

1200

800

V (cm'")

100

Mass Spectrum

UV Spectrum

M+"

80 ""III Ql

\

138

Amax 270 nm Amax 282 nm

c,

60

Ql

121

'"

III

.J::J

40

'0 ~

(109108

3.1)

(10 9 10 8 3.1)

solvent: hexane

20

C8H100 2 40

80

120

160

200

240

Note: UV spectrum not changed significantly on addition of base

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz. CDCI 3 solution)

I DEPT

CH2 , CH 3t CHt

proton decoupled I

I

I

I

200

I

I

IU

solvent I

I

160

I

120

I

LJ I

80

I

o s (ppm)

40

1H NMR Spectrum (200 MHz. CDCI 3 solution)

__ exchanges with D 20

10

9

8

7

6

5

4

3

TMS

2

1

o

() (ppm)

197

Problem 109

1085

IR Spectrum (CHCI3 solution)

2000 1600 V (cm'")

3000

4000 100

107

80

800

1200

Mass Spectrum

UV Spectrum

~

'"a. Ql

60

Ql VI

'" '0

.0

40

Note: UV spectrum changed significantly on addition of base

oR-

20

III, 80

40

13C

I

I

I

120

160 m/e

I

I

200

240

I

280

I

,

I

I

,

I

I

,

,

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

DEPT

I

CH2 • CH3t CHt

I solvent

proton decoupled I

I

'.

I I

I

I

I

I I

I

120

160

200

I

o s (ppm)

40

80

1H NMR Spectrum (400 MHz, CDCI3 solution)

Exchanges with D20

J

II

.

7.5

,

"-

7.0

ppm

198

9

8

7

-

-

.I 10

II-

6

5

4

TMS

1

3

2

1

0

s (ppm)

Problem 110 2209

IR Spectrum (nujol mull)

3000

4000

2000

1600

1200

800

V (crn'")

100

Mass Spectrum

145

80 "'ro" Q)

Co

60

Q) III

102

ro

.Q

M+"

40 '0 20

*

146

40

80

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled

120

160 m/e

200

240

280

,

Problem 111

IR Spectrum (KBrdisc)

2000

3000

4000

1200

1600

800

UV Spectrum

V (crn'") 100 80 ~

120

Ql

60

Amax 310 nm Amax 261 nm

Mass Spectrum a. ~

(I091OE 3.3)

(I091O E 4.3) \

solvent: methanol

M+" 199/201

'"

Amax 262 nm Amax 257 nm Amax 222 nm

.Q

40 '0 20

80

40

I

I

120

160 m/e

I

I

I

200

240

I

I

280

I

(lo910E

3.0)

(Io91O E 3.0) (Io91O E 4.0)

solvent: methanol 1 HCI

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

solvent proton decoupled I

I I

I

I

I

I

120

160

200

I

I

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion with resolution enhancement

I

7.5

~

6.5

I

ppm

TMS

-

II

L

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

200

I

0

o(ppm)

Problem 112

1666

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (crn'")

100 80 60

Mass Spectrum

135

UV Spectrum

~

4l 0-

~

'"

.0

401-'0 t/!.-,

20 d.

I

80

40

M+"

107

j

192

I

120

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

solvent

proton decoupled

I

I I

I

I

I

160

200

I

I

I

I

•

I I I

80

120

40

0

o(ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

10

9

expansion

8

7

I

I

I

8.0

7.5

7.0

6

I

6.5 ppm

5

4

3

2

1

o

o(ppm) 201

Problem 113

IR Spectrum

1766

(liquid film)

2000

3000

4000

135

100 80

1200

1600

V (cm-1 )

800

Mass Spectrum

UV Spectrum

-" «l

Amax 262

C1l

o,

60

\

2.6)

C1l

rn

Amax 269 nm

«l .&J

40

nm (109101>

'0

(109101> 2.6)

150

~

43

20

,II

C12H1602 200

160

120

80

40

I

I

I

solvent: methanol

M+"= 192

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13e NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

I

CH 2 • CH 3t CHt

"~:L I

proton decoupled I I

I

I

solvent

I

I

I

I

I

120

I

I

I

I

160

200

•

150 149 ppm I

I

I

I

I

40

80

0

s (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution) expansion

U 7.4

7.2

ppm

-r-r 10

202

9

8

7

TMS

6

5

4

3

-

2

I

1

0

o(ppm)

Problem 114

1729

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (crn'")

100

Mass Spectrum

177

UV Spectrum \

80 ""t1l

'c". '" t1l

60

l/J

.0

40 '0 I I

I

80

40

il

I

,I

I,

120

160 m/e

200

240

280

I

I

I

I

I

I

I

I

13C

M+" =192

135

0~

20

I

1

I

I

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

DEPT

1CH 3'

CH z

CH'

I

solvent

proton decoupled

I

I I

I

I

I

I

I

160

200 1H

I

I

I

120

I

I

I I

I

40

80

I

0

o(ppm)

NMR Spectrum

(400 MHz, CDC'3 solution)

expansion

U

I

,

8.0

7.5

PPM

If•

TMS

-

I

1

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm)

Problem 115

1514

IR Spectrum

1338

(CHCI3 solution)

2000 1600 V (em")

3000

4000

100

800

Mass Spectrum

M+' = 153

UV Spectrum

123

80 "" III Ql 60

1200

Amax 227 nm Amax 305 nm

a.

Ql U> III

..c

40

'0 'if!.

20

I IIII

~

(Io910E

3.9)

(Io910E 4.0)

solvent: methanol

l

II 80

40

C7 H 7N03

I

120

160 m/e

200

240

280

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

__UL...-_ solvent

proton decoupled

160

200 1H NMR Spectrum (400 MHz, CDCI 3 solution)

J

120

40

80

0

L

expansion

,

8.0

7.0 ppm

,..-

r-

-

TMS

-

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

204

S (ppm)

I

o

S (ppm)

Problem 116

lf-

I

10.5

r-r-:

V

'----

I

i

8.4

8.2

TMS

i

8.0 ppm

I

10 ppm ~

'--

10

9

8

7

6

5

4

3

2

1

0 () (ppm)

205

Problem 117

IR Spectrum 1699

(KBr disc)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

121

UV Spectrum

80 ""l1l c, 60 en Q)

"'max

225 nm

(I091QE

4.2)

"'max

250 nm

(I091QE

3.8)

Q)

l1l

.c

40 15
20

104

I~ 1 40

"'max 293 nm (I0910E 3.2)

l 80

M+"

120

151 < 1%

200

160

"'max

330 nm

2.6)

solvent: methanol

280

240

(I091QE

m/e

13C NMR Spectrum (100 MHz, CDCI 3 solution)

134

132

ppm

134

132

ppm

solvent - . proton decoupled

160

200 1H

120

o

40

80

0 (ppm)

NMR Spectrum

(400 MHz, CDCI3 solution) expansion

TMS

I

11

10

206

ppm

8.0

I

10 ppm

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 118

IR Spectrum

1698

(liquid film)

2000

3000

4000

1200

1600

V (cm'")

100

Mass Spectrum

UV Spectrum

80 "'" a:> 60

'0."

A. max

a:> en

277 nm

'"

.J:J

(10910£

4.2 )

solvent: methanol

40 a

92 107

~

20

j I

I, l

,I

120

80

40

200

160

240

280

mle I

I

I

I

I

I

I

I

I

r

I

13C NMR Spectrum (100.0 MHz, CDC'3 solution)

I

I DEPT

CH 2

1 CH3t

CHt

proton decoupled ~

I I

I

I

1

!

I

I

I

I

I

I

I

I

80

120

160

200 1H

I

I

LJ

solvent

0

40

8 (ppm)

J_ ~ expansion

NMR Spectrum

(400 MHz. CDCI 3 solution)

, , , ,

7.65

7.45

, , , ,

6.85

6.65 ppm

JJ

S

TMS

10

9

8

7

6

5

4

3

2

1

o

8 (ppm) 207

Problem 119

IR Spectrum (KBr disc)

4000

1511

2000

3000

1343

1600

1200

800

V (em")

100 80

~

60

Q)

Mass Spectrum

M+o147

101

UV Spectrum

> 4

10910£


!/l


40

'0 ;ft.

20

I

J

h

40

CSHSN0 2

.I,

160

120

80

200

240

280

m/e I

I

I

I

I

I

I

I

CH 2

f

I

I

1:''"'00

(50.0 MHz. CDC'3 solution)

DEPT

I

I

13C NMR Spectrum

,

,

80 ppm

85

CH 3t CHt

~

solvent

f proton decoupled I

I

I

200

, 160

I

,

I

, 120

I

l:"~;oo ,

,

l

80 ppm

85

,

I

,

I

40

80

I

0

s (ppm)

1H NMR Spectrum (200 MHz. CDC'3 solution)

~I

I expansion

TMS ---r

'------

I

"---"

208

I

i

8.25

7.75

I

ppm

I

I

I

,

,

I

I

I

I

,

10

9

8

7

6

5

4

3

2

1

I

o

s (ppm)

Problem 120

IR Spectrum

1766

(KBr disc)

2000

3000

4000

1685

1600

800

1200

V (em")

100

...

80

43

ttl

Q)

UV Spectrum

121

c-

60

Mass Spectrum

138

Sol

ttl

..c

40 '0

Amax 235 nm

(10910(;

4.1)

Amax 265 nm

(10910(;

3.0 )


solvent:

20

l

J

80

40

ethanol

120

240

200

160

280

m/e I

I

I

I

I

I

I

I

J

I

I

I

13C NMR Spectrum (100.0 MHz, COCI3 solution)

DEPT

CH2 ' CH 3t CHt

solvent proton decoupled I

I

I

200

"

•I

I

I

i

I

I

160

-I-

I

40

80

120

-I

0

o(ppm)

1H NMR Spectrum (400 MHz, COCI 3 solution) expansion exchanges with 0 20

---- J J ~~ ~

,

I

11.0

,

8.5

10.0

,

,

8.0

7.5

,

,

7.0 ppm

TMS

I I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

s (ppm) 20 4

Problem 121 3327

1680

IR Spectrum (nujol mull)

1600 2000 V (crn'")

3000

4000 100

1200

800

Mass Spectrum

120

0.0

0.5

80 ""III

(1)

60

0(1)

M+'

(/)

III .0

40

'0

20

*'

165

UV spectrum

1.0

92

0.172 mg /10 mls path length: 0.5 cm solvent: ethanol

137

.I,

II

..I..

40

,I,

80

C 9H 11 N0 2

I

160

120

200

240

1.5

280

200

250

m/e

13C

300

A(nm)

350

NMR Spectrum

(20.0 MHz. CDCI3 solution)

off-resonance decoupled

l

III

III

TMS

160

200 lH

120

80

o

40

0 (ppm) TMS

NMR Spectrum

(100 MHz, CDC'3 solution)

Ii

-

10

210

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 122

3380

3155

IR Spectrum

1646

(KBr disc)

4000

2000 1600 V (ern")

3000

100

1200

800

Mass Spectrum

121

\

80 1d Q)

Co

~

60

'"

M+"

.c

40 '0

165

20

80

40

160 m/e

I

I

I

I

I

120

13C NMR Spectrum (100 MHz, CDCI 3/CD 3SOCD3 solution)

200

240

I

280

I

I

I

I

I

I

solvent

C-H

C-H solvent I

-CH 3

H-C-H I

C C C

I

I

proton decoupled I

I

I

I

I

I

I

160

200 lH NMR Spectrum (400 MHz,CDCI 3/CD 3SOCD3

I

I

120

0 I

8

I

I

7

ppm

I

80

I

I

o

40

0 (ppm)

expansion

solution)

exchange with D 20 on warming

I

I

1'''''"'

/I

~

l----

vertical expansion solvent

-

-

-

•

solvent I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 211

Problem 123 3396 3334

IR Spectrum

1662

(KBr disc)

1200

2000 1600 V (ern")

3000

4000

120

100 80

"''"" c.

800

Mass Spectrum

UV Spectrum

Amax 312 nm

Q)

60

92

Q)

M+' 135

III

'"

(109108 4.3) \

solvent: methanol

.n

40 '0


20

"I.J, ,J.

I

120

80

40

I

I

160 m/e

I

200

240

280

I

I

I

I

I

I

I

I

13C NMR Spectrum

(100 Mz, DMSO-d6 solution)

DEPT

CH 2 • CH3t CHt

solvent

I

I

200

160

proton decoupled

~-,

I

I

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, DMSO-d6 solution) Exchanges with 020

r---

r-

,--

•

solvent residual ~ -,

TMS ----'

-

-----J

--'A

1

I

10

212

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 124

IR Spectrum (KBr disc)

1684

3000

4000

2000

1200

1600

800

V (cm'") 107

100 80

Mass Spectrum

UV Spectrum

:>(.

60

Amax 246 nm Amax 280 nm

106

til
M+" 149

III

til .0

40

'0

20

*'

(10910£

4.2)

(10910£

3.1)

43

I,. 40

solvent: methanol

1

Cg H11NO

80

160

120

200

280

240

mle 13C NMR Spectrum (100 MHz, COCI 3 solution)

DEPT

L

CH2 , CH 3t CHt

,

I

solvent

proton decoupled

I

I

II 160

200

120

40

80

0

o(ppm)

expansion

1H NMR Spectrum (200 MHz, COCI3 solution)

,

Exchanges with 020 on warming

,

~

7.6

solvent residual

,

,

7.4

,

t

, 7.2

Jl

I~

i

ppm

TMS

-f I I

10

-

I

I

I

I

I

I

9

8

7

6

5

4

I

I

,

3

2

1

1 o o(ppm) 213

Problem 125

3284

IR Spectrum (KBr disc)

4000

2000 1600 V (cm'")

3000

100

1200

800

Mass Spectrum

43

80

1658

UV Spectrum

108

~

Amax 250nm Amax 287 nm

'0." Q)

60

Q)

''""

.0

40 '0

M+'

137

oR.

i

J: 40

179

j

20 80

120

(I0910E

3.1) \

(I091OE

2.2)

solvent: chloroform

C lOH13N02

I

200

160

240

280

mle 13C NMR Spectrum (50.0 MHz, COCI3 solution)

DEPT

1 CHat

CHz

CHt

solvent

160

200

80

120

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, COCI3 solution) expansion

I

7.6

7.0

ppm

exchanges with 0 20 on warming

10

214

9

TMS

8

7

6

5

4

3

2

1

o

s (ppm)

Problem 126

3326

IR Spectrum

1667

(KBrdisc)

2000

3000

4000

1200

1600

800

V (em")

100

Mass Spectrum

109

UV Spectrum \

80

-'" Ol

60

Ql

Amax 250 nm Amax 285 nm

Ql

Co

M+"= 151

<J)

Ol

.0

40 '0

(10910E

4.1)

(10910E

3.6)

43

~ 0

20

solvent:

Ii

l 120

80

40

ethanol

C8H gN0 2 160

240

200

280

m/e

13C

I

I

I

T

T

I

I

I

I

I

I

I

1

I

NMR Spectrum

(100.0 MHz. DMSO-d6 solution)

DEPT

CH 2

1CH

3t

CHt

I solvent

1 proton decoupled I

I I

1

"I

I

I

I

I

I

I

120

160

200

I

I

1

40

80

0

s (ppm)

expansion

lH NMR Spectrum

Ll

(400 MHz, DMSO-d6 solution)

7.5

ppm

7.0

solvent residual

1

exchanges with D 20 on warming

TMS

10

9

8

7

6

5

4

3

2

1

o s (ppm) 215

Problem 127

IR Spectrum

1712

(liquid film)

1277

2000

3000

4000

1600

1254

1200

800

V (ern") 100 80

Mass Spectrum

121

UV Spectrum

~

Amax

'"

OJ

o,

60

149

OJ

<Jl

257 nm (I091OE 4.3)

M+"

'"

.n

solvent: methanol

194

40 '0

\

~

20

en H140 3 40

80

120

160 m/e

200

240

280

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

- - Resolves into two signals at higher field

- - Resolves into two signals at higher field

160

200

120

80

o a (ppm)

40

1H NMR Spectrum

~_M;O",~

(200 MHz, CDCI 3 solution)

I

I

4.6

I

I

I

I

3.8 ppm

4.2

-

I

I

1.2 ppm

1.6

v----

----

rr:'

TMS I

'-J

10

216

9

8

7

6

5

4

3

2

1

o

a (ppm)

Problem 128

IR Spectrum

1730

(CHCI3 solution)

2000 1600 V (ern")

3000

4000 100 80

1200

800

Mass Spectrum

121

""'c." l l)

60 ., ll)

UV spectrum

'" "5

.0

40

I,

1.

1

,.11

40

l

J,

l

I,

80

120

0.597 mg 110 mls path length: 0.2 em

194

134

0~

20

1.0

M+-

solvent: ethanol

I

160

C11H1403

200

240

1.5

280

200

250

m/e

300

A(nm)

350

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

C-H C-H

I

H-C-H -CH 3

-CH3

I I

H-C-H I

C

200

160

80

120

TMS

o

40

8 (ppm)

1H NMR Spectrum (100 MHz. CDCI 3 solution)

TMS

10

9

8

7

6

5

4

3

2

1

o

8 (ppm) 217

Problem 129 3295

IR Spectrum (liquid film)

2000 1600 V (ern")

3000

4000

1200

100

0.0

800

Mass Spectrum

91

80 ""III a. 60

0.5

Q)

o co

C1l

Q)

'" 40 a

0.766 mg 110 mls path length: 2.00 cm

..Q

134

C1l

C1l

1.0

..Q

oR.

M+"

20

II

,Il

,I,

I.

u

.l,

1.5 120

80

40

solvent: methanol

C1QH 1sN

149

,1",1

200

160

240

280

200

250

m/e I

13C

I

I

I

I

I

I

I

I

I

NMR Spectrum

(20.0 MHz, COCI3 solution)

. , ili~

.

off-resonance decoupled

~.

solvent

I

I

I

I

I

160

200

I

120

I

I

".L~ TMS I

I

I

I

o

40

80

350

I

11 I

300

A. (nm)

expansion x10 proton decoupled I

\.

UV spectrum

-e0 '"

Q)

0 (ppm)

1H NMR Spectrum (100 MHz, COCI3 solution)

exchanges with 0 20

•

TMS

septet

10

218

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 130

IR Spectrum (liquid film) 1750

2000 1600 V (cm")

3000

4000 100

1200

Mass Spectrum

121

80 "'" Sl0. 60 ~

800

0.0

0.5

Gl

g

ca

€

s

.c

UV spectrum

ca

77

~

1.0

40 '0

(/!...

33.9 mg /10 mls path length: 0.2 cm

M+"

20

LI

,ll

,I

40

J 80

solvent: ethanol

180 I.

120

160

200

250

m/e

300

350

A(nm)

13C NMR Spectrum (50.0 MHz. CDC/ 3 solution) Resolves into two signals at higher field __

Resolves into two signals at higher field - proton decoupled

200

160

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution)

V--

I I

10

.-

----

-

~

TMS

1

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 219

Problem 131

IR Spectrum 2276

(liquid film)

2000

3000

4000

1600

1200

0.0

800

V (em")

9

100 80

Mass Spectrum

\.'

CIl

Q>

60

0.5

.><

91

c.

M+'

Q> Ul

CIl .0

UV spectrum

119

1.0

40 '0 20

*'

I J,I~I

C 7H 5NO 120

80

40

160

200

240

0.80 mg /10 mls 9 path length: 1.00 cm Qpath length: 0.1 cm solvent: hexane

1.5

280

200

250

mle I

I

(100.0 MH, CDCI, 001'000)

.

DEPT

proton decoupled

I

I

I

I

I

I

I

,

,

I

350

expansion

13C NMR Spectrum

CH 2 + CH3+ CH+

I

I

I

300

A. (nm)

, 135

JUL'~~;oo

~

.

•

•

130

125 ppm

126

ppm

.__JlJL 1

"~:U 135

,

,

i

130

,

i

ppm

expansion

126

125

I

I

I

160

200

I

I

120

I

ppm

I

I

.--

solvent

i

I

80

o

40

0 (ppm)

1H NMR Spectrum expansion

(400 MHz, CDC'3 solution)

7.4

7.3

ppm

7.2

TMS

10

220

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 132

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (ern") 100 80

Mass Spectrum

60

.,'a-" ., en

40

'0

UV Spectrum

75

-"

\'

Amax

262 nm (109108 2.3)

'"

.0

solvent: methanol

0~

91

20

,I

I

40

135

j

J IJ

I J, 80

M+· =166 « 1%)

120

C10H1402 160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

1 CH

DEPT

CH z

3t

proton decoupled I

I I

I

200

I

II

CHt

I

I

160

~

I

I solvent

• I

I

I

I

120

U I

80

I

I

40

0

o(ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion

, 5.0

ppm

4.5

3.0

2.5

ppm

--- F

.r:

TMS

I

U

J. I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 221

Problem 133 IR Spectrum (CCI 4 solution)

1765

100

2000 1600 V (ern")

3000

4000

1200

29

800

Mass Spectrum

80 """ 'o," 60

UV Spectrum

Amax 269 nm Amax 263 nm

Q) Q)

Ul

40

110

57

'"

.c

M+" = 222 « 1%)

'0 ~

j

40

Ii

C 12 H140 4

I

120

80

(1091O E 2.7)

solvent: methanol

166

20

(1091OE 2.7) \,

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled

solvent

proton decoupled

I

I 160

200

120

80

o

40

0 (ppm)

lH NMR Spectrum (200 MHz, CDCI 3 solution)

expansion J

~ r-

222

',-I

i

2.5

2.0

I

r--

I

1.5 ppm

~

TMS ----'

~

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

1 I

o

o(ppm)

Problem 134

IR Spectrum (nujol mull) 1720

2000

3000

4000

1600

800

1200

0.0

V (crn'") 100 80

177

Mass Spectrum

0.5

'"

€ o en

o,

60

en

40

'0

CD

o

c:

149

.><:

CD

.0
166

UV spectrum

1.0

0.491 mg 110 mls

194

;fl..

path length: 0.2 cm solvent: ethanol

20

80

40

120

160 m/e

200

250

300

A. (nm)

350

13C NMR Spectrum (20.0 MHz. CDCI 3 solution)

off-resonance decoupled - - Resolves into two signals at higher field

proton decoupled

160

200

80

120

o

40

0 (ppm)

lH NMR

Spectrum (100 MHz, CDC1 3 solution)

---~

.:

f

0

l

---

TMS

1

J

I

I

1

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

o s (ppm) 223

Problem 135

IR Spectrum (liquid film)

1725

2000

3000

4000

1600

1200

0.0

800

V (ern")

100 80

Mass Spectrum

149

0.5

tlI

\

-e0

III

Q)

60

III

o

<:

~

0-

III

Q)

UV spectrum

..c

III

tlI

tlI

..c

40 15

1.0

177


2.010 mg 110 mls path length: 0.1 cm

M+'

20

II

I II,

II

II

C 12 H 14 0 4

I

160

120

80

40

solvent: hexane

222

~ JI

l

200

240

1.5

280

200

250

m/e I

I

I

I

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

.

I

..

I

I

I

I

J

J l

off-resonance decoupled

350

300

A. (nm)

l

C-H

C-H C proton decoupled

I

I

I

J I

I

I

I

160

200

TMS

solvent

I

I

120

I

I

I

I

40

80

0

s (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

J I

10

224

I

I

9

8

~

I

I

I

7

6

5

~

TMS

I

I

I

I

4

3

2

1

0'"

o(ppm)

Problem 136

IR Spectrum (liquid film)

1724

100 80

800

Mass Spectrum

177 ~

'"

149

CI) Q.

60

1200

2000 1600 V (cm")

3000

4000

CI)

'"'"

.Q

40 15

M+"

~

222

20

40

120

80

160 m/e

240

200

280

13C NMR Spectrum (50.0 MHz. CDCI 3 solution) I

I

135

130

I

./

I

130

135

160

200

ppm

120

ppm

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution) expansion

i

,

i

8.6

8.2

7.8

--'

I

10

--r-

1~

i

7.4 ppm

--

I

I

9

8

I~

TMS

I I

I

I

I

I

I

I

7

6

5

4

3

2

1

I

o o(ppm) 225

Problem 137

IR Spectrum (liquid film)

100 80

800

1200

2000 1600 V (ern")

3000

4000

110

Mass Spectrum

UV Spectrum

-"

Amax 220 nm Amax 274 nm

<0

Q)

60

c. Q)

'"

<0 .0

166

40 '0 20

*

(109

(109101':

solvent:

3.7) \ 3.3)

ethanol

I

I

80

40

120

160 m/e

200

240

280

I

I

I

I

I

I

I

I

101':

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CH 2 , CH 3t CHt

. proton decoupled I

I

I

I

I

I

I

I

Ll I

I

,

I

I

120

160

200

,

solvent

I

I

I

40

80

l

I

0

o(ppm)

1H NMR Spectrum (400 MHz, CDC'3 solution) expansion

J_

expansion

ul i

10

226

i

expansion

2.4

2.5

~

1.2

ppm

••

7.3

7.0 ppm

9

8

1.1

ppm

TMS

7

6

5

4

3

2

1

o

o(ppm)

Problem 138

IR Spectrum 1730

(liquid film)

100 80

1200

2000 1600 V (cm'")

3000

4000

800

Mass Spectrum

163

UV Spectrum \'

-"

Amax 223 nm Amax 275 nm

I1l

Ql

c.

60

1

l+·",~

Ql

en

I1l

.Q

40

'0 ;j?

20

104

135 II

160

120

80

40

200

Amax 280

-I

I

(Io9 10l'.: 3.1 )

281 nm (I0910l'.: 3.0 )

C10H1004 240

(Io91Ql'.: 3.9)

solvent r- ethanol

m/e I

I

I

I

I

I

I

I

I

T

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CH2

+ CH3+

CH+

I

r

I

solvent

+

proton decoupled

I I

I

I

I

I

200

I

I

I

120

160

1H NMR Spectrum (400 MHz. CDCI 3 solution)

I

I

40

80

0

o(ppm)

expansion

il 7.4

7.6

ppm

TMS

-

-

1

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 22~

Problem 139

IR Spectrum

1702

(liquid film)

2000

3000

4000

1200

1600

800

V (ern") 55

100 80

Mass Spectrum

.>< III

III

a.

60

No significant UV

III


M+"=

III

.c

42

40 '0

112

absorption above 220 nm

a"-

20 I

C7H12O

l'L 80

40

I

I

I

120

160 m/e

200

240

280

I

I

I

I

,

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

LlJ

solvent proton.decoupled

•I I

I

I

I

I

I

I

120

160

200

I

,

I

80

I

I

o

40

0 (ppm)

lH NMR Spectrum (400 MHz, CDCI 3 solution)

2.4

2.5

ppm

1.6

1.7

ppm

TMS

-

228

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm)

Problem 140

IR Spectrum (liquid film)

100 80

800

1200

2000 1600 V (crn'")

3000

4000

Mass Spectrum

91

UV Spectrum \.

~

I1l Q)

c,

60

Q)

'"

M+"= 92

I1l

..c

40 '0

solvent:

ethanol

,

1

I

I

~

20

J

C 7Ha 120

80

40

160

200

280

240

m/e

13e

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, CDCI J solution)

DEPT

CH2 , CH J+ CH+

I

,

solvent proton decoupled

I I

I

I

200

I

I

160

I

I

I

I

I

40

80

120

0

(5 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

expansion

expansion

expansion

~~

6.6

10

6.5 ppm

9

6.2

6.1

8

expansion

Jl j

I--

,

ppm

5.3

- 7

6

5

i

5.2 ppm

4

L 2.2

3

2.1 ppm

TMS

I

2

1

0

(5 (ppm)

229

Problem 141

IR Spectrum

1694

(liquid film)

2000

3000

4000

1600

1200

800

V (ern") 43

100 80

"'"

Mass Spectrum 69

CIl

\,'

Ql

60

c-

No significant UV

Ql

VI

CIl

..c

absorption above 220 nm

40 0 20

*'

M+' = 84 ,I

It.

120

80

40

200

160

240

280

mle I

I

I

I

I

I

I

I

I

T

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CH 2 , CH 3t CHt

proton decoupled solvent

I

I

I

I

I

I

160

200 1H

I

120

I

ul I

40

80

I

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

expansion expansion

~ 2.1

2.0

1.9

ppm

2.0

1.5

1.0

ppm TMS

10

230

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 142

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (cm'")

100

Mass Spectrum

41

\;

80

85

"'c," III oil

60

No significant UV

oil

'"

III .0

absorption above 220 nm

40 '0 cf!..,

20

40

120

80

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13e NMR Spectrum (100.0 MHz, CDCI J solution)

,

solvent proton decouPle~ I

I

I I

I

I

I

160

200 1H

I

120

I

40

80

l

I

0

o(ppm)

NMR Spectrum expansion

(400 MHz, CDCI 3 solution)

JL

Exchanges with D20

A i

11.5

12.0

expansion

ppm

1.7

1.5

ppm

1.1

ppm

0.9

TMS

10

9

8

7

6

5

4

3

2

1

o o(ppm) 231

'U£-

Problem 143

IR Spectrum

1668

(liquid film)

1600

2000

3000

4000

1200

800

V (ern") 105

100 80 60 40

Mass Spectrum \,.

~

'0-I"II

III

77

en

'"

.c

'0 of'.

M+"= 146

69

20

l,

I' J I

200

160

120

80

40

C10H10O

"

240

280

m/e I

13C

I

I

I

I

,

I

,

I

I

I

I

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

DEPT

I

CH 2 • CH 3t CHt

proton decoupled

I

I I

I

I

I

lH NMR Spectrum

,

,

7.5

232

9

40

80

Ll

I

0

o(ppm)

expansion

~

, ppm

,

,

2.6

2.5

l.- I,.....

---'

ppm

,

i

1.2

1.0

'-----,

8

Ir-

ppm

-

10

120

I

I

I

I

expansion

I--

,

•I I

~

expansion

8 .0

solvent

I

I

(4 00 MHz, CDCI 3 solution)

U

I

J

160

200

I

7

6

5

4

3

2

TM

s

I-

I

1

o

o(ppm)

Problem 144

JR Spectrum

1734

(liquid film)

2000

3000

4000

1600

800

V (ern") 100

Mass Spectrum .x.

80

etl Q) o,

60

No significant UV

Q)

III

etl .J:J

absorption above 220 nm

40 '0 ;f!.

20

55

83

,l

,I

I 100

113

80

40

120

200

160

240

280

mle I

I

,

I

I

I

I

I

I

I

13C NMR Spectrum

i

(100.0 MHz, CDCI 3 solution)

I

I

I

I I

"

~

I

f~

~

solvent proton decoupled

I I

I

I

200

I

I

I

160

I

I

~

I

80

120

o

40

0 (ppm)

lH NMR Spectrum (400 MHz, CDCI 3 solution) expansions

lAll

1

. 1.1. ppm

1.2

TMS

10

9

8

7

6

5

4

3

2

1

0

o(ppm)

1\

,.

I'~

23:

IMl

iII

j ..." _ . '

Problem 145

IR Spectrum

1728

(KBr disc)

2000

3000

4000

1200

1600

800

V (ern")

100

57

Mass Spectrum 98

80 "'"

'"

Q)

0-

60 40

No significant UV

Q)

.J::J '"'"

absorption above 220 nm

'0

;;R.

20 I,ll

..11.1

40

80

1.1

I

I

120

160 m/e

I

I

I

200

240

I

f

280

I

,

I

I

13e NMR Spectrum (100.0 MHz, CDCI3 solution)

DEPT

CH2

t CH

, 3t

t I

I

1H

lLJ

solvent

proton decoupled

~

28

I

CHt

I

I

200

160

I

I

I

120

I

I

I

40

80

+:'"~" ,

27

ppm

J~"~"

.

28

i

i

27

I

ppm I

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI3 solution)

expansion

10

234

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 146

IR Spectrum (liquid film)

2000

3000

4000

1654

1200

1600

800

V (crn'")

100 80

Mass Spectrum

30

43

-'" III

Q) Q.

60

No significant UV

Q)

.a'" III

absorption above 220 nm

58

40 '0 ;fl.

20 III

80

40

120

160

200

240

280

m/e I

13C

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz. CDCI 3 solution)

DEPT

CH 2

t CH

3t

CHt

,I

solvent proton decoupled I

I

lJ

I I

I

I

I

160

200

I

120

1H NMR Spectrum

I

80

40

0

o(ppm)

expansion with irradiation (decoupling) at 15 7.4 ppm

(200 MHz, CDCI 3 solution)

'---

expansion

M I

f

3.0

!

exchanges with 0 20 on warming

~.

t-

t

~.

fi

10

9

2.0

2.5

8

7

6

5

4

r-

~

ppm

--

Y-

l h

L I

I

3

---'

TMS I

2

1

0

o(ppm) 235

5k

Problem 14i

3283

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100 80

Mass Spectrum

30

\ ..

.><

'"

Q)

60

0-

No significant UV

Ql


co

absorption above 220 nm

.n

40 '0 ~

J,~

20

M+"=

C4H12N 2 200

160

120

80

40

88 « 1%)

240

280

m/e I

13C

I

I

I

I

I

I

T

I

I

I

T

NMR Spectrum

(100,0 MHz, CDCI 3 solution)

n ,

solvent

.. proton decoupled

I I

I

I

I

I

I

120

160

200

I

I

I

I

I

I

40

80

0

() (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

r ~P~.~~

Exchanges with 020 l--

. . . .

ppm

1.8

2,0

. . . .

0.8

0.6

ppm TMS

........

236

-1'---t

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

() (ppm)

Problem 148

3284

IR Spectrum (liquid film)

2000

3000

4000

1600

800

1200

V (ern")

100

Mass Spectrum

30

t-

80

.><

'a." Q)

60

No significant UV

Q)

Vl

'"

absorption above 220 nm

.0

40 '0 20

56

*" .•U

1

80

40

I

M+"= 102 « 1%)

CSH14N 2

J

I

120

160 mle

I

I

I

13C NMR Spectrum (100.0 MHz, COCI 3 solution)

200

240

280

,.. , ". ·.-.. . . fTl'' ' I

I

I

I

lIIWoo""""'' ' ' ' ' ' ' _'-'

"'.~";"",,,,-,,,,,,

T

I

''''''''_

,

; i'

solvent proton decoupled

I

I I

I

I

I

200

I

I

I

I

120

160

I

I

I

40

80

0

o(ppm)

1H NMR Spectrum (400 MHz, COC1 3 solution) Exchanges with 02°

expansions

+

2.2

10

9

2.1

8

2.0

7

ppm

0.9

6

5

ppm

0.8

4

TMS

3

2

1

o

o(ppm) 237

Problem 149

IRSpectrum (liquid film)

1718

1600 2000 V (em")

3000

4000 100

1200

0.0

800

Mass Spectrum

105

0.5

III

... Ul

91

1.0

212

'0

UV spectrum

...

J:J

M+"

J:J

40

\,.

o Ul

c-

60

s

...c €

80 ""... III

0.466 mg 110 mls a path length: 0.2 cm !2 path length: 2.0cm

77

~

20

II

,I

,1"1.

160

120

80

40

solvent: ethanol

I,

I

200

C14H1202 240

1.5

280

250

200

m/e I

13 C

I

I

I

I

NMR spectr=-u L ~ J Resolves into

I

I

I

300

A(nm)

I

350

I

two signals at higher field

(50.0 MHz, CDCI 3 solution) I

134

DEPT

1~O

I

ppm - - - - - -.........

CH2~ CH 3t CHt

, I III J

"----------r---------

Resolves into two signals at higher field

~

,3. proton decoupled I

II

130 PO";

IlR~

1

I

I

I

I

solvent

I

I

I

'--

_

I

I

80

160.

200

•

I

I

40

1H NMR Spectrum (200 MHz, CDCI 3 solution)

(

TMS

-

-

_ _ _ _- - - - J

10

238

9

L-J \."--

8

7

J ...._ - - - " -

6

5

J\-.

4

3

2

1

o

o(ppm)

Problem 150

IR Spectrum (CHCI 3 solution)

1700

3000

4000

2000

1600

1200

800

0.0

V (ern")

100

Mass Spectrum

105

80

~

60

.,

l'll Q)

a. Q)

l'll J:l

40

'0

M+"

77

~.

20

lI

UV spectrum

1.0

226

0.806 mg 110 mls path length: 0.2 cm

91

1,1

J

.I

40

80

solvent: ethanol

II

120

160

200

C15H1402 240

1.5

280

200

250

mle

300

350

A. (nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

TMS

off-resonance decoupled

proton decoupled

200

160

80

120

o

40

1H NMR Spectrum

TMS

(100 MHz, CDCI 3 solution)

10

9

0 (ppm)

8

7

6

5

4

3

2

1

o o(ppm) 239

Problem 151

IR Spectrum 1762

(CHCI 3 solution)

2000 1600 V (ern")

3000

4000 100 80 60

1200

Mass Spectrum

118

91

800

0.0

0.5

III

o

c:

.:.t.

\.

€ 0

(I)

.0
(I)


40 '0

1.0

108

;;R.

20 IL

1.

.I .

40

1

1..

80

UV spectrum

3.141 mg 110 mls path length: 1.00 cm

M+' 226

C15H1402

120

160

200

240

solvent: hexane

1.5

280

200

250

m/e

300

A. (nm)

350

13C NMR Spectrum (20.0 MHz, CDC'3 solution)

off-resonance decoupled

TMS solvent

proton decoupled

120

160

200

80

o

40

3 (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

10

240

9

8

7

6

5

4

3

2

1

o

3 (ppm)

Problem 152

IR Spectrum (liquid film)

3000

4000

2000

1S00

1200

800

V (cm'") 100 80

Mass Spectrum

277

\

..

-'"

to

Q)

C.

SO

Q)

'"

to

242

.0

40 '0

M+" = 310-322 «

1%)

170

~

20 C aH 4CI s 80

40

120

I

I

I

1S0 m/e

I

200

I

240

I

280

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

j DEPT

CH 2 , CH 3t CHt

solvent

proton decoupled I

I I

I

200 1H

I

11

I I

I

160

I I

I

120

80

I

40

0

3 (ppm)

NMR Spectrum

(200 MHz. CDCI 3 solution)

J expansion

I-'---

-

I

I

8.5

8.0

ppm

'-----' '----' I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

3 (ppm) 241

Problem 153

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

V (ern")

100 80 60

Mass Spectrum

119

f-

UV Spectrum

"'.,
Amax 246 nm Amax 273 nm

.,

0-

'"
.c

40 '0 20

*-

(109101':

3.7) "

(109101':

2.6)

solvent: ethanol

J

I

80

40

160 m/e

200

240

280

I

I

I

,

I

I

I

I

120

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI3 solution, 360 K)

DEPT

CH 2 • CH 3

+ CH +

I r

-L ,

,

138.5 proton decoupled I

I

138.0 PPM

solvent

I

I

120

160

1-

I

I

I

I

40

80

I

0

o(ppm)

~

at 360 K

r,

,

, ,

3.4 3.5

I

I

I I

200 1H NMR Spectrum (400 MHz, CDCI 3 solution)

~

I I

I

ppm

1.2 1.1 ppm

3.0

1.0

at 298 K

10

242

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 154

exchanges with 0 2 0

I

ppm

7.5

10

9

8

7

6

5

4'

3

2

1

o

o(ppm) 243

Problem 155

IR Spectrum

1770

1700

(CHCI3 solution)

2000

3000

4000

1600

1200

0.0

800

V (ern")

100

Mass Spectrum

120

0.5

43

80

.,,;

\c

'a." Q)

60

138

Q)

UV spectrum

rJl

'"

1.0

..0

40 a


M+"

I

20

III, • .III

180

160

120

solvent: methanol

CgH a0 4

III

80

40

0.458 mg /10 mls a path length: 1.00 cm !l path length: 0.2 cm

200

240

1.5

280

200

250

m/e I

I

I

I

I

I

I

I

I

I

I

300

A(nm)

350

I

13C NMR Spectrum (50.0 MHz, CDC'3 solution)

DEPT

CH 2

t CH

3t

U

CHt

I

~sion I

I

I

solvent

I

170

175

.

165 ppm

I

proton decoupled I

I

I

II I

I

I

160

200

I

120

1H NMR Spectrum

I

I

I

80

I

o

40

0 (ppm)

expansion with resolution enhancement

(200 MHz, CDCI 3 solution)

broad resonance exchanges with 0 20

8.2

7.8

7.4

ppm

TMS

10

244

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 156

IR Spectrum (CHCI3 solution)

4000

2000 1600 V (cm'")

3000

1200

100

0.0

800

Mass Spectrum

80

0.5

..l<

-e0

Q)

0-

60

Q)

(/)

90

(/)

20

*"


M+'

..Q

'0

UV spectrum

..Q


40

Q)

o c



1.0

249/251/253

0.245 mg 110 mls path length: 1.00 cm

91

II" J I~I 40

.. 80

160

120

solvent: ethanol

C 6H SNBr2

j,j

200

240

1.5

280

200

250

m/e I

I

I

I

I

I

I

I

I

I

300

A(nm)

I

350

I

13C NMR Spectrum (20.0 MHz, COCI 3 solution)

1 off-resonance decoupled

,i

I

proton decoupled

I

I

I

I

i

I

200

f

t

TMS

solvent

I

III I

I

I

160

I

I

I

80

120

I

I

40

I

0

o(ppm)

lH NMR Spectrum TMS

(100 MHz, COCI 3 solution)

exchanges with 0 20

10

9

8

7

6

5

4

3

2

1

o o(ppm) 245

Problem 157

IR Spectrum (KBrdisc)

2000

3000

4000

1600

1200

800

0.0

V (cm'")

100 80 60

Mass Spectrum

191

57

"''C""D 0.

20

CD

g

.e~

CD

UV spectrum

..c

''""

..c

40

0.5

1.0 '"

M+'

'0

1.208mg 110 mls path length: 0.5 cm solvent: ethanol

206

<;e

111

'oJ

40

II

,I

.1

120

80

,C 14H 22O

I

160

200

240

280

1.5 L.J..- .................o.....L....o.-~"""-L......r..."""-'-'-..u 200 250 300 350

A(nm)

m/e

13e NMR Spectrum (20.0 MHz. COCI3 solution)

off-resonance decoupled

TMS

proton decoupled

160

200 1H

120

o

40

80

0 (ppm)

NMR Spectrum

(100 MHz. COCI3 solution) expansion I

I

If-

25 Hz

)

~

~ A

246

r

TMS

exchanges with 0 20

---'

j

A

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o (ppm)

Problem 158

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

261/263/265 182/184

80 7;i Q)

a-

60

5l

1l

M+'

197/199

40 '0

276/278/280

20

80

40

160 m/e

I

I

I

I

I

120

240

200

I

J

280

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

I DEPT /

I

CH 2 , CH 3t CHt

I

l

I

proton decoupled

200

solvent

I

I

160

BI

120

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution)

_J

expansion

I

7.0 ppm

7.5

expansions

I

3.0

10

i.

9

8

7

6

5

4

3

2

1

o

o(ppm) 24'

Problem 159

1689

IR Spectrum (KBrdisc)

2000

3000

4000

1600

1200

800

V (ern")

100

Mass Spectrum

104 227/229

80

-""

60

Q)

'a." Q)

M+"

en

242/244

'"

163

.0

40

(;

*-

20

120

80

40

160

200

240

280

m/e

13C NMR Spectrum

one signal even at high field

~

(50.0 MHz. CDCI 3 solution)

_ _tiJ_-----'J_ Resolves into two signals at higher field

~

--~'-------''---solvent

proton decoupled

160

200

1

1H NMR Spectrum (200 MH,. CDCI, 001"",,0)

120

o

40

80

0 (ppm)

I

II

~ULJL expansions

exchanges with DzO

~

I

I

I

8.2

8.0

7.8

I

7.6 ppm I

I

1.4

1.3

I

1.2 ppm

I

11.0

10.0

TMS 3.1

10

248

9

8

7

6

3.0

2.9 ppm

5

4

3

2

1

o

o (ppm)

Problem 160

IR Spectrum

1695

(CHCI3 solution)

2000 1600 V (crn'")

3000

4000 100 80

1200

800

Mass Spectrum

149

0.0

0.5

-e'o"

'" c4l

60 40 20

eo

c:

.><

(/)

4l

UV spectrum

..0

(/)

..0

M+'

'0

150

'"

0~

Iii JI

I ~j

40

I.

80

1.0 '"

T 120

Ca H 603 160

200

240

0.298 mg 110 mls path length: 0.5 cm solvent: ethanol

1.5

280

200

250

m/e

300

350

A. (nm)

13C NMR Spectrum (20.0 MHz, CDC13 solution)

solvent

off-resonance decoupled

,

TMS

solvent

proton decoupled

I

200 1H

I

160

1

III

I 120

40

80

0

o(ppm) TMS

NMR Spectrum

(100 MHz, CDCI 3 solution)

J

--»

expansion

6.80 ppm

7.70 ppm

10

9

8

7

6

5

4

3

2

1

0

o(ppm) 249

Problem 161

IR Spectrum

1526

1353

(liquid film)

2000

3000

4000

1600

1200

800

V (cm'")

100 80

Mass Spectrum

79 134

-'" CIl

\i


60

VJ

CIl .0

40 a

*'

20

M+'

1

151

J~'

40

J

,J.

.

I 120

80

CaH gN02

160

200

240

280

m/e

13C NMR Spectrum

__Ul"""-----_l

(50.0 MHz, CDCI 3 solution)

d

DEPT

CH2 , CH 3+ CH+

.proton decoupled

I

I I

160

200

solvent

III

120

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz. CDCI 3 solution)

-

Resolves into two signals of equal intensity et higher field

expansion

____I 10

250

9

8

I

7.0

ppm

TMS

7

6

5

4

3

2

1

o

o(ppm)

Problem 162

1

i

I r I

r I

IR Spectrum (KBr disc)

4000

2000 1600 V (cm'")

3000

100 80

1200

800

Mass Spectrum

159

\r

.><

'"c, Q>

60

Q>

'"

M+'

'0

194/196

'"

.0

40

>!i!.

0"

I

20 40

80

120

160

200

240

280

m/e

t 13C

NMR Spectrum

(50.0 MHz, CDCI3 solution) expansion I

LL

ppm

135 Resolves into

~~ I

expansion

200

160

120

I

135

130

80

ppm

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI3 solution)

TMS I

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 251

Problem 163

IR Spectrum (KBr disc)

4000

2000

3000

1600

1200

800

V (cm'")

100 80

Mass Spectrum M+"

-""

11l

Ql

60

c.

195-201

Ql (J)

11l

.0

40

'0 ;f!.

20 C S H 4CI3N

40

160

120

80

200

240

280

m/e I

I

13C

I

I

I

NMR Spectrum

CH 2 •

-

CH 3t

I

I

I

I

I

I

I

U

(50.0 MHz, COCI 3 solution)

DEPT

I

I

CHt

solvent

;'

I

proton decoupled I

I

I

I

160

200 1H

I

I

I

jI I

120

I

I

80

I

40

0

() (ppm)

NMR Spectrum

(200 MHz, COCI 3 solution)

exchanges with 0 20

~

r---

l-----"

TMS

1

""

252

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

s (ppm)

Problem 164

IR Spectrum

.(

.

(CHCI3 solution)

2000 1600 V (crn'")

3000

4000

,.-

1200

--,0.0 -'

100 80

800

Mass Spectrum .><:

I- 0~

60

0.5

248

o~ .

\r

UV spectrum

.c

390

40 "5

sc

~'"en

M+"

~ .c '"

~

1.0

'"

0.390 mg I 10 mls path length: 1.00 cm

233

20

'-

solvent: dioxan

375

I. 40

80

.-

120 160 200 240 280 320 360 400

250

m/e

13c NMR Spectrum (20.0 MHz, CD 3SOCD 3 solution)

300

350

A. (nm)

solvent

C-H C

C-H C TMS

proton decoupled

200

160

120

80

o

40

0 (ppm)

lH NMR Spectrum (100 MHz, CDCI 3 solution) 6H

TMS

lH

residual CHCI 3 in solvent

~

lH

1

I I

I

I

I

I

I

I

I

I

I

I

l

l

10

9

8

7

6

5

4

3

2

1

I

0

s (ppm)

t !

f

253

Problem 165

IR Spectrum 1685

(liquid film)

1600

2000

3000

4000

1200

800

V (ern")

100t-

Mass Spectrum

68

UV Spectrum

80 t-.><<'ll 60

'\

/\,max 225nm (I0910E 3.9)

CIl 0CIl Ul

'" '0

.0

40 20

\!

solvent: methanol

M+"= 96

*-

~

l

,J'

""I " " " ' , "

40

80

CSHSO 160

120

200

240

2S0

m/e

13C NMR Spectrum (100.0 MHz, CDCI3 solution)

proton decoupled

solvent

•

I

~

160

200

o a(ppm)

40

80

120

1H NMR Spectrum (400 MHz. CDCI3 solution)

,

,

6.9

2.4

,

, 1.9

2.2 ppm

1.8 ppm

TMS

10

254

9

8

7

6

5

4

3

2

1

o

a (ppm)

• I '.. '~

Problem 166 3457

IR Spectrum

1671

(CHC'3 solution)

2000

3000

4000

1600

800

1200

V (cm'")

100

Mass Spectrum

UV Spectrum \j

80

.><

Amax 263 nm Amax 305 nm

'"

Ql C>Ql
60

'"

J:l

40 '0
(109101:: 2.1 )

solvent:

20 III

hexane

I

,I

40

120

80

160 m/e

200

280

240

expa~

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

.I

(109101:: 3.9)

proton decoupled

I

I

30

20 ppm

40

30

20 ppm

solvent

160

200

40

120

l o

40

80

0 (ppm)

expansion

1H NMR Spectrum (400 MHz. CDC'3 solution) expansion

Exchanges withD20

2.0

2.5

t i

o

o

6.4

6.2

PPM

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 255

Problem 167

IR Spectrum

1666

(liquid film)

2000

3000

4000

1600

800

1200

V (ern") 100 80

Mass Spectrum

109 """-

UV Spectrum

81

ttl
Amax 234 nm

C.

60

~,

(109108

4.1)


III

43

ttl

.c

solvent: ethanol

40 '0

M+"= 124

~

20

I

I

80

40

CaH 120

,I

160

120

240

200

280

m/e

expansion~

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

proton decoupled

160

200 1H

120

25

20 ppm

25

20 ppm

40

80

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI3 solution)

A 6.80

/"'oJ

~p"m", ,

6.75 ppm

2.2

,

.1

I

~ ,

2.0 ppm

,

1.4 ppm

1.5

TMS

10

256

9

8

7

6

5

4

3

2

1

o o(ppm)

Problem 168 .(.

\;

UV spectrum 10.8 mg 1100 mls path length: 0.1 cm solvent: cyclohexane

250

300

A (nm)

350

13C NMR Spectrum (100 MHz, CDCI 3 solution)

DEPT

CH2 , CH3t CHt

,

solvent proton decoupled

W

I 160

200 1H

40

80

120

0

o(ppm)

NMR Spectrum

(400 MHz, CDCI 3 solution)

with irradiation

at 05.95

----

'--

expansion r!;'

!

I

I

6.0

A

I

I

5.9

ppm

I

----~

S

TMS

expansion

I

I

J

2.0

1.9

1.8

~

I

ppm

-

-

A

i

,,;

-11- 2.75 Hz

-11-2.55 Hz

1,. ~i

I

10

9

8

7

6

I

I

5

4

3

2

1

o o(ppm)

v.

257

Problem 169

IR Spectrum (liquid film)

1200

1600

2000

3000

4000

800

V (ern") 100 80 60

Mass Spectrum

91

"'ill"

UV Spectrum

Amax 260 nm Amax 266 nm

III

M+"= 118

0. ill

Ul

III .0

40

'0

20

*'

Amax 272 nm 200

160

120

80

40

C g H 1Q

.1.

I ·d

240

(109101':

2.9)

(109101':

3.1)

(109101':

3.1 )

\)

solvent: methanol

280

m/e

13C

,

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, CDCI 3 solution)

DEPT

,i

CH 2

1CH

3t

1

CHt

~

proton decoupled

I

I

I

I

I

1 I

I

I

120

160

200

solvent

•

I

I

U I

40

80

I

0

o(ppm) :..,.

1H

NMR Spectrum

(400 MHz, CDC'3 solution) expansion

~

expansion

expansion

~

j 7.4

7.3

ppm

3.2

3.0

2.3

ppm

2.2

ppm TMS

10

258

9

8

7

6

5

4

3

2

1

o o(ppm)

<

Problem 170

IR Spectrum (liquid film)

1708

2000 1600 V (ern")

3000

4000

1200

100

0.0

800

Mass Spectrum

80

145

.><

'"

Ql 0Ql

60

II>

o

\i

C

-e0'"

M+' 160

U)

UV spectrum

J:J

U)

1.0 '"

'"

J:J

40

0.5

'0

0.364 mg 110 mls path length: 0.5 cm

~

20 I.

,I

40

,I

J,

80

.,1

C 11 H120

U 120

160

240

200

solvent: cyclohexane

1.5

280

200

250

m/e

300

350

A(nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution) ,

f

135

130

i

125 ppm

off-resonance decoupled

i i i

135

proton decoupled

200

160

130

125 ppm

80

120

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

exchanges after prolonged treatment with 0 20 containing a trace of DCI or NaOD

,

--

It---

TMS

----'

j

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 259

Problem 171

IR Spectrum

1719

(CCI4 Solution)

1600 2000 V (ern")

3000

4000 100 80

800

Mass Spectrum

M+" = 132

104

1200

UV Spectrum

x

Amax Amax

III

Q)

60

0. Q)

<Jl

III .0

40

'0 ;f!.

20 II

40

=243nm

(109108

4.1)\1

= 291 nm

(109108

3.4)

solvent: ethanol

III~

C9HaO

I

80

160

120

200

240

280

m/e

10

260

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 172

IR Spectrum

1751

(CHCI3 solution)

SOO

1200

1600 2000 V (ern")

3000

4000 100

Mass

Spectrum

UV Spectrum

104

SO "'CIl"

Amax 26S nm Amax 275 nm

Q)

60

eQ)

til

CIl

.&J

40

'0

(109101';

3.1)

(109101';

3.1)

M+"=132

;ft

20 II

~I

40

l

I

120

SO

solvent: ethanol

CgHSO 160

200

240

2S0

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDC'3 solution)

proton decoupled

I

I

I

I

I

J

160

200

solvent

I I

I

120

I

40

80

I

o

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

TMS

I I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 26:

Problem 173

1683

IR Spectrum (liquid film)

2000 1600 V (crn'")

3000

4000

1200

118

100 80

800

Mass Spectrum

UV Spectrum

M+"= 146

"'Cl>" III

Amax 249 nm Amax 292 nm

0. Cl>

60

l/)

III .0

a

40

~

4.1)

(log10'"

3.3)

IV

solvent: ethanol

20

I

I

120

80

40

I

160 m/e

200

240

DEPT CH2~

I

I

I

ill

ppm

130

I

,

i

CH 3t CHt

d.","P''''

280

,

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

proton

(log 10 '"

125

I II

J

ill uJ ~ ppm

I

.

130

I

160

200

,

solvent

125 I ..

I

120

40

80

1H NMR Spectrum (400 MHz, CDCI 3 solution)

0

8 (ppm)

expansion

expansion

, 8.0

10

262

i

ppm

7.5

9

2.5

8

7

6

5

2.0 ppm

4

TMS

3

2

1

o

8 (ppm)

Problem 174

IR Spectrum

1716

(liquid film)

2000

3000

4000

1200

1600

800

V (crn'") 100

Mass Spectrum

104

UV Spectrum \i

80 60

.><

'0.C"Il

M+'= 146

CIl

III

'"

.0

40

'0 ~

20 I

J I j,

,1

II

(l091OE 3.1)

Amax 294 nm

(l091OE 1.9)

(1091OE 3.0)

C1QH1QO

I

solvent: ethanol

120

80

40

II

Amax 265 nm Amax 272 nm

160

200

240

I

I

280

m/e I

I

13C

I

I

I

(100.0 MHz, CDCI 3 solution)

129

DEPT

I

I

I

128

I

expansion

~

proton decoupled

II

I

I

I

I

I

160

200 1H

I

ppm

CH2 , CH 3t CHt

.-J

I

~pansion

NMR Spectrum

~ 128

129

ppm

solvent

,---J I

I

120

UJ I

I

I

I

I

40

80

o(ppm)

0

NMR Spectrum

(400 MHz, CDCI 3 solution)

~

expansion

l

{

I

3.2

-

I

I

I

7.3

7.2

expansion

expansion

ppm

JL

I

I

3.0

ppm

~

-

~

..--

---

I

I

2.6

2.5

TMS

~

---"

I

ppm

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 263

Problem 175

IR Spectrum (CHCI3 solution)

1600 2000 V (crn'")

3000

4000 100 80

40

800

Mass Spectrum

165

0.0

0.5

'0."

CD

u

c

M+"

.;,<

€'" 0

lBO

CD

60

1200

III

.c

CD III

1.0 '"

.c'"

'0

;ft

20 'JJ,

40

80

1.5

160

120

0.194 mg 110 mls path length: 0.5 cm solvent: cyclohexane

C 14 H12

~I

UV spectrum

200

240

280

200

250

mle

300

350

A. (nm)

13C NMR Spectrum (100 MHz, CDCI 3 solution)

solvent

_____'-----'----'w'-__--'---

_

proton decoupled

160

200

120

80

o

40

0 (ppm) TMS

lH NMR Spectrum (100 MHz. CDCI 3 solution) >--

-.!

)1 ~

264

~

1

U~

'-

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

s (ppm)

Problem 176

IR Spectrum

1715

(KBr disc)

2000

3000

4000

1600

1200

800

V (ern") Mass Spectrum

100

\i

80 r->
Amax 265 nm Amax 330 nm

M+"= 180

Ql

a.

60

UV Spectrum

Ql

en

co

.c

152

'0

40


(109108 4.5) (109108 4.2)

solvent: ethanol

20 .I

I

80

40

C13H 8O

120

160

200

240

280

mle

13e

NMR Spectrum

expansion

(100.0 MHz, CDCI 3 SOIU~

i i i

DEPT CH 1 CH 2

135

125

ppm

CHt

-"-..I-J....I...

_

3t

proton decoupled

UII i

i

135

125

solvent

1

I

ppm

I

160

200 1H

o

40

80

120

expansion

NMR Spectrum

(400 MHz, CDaCN solution)

I,' "

7.65

7.60

7.55

ppm

M 7.35

ppm

7.30

solvent residual

residual H 2 0 in solvent -

10

9

0 (ppm)

8

7

6

5

4

3

2

TMS

1

o

o(ppm) 26:

Problem 177

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (cm'") 100

45

Mass Spectrum

43

80

x

29

co Q)

\i

Co

60

No significant UV

Q)

sn

co

absorption above 220 nm

.i:J

40 '0

M+" = 132 « 1%)

~

89

20

.. 87

1

1

80

40

I

I

I

C SH 120 3

117 131

I

120

160 m/e

I

I

200

240

I

280

I

I

I

I

I

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

III

off-resonance decoupled

I

TMS

solvent

proton decoupled

I

III I .

I

I

I

160

200

1H

I

I

I

I

I

I

I

o

40

80

120

I

0 (ppm)

NMR Spectrum

(100 MHz, CDC'3 solution)

J TMS

~

266

I

I

10

9

1

I

I

I

I

I

I

I

I

8

7

6

5

4

3

2

1

;

0

s (ppm)

Problem 178

13C NMR Spectrum (20.0 MHz. CDCI 3 solution)

I

H-C-H I

C

TMS C solvent

proton decoupled

ill

200

160

80

120

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o o(ppm) 267

Problem 179

1800

IR Spectrum (KBr disc)

1765

2000

3000

4000

1600

1200

800

V (ern") 100 80

Mass Spectrum

56 ~

70


60

uv

No significant


l/l


absorption above 220 nm

40 '0 ;/!.

20

1 120

80

40

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDC'3 solution)

solvent

•I

proton decoupled

I I I

I

I

120

160

200

I I

40

80

0

s (ppm)

lH NMR Spectrum (400 MHz, CDCI 3 solution)

expansion

L ,

2.8

expansion

~

i

2.7

ppm

,

,

1.9

1.8

ppm ,.-

268

I

I

I

I

I

I

I

10

9

8

7

6

5

4

-

r-

TMS ---J

-

I

I

I

I

3

2

1

I

0

s (ppm)

Problem 180

3405

1721

2000

3000

4000

800

1200

1600

V (ern") 1001-

Mass Spectrum

43

\/

80

oX

'"c.

Q>

60

71

Q>

No significant UV

'" I- .0 '"

absorption above 220 nm

40 '0

:>e 0 ..

M+"=130«1%)

20

~II I,

1..11

IJ.

120

80

40

C6H 1003

,I

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

DEPT

CH 2

f

I

I

13C NMR Spectrum (100.0 MHz, COCI3 solution)

I

I

CH 3t CHt

solvent proton decoupled

f

I

I

I

1

200 1H

160

o

40

80

120

0 (ppm)

NMR Spectrum

(400 MHz, COCI 3 solution) expansions

, 4.4

, 4.2 ppm

2.5

1.8

, 1.6 ppm

Exchanges with 020

f TMS

10

9

8

7

6

5

4

3

2

1

o o(ppm) 269

Problem 181 3207

IR Spectrum

1678

(KBrdisc)

2000

3000

4000

1600

1200

800

V (cm'")

100

55

Mass Spectrum

UV Spectrum

80 "'" 'a.C"Il 60 CIl lJl

'"

.0

40

Amax 230 nm

(10910£

3.6) pH Y1

Amax 230 nm

(10910£

4.4) pH 13

'0

solvent: water

M+"= 155


20 40

120

80

160

200

240

280

m/e I

I

I

I

I

I

I

I

T

I

expan~

13C NMR Spectrum (100.0 MHz, COCI3 solution)

I

ppm

34

35

I

expansion

L 35

solvent

ppm

34

proton decoupled

• I I

I

I

I

I

I

120

160

200

I

I

I

llu I

I

I

40

80

0

o(ppm)

1H NMR Spectrum (400 MHz, COCI3 solution) expansion

Exchanges with 020

2.6

ppm

2.4

2.5

2.0

ppm

1.5

TMS

~

10

270

9

8

7

6

5

4

3

2

-

1

0

s (ppm)

Problem 182

IR Spectrum (liquid film)

1200

2000 1600 V (crn'")

3000

4000

100

140

800

Mass Spectrum

I-

80 60

.><
56

a.

No significant UV

4l

l/l


40

absorption above 220 nm

(; ~ D

42 •

20

I,

M+"=

I

I

80

40

I

I

155

C10H 21N

I

120

160 m/e

200

240

280

I

I

I

I

I

I

I

T

I

T

13C NMR Spectrum (100.0 MHz, CDCI J solution)

I DEPT

CH 2 , CHJt CHt

,

1

solvent proton decoupled

I

I

200

I

I

I

I

160

I

I

I

I I

I

o

40

80

120

I

I

I

I

0 {ppm}

1H NMR Spectrum (400 MHz. CDCI 3 solution)

expansion

J 10

9

8

7

6

5

4

3

2

1

TMS

o

o{ppm} 271

Problem 183

IR Spectrum (KBr disc)

3249

2000 1600 V (cm'")

3000

4000

43

100 80

1200

800

Mass Spectrum

109

-"

'0-<"1l

60

<1l

UJ

'"

.0

40

'0

*"

20

127

5~ ,I 40

M+" = 142 « 1%)

I

80

120

200

160

240

280

m/e

13C NMR Spectrum (100.0 MHz, COCI 3 solution)

solvent proton decoupled

• 120

160

200

80

o a (ppm)

40

1H NMR Spectrum (400 MHz, COCI 3 solution)

Exchanges with 020

-

272

I

I

I

10

9

8

--

TMS

........

I

I

I

I

I

I

I

I

7

6

5

4

3

2

1

I

0

a (ppm)

Problem 184

IR Spectrum

1682

(liquid film)

2000

3000

4000

1600

1200

800

V (em")

100 80

66

Mass Spectrum

UV Spectrum !Ii

.,'" ., .c ''"" '0

-""

I0910c

Co

60 40

>

4.0

M+·


~

20

jl

94

Il

.II

40

C 6H6O

120

80

160

240

200

280

mle I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI3 solution)

I DEPT

CHz' CHJ CH+

J

,'01'" d=",,:J I

I

I

200

I

I 120

I

160

Lr.

solvent

j"

4

I

I

I

I

80

I

I

40

0

o(ppm)

1H NMR Spectrum (200 MHz, CDCI3 solution)

v-----

I---

~

S-

1-

----J

-

a

TMS

1

I

I

I

I

I

I

,

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm) 273

Problem 185

2100

IR Spectrum 3275

1630

(liquid film)

2000

3000

4000

1600

1200

0.0

800

V (crn'") 100

Mass Spectrum

80

~

60

3l

0.5

CD

c.

UV spectrum

III

*-

20

0.182 mg 110 mls path length: 0.5 cm

1.0

.Q

40 '0

solvent: dioxan

I, ..I

L-~..l..-..~""""~""""'''''''''''""""""",_''''''--'''''''''''",,,,"""",_''''''--'''''''''''''''''''''''''''''''''''''''''''''''o-L-'''''''''''l......o.....J 1.5 "'"""-'--'120 160 200 240 280 80 200 40 m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

250

........ 350

300

A(nm)

expansion I

80

I

80

160

200

I

70 ppm

i

70 ppm

120

80

o

40

0 (ppm)

lH NMR Spectrum (200 MHz. CDCI 3 solution) expansions with resolution enhancement

274

20 Hz

I

I

I

6.4

4.45

3.1

I

3.0 ppm

~

I

I

I

I

-r I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

J

TMS

I

I

I

o

o(ppm)

Problem 186 2240

3370

IR Spectrum (liquid film)

2000 1600 V (crn'")

3000

4000

1200

100

0.0

800

Mass Spectrum 43

~

80

8

0.5

c:

102

Q)

'"

€

0.

~

60

'"

.0

40

~

UV spectrum

'"

0.434 mg 110 mls path length: 0.2 cm

.0

1.0

M+' = 174 « 1%)

156

'0 o~ "

solvent: methanol

20

C 12 H 14 0 40

80

120

160

200

1.5

280

240

200

250

m/e

13C

350

300

A. (nm)

NMR Spectrum

(20.0MHz, COC'3 solution)

2 xC-H

C-H

- - Resolves into two signals at higher field I

H-C-H I

solvent

-CH -CH

3

3

C C

I

proton decoupled

200

C

I

120

160

C

1

TMS

l

l III 40

80

0

lH NMR Spectrum

o(ppm) TMS

(100 MHz, COCI 3 solution)

~

-------

I

10

I

9

lH exchanges with 0 20

-

-----

)LJk~ ~ ....._ _- - J

~

I

I

I

I

I

I

I

I

8

7

6

5

4

3

2

1

I

o

o(ppm) 275

Problem 187

IR Spectrum (liquid film)

2000

3000

4000

1600

100 80 60

1200

800

V (cm'") UV Spectrum

Mass Spectrum M+-

x

140

'"

109 10 1':


> 4.0

III

'"

.0

40 '15 cf'.

20 1

,j

{1.l1

40

,1111

80

j

C 11 Ha 160

120

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

two resolved signals --- at higher field

expansion

two resolved signals --- at higher field

I

I

70 ppm

solvent

proton decoupled

160

200

120

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

J

TMS

I

\

10

276

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 188 3332 3267

IR Spectrum

1713

(KBr disc)

2000

3000

4000

1200

1600

800

V (crn'")

100

Mass Spectrum

168

UV Spectrum \i

80

~

60

:g

109101> > 4.0

Q)

c-

'"

J:J

40 '0

140

~.

20

l 120

80

40

200

160

240

280

role I

I

I

I

I

I.

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CHzt CH 3t CHt

U

solvent

proton decoupled

I I

I

I

I

I

I

120

160

200 1H

I

I

I

40

80

0

o(ppm)

NMR Spectrum

(400 MHz. CDCI 3 solution)

Exchanges with 020

I-

j

~

I~

TMS ---'

-..J'

I

" I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o (ppm) 277

Problem 189

I If

IR Spectrum (liquid film)

1600 2000 V (ern")

3000

4000 100

1200

Mass Spectrum

121/123

80

.x:

800

41

III

"

Q)

Co

60

Ul

40

'0

No significant UV

Q)

III

absorption above 220 nm

..c ~

M+" 200/202/204

20 I

II

40

C 3H S Br2

,I,

160

120

80

200

240

280

I

I

I

m/e I

I

I

I

I

T

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

_ _~lL,solvent

proton decoupled

120

160

200

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI3 solution)

expansion

expansion expansion "'I' "" 'I 1.9 1.8

1' ppm

TMS ""1""""'1" "'" I' 4.3 4.2 ppm

10

278

9

""'"

'I

'

" I"

3.8

8

3.6

7

6

ppm

5

4

3

2

1

o o(ppm)

Problem 190

IR Spectrum

3433

1713

(KBrdisc)

1200

2000 1600 V (ern")

3000

4000

76

100 80

Mass Spectrum

58

~

1'0 CD Co CD

60

800

No significant UV

74

en

1'0

.c

40

absorption above 220 nm

15 cf!..

20 IIII

I

80

40

I

I

120

160 m/e

I

I

I

200

240

280

I

I

I

I

T

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

DEPT

CH 2

1CH

3t

CHt

solvent

L

proton decoupled I

I

I

I

200

I

I

I

120

160

1H NMR Spectrum

o

40

80

0 (ppm)

expansions

(400 MHz, CDCI 3 solution)

4.2

4.1 ppm

2.2

1.0

2.1 ppm

0.9 ppm

Note: very broad signal from about 8 ppm to 5.5 ppm exchanges with 0 20

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 279

Problem 191

IR Spectrum 3350

(liquid film)

1600

2000

3000

4000

1200

aoo

V (ern")

1001-

Mass Spectrum 61

ao

43

.:><

'a."

\I

(I)

60

No significant UV

(I)

V>

40

'" '0

20

*'

absorption above 220 nm

..0

,~

M+o= 92 «

C3Ha0 3 160

120

ao

40

1%)

200

240

2aO

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz. 020 solution)

I

proton decoupled

I

I

I

I

I

120

160

200

I

I

o

40

80

3 (ppm)

1H NMR Spectrum (400 MHz. 020 solution) H20 and HOO in solvent expansion

ppm

10

280

9

8

7

6

5

4

3

2

1

o

3 (ppm)

Problem 192

IR Spectrum

3305

(liquid film)

2000

3000

4000

1600

1200

800

V (cm'")

100 80

45

Mass Spectrum

.x



C.

60

No significant UV


CI)


59

..c

absorption above 220 nm

40 '0 :;,'!. o.

M+" =

20

JJ

I,

74 (< 1%)

LI

40

80

120

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

.u_Uuk

proton coupled

lU

solvent m

•

proton decoupled

200

160

120

80

40

0

() (ppm)

1H NMR Spectrum (200 MHz, CDC'3 solution)

exchanges with D20

expansion

2.5

3.5

10

9

8

1.5

7

6

ppm

5

4

3

2

1

o

() (ppm)

281

Problem 193

IR Spectrum

1033

(KBr disc)

2000

3000

4000

1600

1200

800

V (crn'")

100

Mass Spectrum

91

80

.x:

60

III

til III

o, VI

til .0

40 20

'0

*-

123

I

120

80

40

I

160

200

240

280

mle I

I

J

13C

NMR Spectrum

(100.0 MH>, CDCI,

~.,;ooLj

t CHJ

I

I

I

T

J

I

I

_L

DEPT CH2

I

I

J

expansion

, 129 ppm

130

CHt

note

proton, decoupled

I

lJl

'"

solvent

,

t

129 ppm

130

I I

I

I

I

I

I

160

200

I

120

I

I

I

40

80

0

() (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution) expansion

~ 4,0

10

282

9

8

7

6

5

4

3

3.85

2

ppm

1

TMS

o

() (ppm)

Problem 194

r IR Spectrum 1675

(CHCI3 solution)

3000

4000

1580

2000 1600 V (cm'")

1200

100

0.0

800

Mass Spectrum

80

-'"

B

c:

'Co"

€'"

M+'

Ql

60

0.5

135

0

180

Ql III

III

.0

'"

.0

1.0

40 '0

ro

UVspectrum

0.390 mg 110 mls path length: 0.2 cm

*"

20

CgH aS0 2 120

80

40

160

200

240

solvent: ethanol

1.5

280

200

250

m/e 13C NMR Spectrum

300

350

A(nm)

iI

(20.0 MHz, CDC'3 SOIUlIon)j

JL

~

off-resonance decoupled

expansion

solvent

TMS I

130 ppm

proton decoupled

160

200

120

40

80

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution) TMS

° """~ with O2

Ir-

~

i

10.9

I ,----J

\.l I

I

10

9

8

,

I

I

I

I

I

I

7

6

5

4

3

2

1

I

0

o(ppm) 283

Problem 195

IR Spectrum

1350

(CHCI3 solution)

1176

100

1200

2000 1600 V (ern")

3000

4000

91

80

0.0

800

Mass Spectrum

0.5

'"

M+'

al

c,

60

al

200

155

III

'"

1.0

40 '0

*'

~ II.

e'" s '"

.D

.D

20

B

c

.><

-

UV spectrum 7.260 mg 110 mls path length: 0.5 cm solvent: ethanol

172 J

40

u

80

l

CgH 120 3S

I

120

200

160 m/e

13C NMR Spectrum

240

280

1.5 ........~...................~.................,c.........'""--'.................. 200 250 300 350

A. (nm)

C-H

(20.0 MHz. CDCI 3 solution)

C-H

I

H-C-H I

C

solvent

C

proton decoupled i

120

160

200

o

40

80

,,(ppm)

1H NMR Spectrum (100 MHz. CDCI 3 solution)

TMS

10

284

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 196

IR Spectrum (nujol mull)

2000

3000

4000

1600

1200

800

0.0

V (ern")

100

Mass Spectrum

139 ~ CD c. ~

80 60

CD

lJ

C

-e'0" .c'"

M+"

'" '0

.c

40

0.5

154

91

1.0

'"

UV spectrum


2.068 mg 110 mls path length: 0.1 cm

20

solvent: ethanol

L-~

........&.-~L...o.....L...""""""_J......o..-'-""""""~J......o..-'-"""""'__"""""---'-"""""'~...L.....o.....J 1.5 L..l-.

40

80

120

160

200

240

280

"""'--

200

.......-

250

m/e

......

300

350

A(nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

off-resonance decoupled

solvent

TMS

proton decoupled

200

160

80

120

o

40

(5 (ppm)

1H NMR Spectrum (100 MHz. CDCI 3 solution)

TMS

~ I

I

1

10

9

8

J~

1

I

I

I

I

1

I

7

6

5

4

3

2

1

L

0 (5 (ppm)

285

Problem 197

IR Spectrum (nujol mull) 1315 1150

2000

3000

4000

1600

1200

0.0

800

V (ern")

100 80

.x

Q)

0.5

l'll

of o

o,

60

'"

Q)

..c

'l'll" ..c

UV spectrum

l'll

1.0

40 '0 20

Q)

o

c:

172

92

l'll

Mass Spectrum

M+'

156

*' II ,IL

.I,

160

120

80

40

solvent: ethanol

C 6H aS0 2N2

l

200

240

0.706 mg 110 mls path length: 0.1 cm

1.5

280

200

250

m/e I

13C

I

I

I

I

I

I

I

I

I

300

350

A(nm)

I

I

NMR Spectrum

(15.0 MHz. o"O/OCI solution) C-H

C-H

C C proton decoupled I

I

II I

I

I

I

I

120

160

200

80

o s (ppm)

40

1H NMR Spectrum

TMS

(100 MHz, C0 3COC03 solution)

exchanges slowly with 0 20 solvent

10

286

9

8

7

6

5

4

3

2

1

~

o

(ppm)

Problem 198

r IR Spectrum (liquid film) 1320

3000

4000

2000

1135

1200

1600

800

V (cm'")

100

Mass Spectrum 75

80 ""co Q)

No significant UV

c,

60

Q) (J>

absorption above 220 nm

'"

.0

40

'0 ~ o.

M+" = 118 «

20

40

80

120

1%)

160

200

240

280

m/e I

I

13C

I

I

I

I

I

I

I

I

I

I

.

,

I

I

I

NMR Spectrum

(50.0 MHz, CDCI3 solution)

II

proton coupled

I

solvent proton decoupled I

I

I

I

I

I

160

200

I

120

I

•

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI3 solution)

expansion

I

I

I

7.0

6.6

6.2

I

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 287

Problem 199

IR Spectrum (liquid film)

2000 1600 V (ern")

3000

4000

1200

100

0.0

800

Mass Spectrum 139

80 60

0.5

.>t.

\,I

M+'

c.

180

Q> Ul

UV spectrum


..c

1.0

40 15

0.284 mg 110 mls path length: 0.5 cm


solvent: ethanol

20111.11,

Il

.b

40

80

C10H12OS

.1.

120

200

160

240

1.5

280

200

250

m/e

13C

300

A(nm)

350

NMR Spectrum

(20.0 MHz, CDCI 3 solution)

C-H C-H

I

-CH 3

I

H-C-H

C

C

I

I

160

200

I

I

C-H proton decoupled

H-C-H TMS

l

solvent II

120

40

80

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

10

288

9

8

7

6

5

4

3

2

1

o s (ppm)

Problem 200

1355

IR Spectrum (liquid film)

2000 1600 V (cm'")

3000

4000 100 80

800

1200

91

Mass Spectrum

199

UV Spectrum \J

..><
Q.

60

l/l

40

'0

Q)

C22H3009S2

155


M+ = 502 (<1%)

~

243

20 II

1,1

40

I

13C

80 I

I

~,

120

160 mle

I

I

287

II

I

200

240

280

r

-r

I

331

Amax 225 nm Amax 260 nm

(I091OE

4.6)

(I0910E

3.3)

Amax 272 nm

(I091OE

3.1 )

I

solvent: methanol

320

TnI

NMR Spectrum

T

I

(100.0 MHz, CDCI 3 solution) 0

70

DEPT

CH 2

1 CH

3t

CHt

68 ppm

I

liL~~" ,

solvent proton decoupled

I

I

70

LI

I

160

200

I

expansion

120

68 ppm

o

40

80

I 0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

-

10

9

8

7

6

5

TMS

-

-

4

I

3

2

1

o

o(ppm) 289

Problem 201

IR Spectrum (liquid film)

2000 1600 V (crn'")

3000

4000 100

1200

Mass Spectrum

63 43

~

80

Q) Q.

44

~

60

No significant UV

'"

..c

40

800

absorption above 220 nm

M+"

'0 ate

106/108

65

20 ~I

II

I.

40

80

120

200

160

240

280

m/e

13C NMR Spectrum (20.0 MHz. COCI 3 solution) I

H-C-H

I

I

C-H

H-C-H I

I

H-C-H I

TMS

proton decoupled

solvent

160

200

120

o

40

80

0 (ppm)

NMR Spectrum

1H

(100 MHz.

c, o,

solution) <

r'

20 Hz I----t

.:

expansion

~

r--

,

I

4.0

-

solvent residual

ppm

.:»

II

290

TMS

r----

.~

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o o(ppm)

Problem 202

( IR Spectrum (KBr disc)

3000

4000

100 80 60

1200

2000 1600 V (cm") M+'

800

Mass Spectrum

189

"'IJl'o,""

107

IJl

55

II)

'"

.c

40 '0

91

(fl. ..

20

80

40

120

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

I solvent

I

proton decoupled I

I

I

I

200

I

I

I

160

I

120

I

80

I

o

40

0 (ppm)

lH NMR Spectrum (200 MHz, CDCI 3 solution)

r---

I---

TMS

-

I

n I

I

I

10

9

8

I

I

I

I

I

I

I

7

6

5

4

3

2

1

I

0

o(ppm) 291

Problem 203

IR Spectrum 1136

(liquid film)

1200

2000 1600 V (cm'")

3000

4000

100

73

80

.><

60

III

800

Mass Spectrum

'I"II

0-

91

''""

.t:>

40 '0

;f?

20 II,

80

40

I

I

I

120

160 m/e

I

I

200

240

I

I

280

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

I

~

/proton decoupled

I I

I

I

I

I

160

200

solvent

• I

I

I

120

I

I

40

80

0

3 (ppm)

3.06

3.00 ppm

expansion

1H NMR Spectrum (400 MHz, CDCI 3 solution)

expansion 5.10

5.14

7.3

10

292

7.2

9

4.0

ppm

3.8

ppm

ppm

TMS

8

7

6

5

4

3

2

1

o

3 (ppm)

Problem 204

IR Spectrum

1695

(liquid film)

1670

2000

3000

4000

J 1600

1200

800

0.0

V (ern")

100

Mass Spectrum

131

0.5

80 ""

'"

'c-"

€

II)

60

II)

o c

o

II)

II)

..c

II)

'"

..c

1.0 '"

103

40 '5
77

20 1.1 "I .l

J

40

80

UV spectrum

M+" 174

C 12 H 14 0

I

120

160

200

240

1.5

280

200

250

m/e

13C NMR Spectrum (15.0 MHz, CDCI 3 solution)

350

300

A. (nm)

5x C-H 1 xC -CH 3 I

-CH I

proton decoupled TMS

lC

l

200

160

1

120

40

80

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

l 10

9

8

7

6

5

4

3

2

1

0

o(ppm) 293

Problem 205

1630

IR Spectrum

1680

(liquid film)

4000

1600 2000 V (em")

3000

100

1200

800

Mass Spectrum 77

80 "'
0.5

CD 0

131

c:

'"

€0

M+·

103

In

.c

132

'"

.c

'"

1.0

40 '0

o?-

20

0.0

,III

l

.1,'111

40

80

CgHaO 120

160

200

240

1.5

280

200

250

m/e

13C NMR Spectrum (50.0 MHz, CDC1 3 solution)

- - Resolves into two signals at higher field

expansion

i

i

150

130

160

200

,

,

150

130

120

ppm

- - Resolves into two signals at higher field

expansion

proton decoupled

350

300

A. (nm)

80

ppm

o

40

8 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

10

294

9

8

7

6

5

I

,

i

9.0

8.0

7.0

4

3

2

ppm

1

o

8 (ppm)

Problem 206

IR Spectrum

3340

(liquid film)

3000

4000

2000

1600

1200

800

V (crn'") 100 80

-'"

78

a.

UV Spectrum \I

M+·

91

III


60

Mass Spectrum

92

Amax

134


~ 250 nm (Io91Oc > 4.0)

105

l/l

III J:J

77

40 '0 ?ft:.

20

C gH1QO 40

I

80

I

I

120

160 role

I

I

200

240

I

13C NMR Spectrum

-

I

280

I

I

I

I

I

I

I

Resolves into two signals at higher field

(50.0 MHz. CDCI 3 solution)

I - - Resolves into two signals at higher field

solvent proton decoupled I

I

I

I

I

I

160

200

I

120

I

• I

I

80

I

o o(ppm)

40

,

exchanges with D 20

lH NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

10

9

8

7

6

5

4

3

2

I

i

3.8

3.0

1

o

o(ppm) 295

Problem 207

IR Spectrum (CHCI3 solution)

2000 1600 V (cm'")

3000

4000

1200

100

800

Mass Spectrum 57

80

0.0

0.5

III
III


.c

III

1.0

'0

0.210 mg 110 mls path length: 2.00 cm solvent: methanol

173

'*'

20

UV spectrum

III

III

.c

40

\I

€0

a.

60

B

C III

-'"

C13H 17CI 40

80

160

120

200

240

1.5

280

200

250

m/e

300

350

A(nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

r-

0---

5 x C-H

C-H

C

solvent rh

TMS

,. proton decoupled

160

200

120

o

40

.80

0 (ppm)

lH NMR Spectrum (100 MHz, CDCI 3 solution)

TMS expansion 100 Hz

296

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o o(ppm)

Problem 208

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (crn")

100 80

Mass Spectrum

103

""l'll

UV Spectrum

v

77

Amax

OJ

o,

60

::::I

250 nm (109101': > 4.0)

OJ

.c'" l'll

M+' 182/184

40 '0 -;fl..

20 ~ JI

•

40

80

120

160

200

240

280

mle I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution) C-H

--- 2xC-H expansion

C-H

I

I

I

200

ppm

I

i

I

I

130

solvent 1

I

I

135

C

proton decoupled

V

A

C-H

I

160

I

120

I

I

I

80

I

I

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion

r

8.0

10

9

8

7

6

5

4

6.0 ppm

7.0

3

2

1

o

o(ppm) 29'i

Problem 209 1377 1461

IR Spectrum (nujol mull) 2000

3000

4000

1600

1200

800

V (ern") 100 80 60

Mass Spectrum

102

UV Spectrum

..><

'C"D

M+"

cQ)

227/229

<Jl

'"

.0

40 15

197/199

oR-

20 C 80

40

I

13C

I

120

160 m/e

I

I

I

200

aH 6 N0 2Br

240

I

280

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDC'3 solution)

I

I DEPT

CH 2 • CH 3t CHt Resolves into two signals at higher field

solvent

1

!

I

'proton decoupled I

I

I

I

I

I

160

200 1H

I I

I

120

I

80

I

o

40

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansion

,.-

--'

~J

--- U

\..

'-----'

298

0 (ppm)

I

I

8.5

8.0

TMS

I

I

7.5

7,0

ppm

1

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm)

Problem 210

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (cm'")

100

91

Mass Spectrum

107

80 ""Cll Ql

Q.

60

Ql

en

Cll

.c

40

'0 ~

0"

20

,I .II 120

80

40

160

200

240

280

I

T

m/e

.

CH 2 , CH 3t CHt

I

I

2 separate peaks £~~m.

• at higher lfield strength

,

I

I

,

I I

I

I

I

I

I

160

200

II

,

I

I I

I

1

solvent

, 125 ppm

130 I

I

I

I

'

proton decoupled

I

resolves into 2 separate peaks at higher field strength

125 ppm

130

DEPT

I

I

I

I

13C NMR Spectrurm (100,0 MHz, COCI 3 solution)

I

I

I

40

80

120

1H NMR Spectrum

0

o(ppm)

Exchanges with 020

(400 MHz, COCI3 solution) expansion

expansion

~ I

3.7

10

3.6

9

ppm

8

1.9

7

1.8

6

ppm

5

1: 4

TMS

3

2

1

0

o(ppm) 299

Problem 211

IR Spectrum (KBr disc)

1700

4000

1678

2000

3000

1200

1600

800

V (cm'")

100

Mass Spectrum

90

80 ""til c60

UV Spectrum

Q)

118

Q) lJ)

til

.Q

40

'0

Amax

276 nm

(109108

3.1)

Amax

228 nm

(109108

3.9)

;ft.

solvent: methanol

20

162 I

J.JJl

'"-"-'-"'IL JI,' ..........-'------" Ib

-'--_

120

80

40

M+"(180<1%)

160

200

240

C

9H 80 4

280

mle I

I

I

I

I

I

13C NMR Spectrum

I

I

I

I

I

I

- - Resolves into two signals at higher field

(50.0 MHz, COCI 3/C03SOC03 solution)

solvent - - Resolves into two signals at higher field

I

~roton decoupled I

I

TMS

I

I

l solvent

I

I

120

160

200

I

I

I

I

I

o o(ppm)

40

80

I I

1H NMR Spectrum (200 MHz, COCI 3 solution)

TMS

exchanges with 0 20

10

300

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 212

IR Spectrum

1756

(liquid film)

4000

2000

3000

1600

1200

800

V (crn") 100 80

Mass Spectrum

165

UV Spectrum

~

Amax 232 nm Amax 300 nm

Ql C.

60

~

M+" 194

'"

.0

40 0 20

v (109 10 1:: 3.8) (109 10 1:: 3.6)

solvent: methanol

I,I,I~. "',.•J.i. 40

80

.1,,1.1 .Il

I.

120

C1OH1004 200

160

240

280

mle

10

9

8

7

6

5

4

3

2

1

o

3 (ppm) 301

Problem 213

IR Spectrum (CHCI 3 solution)

4000

1600 2000 V (crn'")

3000

100

1200

M+"

80

.><

60

Q)

l

Mass Spectrum

235

352-362

0.0

800

0.5

Q)

0-

CI>

'"

c

til

III,I , 320 340 360 (x20)

til

€0

III

UV spectrum

.0
III til

.0

1.0

165

40 '0 ;;t!.

0.934 mg 110 mls g path length: 0.1cm Q. path length: 2.0cm solvent: ethanol

C 14 H gCI 5

20

J

II, ,

J

40

80

120

l,

I,

.1

200

160

I.

240

1.5 280

200

250

m/e I

I

I

I

I

I

I

I

I

300

I

I

350

A(nm)

I

13C NMR Spectrum (20.0 MHz, CDCI3"solution) C-H C-H

001""

1

protoh decoupled

I

I

C I

I

200

TMS C-H

C

il

l

C

l

I

1

1

120

160

lil 1 I

I

I

1

80

40

I

0

o(ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

TMS

}

10

302

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 214

IR Spectrum (KBr disc)

4000

1745

2000

3000

1600

1200

800

0.0

V (em")

100

Mass Spectrum

196

80

C aH S03CI 3

.x: C1l Q)

o,

60

O.S

c:

-e g

M+" = 254 - 260

Q)

209

UV spectrum

.0 C1l

<J)

C1l .0

B C1l

1.0

40 15

1.592 mg 110 mls path length: 0.2 cm

~'"

solvent: ethanol

20

'--~""""""""""""~.L...o.....J...."",--,,,,,,,,,",,,,,--""""""~"""""....J....",,,--,,,,,,,,,,",,,,,--""""""~"""""....J....",,,--,--'--' 1.S w....................................-.........-...........L.o..J..............-...........

40

80

120

160 m/e

200

240

280

200

2S0

300

A (nm)

350

13C NMR Spectrum (50.0 MHz. DMSO-D6 solution)

Resolves into two signals at higher field -

solvent

proton decoupled

120

160

200

o

40

80

0 (ppm)

lH NMR Spectrum (100 MHz, DMSO-D6 solution)

exchanges with D20

1

1H

2H TMS

1H

11.8 ppm

solvent

10

9

8

7

6

5

4

3

2

1

o o(ppm) 303

Problem 215

1515

IR Spectrum (CHCI3 solution)

1750

2000

1600 V (ern")

3000

4000

1345

1200

800

0.0

Mass Spectrum

100 M+' 365/367/369 (1:2:1)

< 1%

C8HgN04Br2

80 ""

0.5

-e'"o

'" Q)

0-

60

s c:

en

Q)

en

286

'"

.0

40 '0

288

.0

1.0

'"

UV spectrum

;F.

0.494 mg /10 mls path length: 0.5 cm solvent: methanol

20 L...-~"""""""""""

1-,.....-'-""""""~-'--......L._.L............L..""""""~-'--......L._.L............L..""""""--0......1 1.5

40

13C

80

120

200

160 m/e

240

280

200

250

.-..... 300

A(nm)

............ 350

NMR Spectrum

(50.0 MHz, CDCI3 solution)

solvent

/

;'

proton decoupled

I

I

I

160

200

80

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

TMS

10

304

9

8

7

6

5

4

3

2

1

o

o (ppm)

Problem 216

r IR Spectrum (KBrdisc)

4000

2000

3000

1200

1600

800

V (ern")

100

Mass Spectrum

135

80

.><

60

CD 0. CD

co

II>

co .a

40 '0 cf!. '.

20 1

.IJ

40

II

M+'

120

80

=281 «

160

1%)

200

240

280

m/e 13C

NMR Spectrum

(50.0 MHz, CDCI 3 solution) expansion I

,

130

120

DEPT

CH 2

1 CH

3t

L

CHt

~ I

I

120

Resolves into two signals at higher field

--

Resolves into two signals at higher field

ppm

solvent

130

--

proton decoupled

200 1H

160

120

40

80

0

a (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansion

j I

ppm

6.8

10

9

8

7

expansion

A I

I

3.8

3.4

6

,

ppm

5

4

I

I

1.8

1.4

3

,J 2

1

TMS

o

a (ppm) 305

Problem 217

Note: ozonolysis of this compound affords acetone

IR Spectrum (liquid film)

1725

2000 1600 V (cm'")

3000

4000 100 80

1200

800

Mass Spectrum

99

0.0

0.5

~

o

c,

60 3l

\I

-e0

1Il

'"

155

.0 III

III .0

40

1Il C

III

UV spectrum

1.0

'0

0.307mg 110 mls path length: 0.5 cm solvent: ethanol

M+·

20

200 C1QH 16

40

80

120

200

160

240

04

1.5

280

200

250

m/e

300

350

A(nm)

13e NMR Spectrum (15.0 MHz, CDCI 3 solution)

off-resonance decoupled

TMS solvent

J

proton decoupled

1H

120

160

200

III

80

40

0

o(ppm)

NMR Spectrum

(100 MHz, CDCI 3 solution)

rr:

-

F

-.-J

1 306

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

l~

TMS

I

1

I

o

o(ppm)

Problem 218

IR Spectrum (liquid film)

1726

100

1200

800

Mass Spectrum

55

41

80

2000 1600 V (cm'")

3000

4000

96

.x: III

Q> C. Q>

60

1\10 significant UV

'"

III .0

40 15

M+' = 125 «

absorption above 220 nm

1%)

?ft..,

20

40

80

120

160

200

240

280

m/e

13C NMR Spectrum (100 MHz, CDCI 3 solution)

I

solvent

C-H

I 160

200 1H

120

H-C-H

H-C-H

I

I

C

I

I

C

TMS

I

I

40

80

0

cS (ppm)

NMR Spectrum

(100 MHz, CDCI 3 solution)

20 Hz

10

9

8

7

6

5

4

3

2

1

o

cS (ppm)

307

Problem 219

IR Spectrum (liquid film)

1725

2000

3000

4000

1600

1200

aoo

0.0

V (em")

100

69

ao "" ell

'"

41

0.

60

Mass Spectrum

UVspectrum

ell

<Jl

'"

..c

40 '0

0.401 mg /10 mls path length: 0.2 cm

M+'

0~

85 100

20

I

I

II.,

40

solvent: ethanol

C5H a02

I

120

ao

160 role

200

240

2aO

250

300

A. (nm)

350

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

~."""'-"'..........io.J'\o"......,..........';'''''~~II'-............w-,./-'I'-_.......J~-...--.....MJi.!'''''''.....,..,.....,w..-JJJ~ off-resonance decoupled

TMS solvent

, proton decoupled

!.

III

120

160

200

o

40

80

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI3 solution)

I

2.0

i

expansion

10

308

ppm

6.5

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 220

IR Spectrum (liquid film)

4000

2000

3000

1600

1200

800

0.0

V (ern")

100 80

oX

60

Q) Ul

0.5

s c

'"

-e'"

M+"

Q)

40

Mass Spectrum

95 Co

~ .a

110

1.0 '"

'"

.a (;

UV spectrum 0.231 mg 110 mls path length: 0.2 cm solvent: hexane

?ft. ..

20 II

tI

40

C aH 14

1I11 II

80

120

160

200

240

280

1.5w.......................................................................L............................u 200 350 250 300

A(nrn)

m/e

13C

NMR Spectrum

(20.0 MHz, CDC'3 solution)

off-resonance decoupled

proton decoupled

160

200

120

80

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

£ I

I

I

I

10

9

8

7

1 ,

I

I

I

6

5

4

3

J I

I

2

1

I

0

o (ppm) 309

Problem 221

IR Spectrum (liquid film)

2000 1600 V (ern")

3000

4000

100

1200

800

Mass Spectrum _ 75

80 "'" '"

'"

No significant UV

Q.

60

'" '" (J)

absorption above 220 nm

.0

40 '0

M+" =164

>'!. 0

« 1%)

20 .1

1111

40

80

120

200

160

240

280

m/e

13e NMR Spectrum (20.0 MHz, CDCI 3 solution)

off-resonance decoupled

120

160

200

80

o

40

0 (ppm)

lH NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

.~, I

10

310

I

9

I

I

I

8

7

6

5

4

3

2

A

1

o

o (ppm)

Problem 222

IR Spectrum (liquid film)

4000

2000

3000

1S00

1200

800

V (cm'")

100 80

Mass Spectrum

79

47

\I 103

~

Cll


SO

No significant UV

0.


l/l

.0

40

107

75

Cll

absorption above 220 nm

81

'0

M+' = 1521154 « 1%)

?ft.,.

20

109

I

III

80

40

C SH1302CI

II,

120

1S0

200

240

280

mle 13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

proton coupled

solvent proton decoupled

200

120

160

o

40

80

0 (ppm)

lH NMR Spectrum (200 MHz, CDC'3 solution) expansion

4.0

I

I

3.0

2.0

ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 311

Problem 223

IR Spectrum 1094

(liquid film)

4000

100

91

80

1200

2000 1600 V (cm'")

3000

181

800

Mass Spectrum

UV Spectrum

-" III

107


c-

60

log108 between 2 and 3


III .0

solvent: methanol

40 '0 ?f.

20 "

40

80

120

160

200

240

280

I

I

I

mle I

I

I

I

I

13C NMR Spectrum

I

I

I

I

......- resolves into 2 signals at higher field

(100 MHz, CDCI 3 solution)

DEPT

CH2 • CH 3t CHt

.....- resolves into 2 signals al higher field

rI

solvent

proton ,decoupled

I

I 120

160

200

"""J..

II 40

80

0

() (ppm)

lH NMR Spectrum (400 MHz, CDCI 3 solution)

expansion

expansion

4.0

3.6

3.8

ppm

Exchanges with 7.4

D20

7.3 ppm

TMS

~ 10

312

9

8

I

7

6

5

4

3

2

1

0

() (ppm)

Problem 224

IR Spectrum (liquid film)

100

1438

1200

2000 1600 V (ern")

3000

4000

80

1580

52

800

UV Spectrum

Mass Spectrum

\I

-"

Amax 257 nm Amax 270 nm

C1l

Ql

Co

60

Ul

40

'0

Ql

C1l

J::l


(10910£

3.4)

(10 9 ' 0 £ 2.6)

solvent: methanol

20 120

80

40

160

200

JLJ

240

280

m/e

I

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

____ ,PI

W.,.,

proton coupled

I

I

I

. w·r_·_~

I

I

_._., t

"' . . . .

I

I

I

I

:_I~~_._

proton decoupled II I

I

200 'H

160

120

80

o

40

0 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

expansion

I--

10

9

,

,

8.8

-

,

,

,

,

~

,

,

,

,

7.2

8.0

, ppm

TMS

-

8

I 7

6

5

4

3

2

o o(ppm) 313

Problem 225

IR Spectrum (liquid film)

4000

2000

3000

1600

1200

0.0

800

V (crn'")

100

.Mass Spectrum

M+'

0.5

93

CIl

o <:

80

..>::

60

'" CIl a.

€0

CIl

.0

III

Ul

Ul

.0

40

UV spectrum

III

III

'0
1.0

66

20

II ,II,

J

'~I

92

solvent: methanol

C SH 7N

'

40

0.636 mg I 10 mls path length: 0.5 cm

80

120

200

160

240

1.5

280

200

250

m/e I

13C

I

I

I

300

350

A(nm)

I

I

NMR Spectrum

(20.0 MHz, CDCI 3 solution)

l

III off-resonance decoupled

I

, proton decoupled

solvent

J

I

I

200

I

I

I

160

I

120

I

I

I

80

I

G

J

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDC'3 solution) 3H

TMS

314

2H

2H

A

~

j

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm)

Problem 226

IR Spectrum (liquid film)

2000

3000

4000

1600

1200

800

V (ern")

100

UV Spectrum

Mass Spectrum

80

-'"'

co

v

66


Amax 262 nm

Co

60

(10 9 10 E 3.6)


co

.0

solvent: methanol

40 '0 o~ ,

.'

78

J

20

J

j

40

120

80

200

160 m/e

280

C-H

C-H

13C NMR Spectrum

240

C-H

(50.0 MHz, CDCI 3 solution)

C-H C

solvent

160

200

120

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion

i~

'-J

I

I

I

I

8.6

8.4

I

I

7.4

7.0 ppm

~Jj ,

-

TMS

Ii

1

I

I

I

10

9

8

I

I

I

I

7

6

5

I

I

I

I

4

3

2

1

I

o

o(ppm) 315

Problem 227

IR Spectrum (liquid film)

2000

3000

4000

1200

1600

800

V (cm'")

100

Mass Spectrum

M+'

UV Spectrum

93

80 tii

Amax

Q)

o,

60

66

gs

263 nm (Io91O E 3.5)

'"

solvent: methanol

.0

40 '0 20 II"

II

dl

40

80

120

200

160

240

280

mle 13C NMR Spectrum

___W_ _L

(50.0 MHz, CDCI 3 solution)

I

solvent

I

proton decoupled

120

160

200

• 80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion with resolution enhancement (400 MHz) in acetone- d6 solution

10

316

9

8

I·

I

I

I

8.6 .

8.4

7.6

7.4

7

6

5

I

ppm

4

3

2

1

o

o(ppm)

Problem 228

IR Spectrum

1690

(liquid film)

4000

2000

3000

1600

1200

800

V (em")

100 80

78

Mass Spectrum

106

UV Spectrum

v

.><

'0-C"D

60

(IJ

40

'0

"'max 228 nm (I091OE 3.9)

CD

M+" =

43

'"

.t:J

121

"'max 267 nm (I0910E 3.5)

0~

solvent: ethanol

r

20

I I~ 40

120

80

160

200

240

280

m/e

13C NMR Spectrum (100.0 MHz, CDC'3 solution)

------'w"--------_ ~UJ'-----"----- __ solvent

120

160

200

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI3 solution)

9.11

-

~J I

.'

Jl

,

9.01 8.62

8.72

8.17

8.07

7.37

7.27

I J I

TMS

-

•

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o s (ppm) 317

Problem 229

IR Spectrum (liquid film)

1745

2000 1600 V (cm'")

3000

4000 100 80

1200

800

Mass Spectrum

106

0.0

0.5

.>t:

""

Ql

60

Q.

Ql

M+'

78

til

UV spectrum

165

"" 40 '0

.0

1.0

0.479 mg /1 0 mls path length: 0.2 cm

~

20

solvent: ethanol 11,11

C 9H 11N02

I

40

80

200

160

120

240

1.5

280

200

250

m/e

300

350

A (nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

C-H

C-H C-H

C-H

C-H

TMS

C /

C

protorydecoupled

200

III

120

160

l

solvent

!

,/

80

40

0

lH NMR Spectrum

TMS expansion

(100 MHz, CDCI 3 solution)

8.5

9.0

10

318

9

o(ppm)

8

7

7.5

8.0

6

5

4

ppm

3

2

1

o

o(ppm)

Problem 230 3400

IR Spectrum (CHCI 3 solution)

3000

4000

2000 1600 V (ern")

100 80

1200

800

Mass Spectrum 80

.><

81

'c.4l"

60

0.5

v

M+' 108

4l

UV spectrum

lJ)

'" '0

.J:J

40

0.0

1.0

';j!. ..

20 I III JII

~t

40

13C

0.159 mg 110 rnls path length: 1.00 cm solvent: ethanol

C 6H 8N 2

IJ

80

120

160 m/e

200

240

1.5

280

200

250

300

A(nm)

350

NMR Spectrum

(20.0 MHz. CDCI 3 solution)

off-resonance decoupled

TMS solvent

J

proton decoupled

III

200

160

120

o

40

80

0 (ppm)

1H NMR Spectrum (100 MHz. CDCI 3 solution)

TMS

exchanges with D?O

10

9

8

7

6

5

4

3

2

1

o

a (ppm) 319

Problem 231

IR Spectrum (liquid film)

1587

4000

2000

3000

1200

1600

800

V (cm") 100 80

.>e.

94

'"a.CD

60

UV Spectrum

Mass Spectrum

M+"

Amax 270 nm Amax 240 nm

CD til

'"

.c

40 '0

(10 9101':

2.5)

V

(1 0 9 10 1': 3.4)

53 67

cf?

~ J .J 7

20

9

II

1

40

solvent: methanol

C5 H6 N2

80

160

120

200

240

280

mle I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz,

coo 3 solution)

I DEPT

CHzt CH 3t cHt

solvent

I

, I

I

protondecoupted I

I

I

200 1H

I

I

I

I

120

160

I

~

I

I

I

40

80

I

o a (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution)

_J _t-=pans:Jl_ j

9.0

8.4 ppm

7.6

7.0

ppm

TMS

10

320

9

8

7

6

5

4

3

2

1

o

a (ppm)

Problem 232

IR Spectrum (liquid film)

4000

1200

2000 1600 V (cm'")

3000

100

800

Mass Spectrum

80

91

.>::

0.0

0.5

ctl

-eo

Q)

c.

60

fl c

ctl

III

Q)

.0 ctl

III

ctl .0

UV spectrum

1.0

40 '0 ;#. '.

39

65

2.396 mg / 10 mls path length: 2.00 cm

20

solvent: hexane

~.................. ...o....JL..._........L._............~....................o....J'__'_.....L._............

L....----'-...................

' _'_..L_..o.............o....J..............

120

80

40

160

200

240

280

1.5 1-1-0-............................. -........-..-'-...........-........................... 250 300 350 200

A. (nm)

m/e

13C

NMR Spectrum

(20.0 MHz, CDC'3 solution)

r -,

3 x C-H

expansion

1x 1x

C-H CH2

C I

ppm

130

TMS proton decoupled

160

200

120

1H NMR Spectrum

o

40

80

0 (ppm)

expansion

(100 MHz, CDCI 3 solution)

10

9

8

7

6

5

I

I

i

4.0

3.0

2.5

4

3

2

ppm

1

o o (ppm) 321

Problem 233

expansion

expansion

JL i

_JL

~

i

.~

i

6.70 ppm

6.75

TMS

~

i

2.25

2.20 ppm

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

322

I

0

o(ppm)

Problem 234

IR Spectrum 1692

(KBr disc)

4000

2000

3000

1600

1200

800

0.0

V (crn'")

100

Mass Spectrum

95

80

-'" <'ll

60

II)

0.5

Ql

o

c:

<'ll

€

Ql

0-

0

M+"

Ql

II)

.Q

<'ll

112

<'ll

.Q

UV spectrum

1.0

40 '0

0.462 mg /10 mls path length: 0.2 cm

o~ ,

20

II

uJ ,I,

,I.

40

CS H 40 3

I

160

120

80

200

240

solvent: ethanol

1.5

280

200

250

m/e

300

350

A(nm)

13e NMR Spectrum (20.0 MHz, COCI 3 solution)

J-

off-resonance decoupled

TMS

solvent proton decoupled

160

200 1H

120

NMR Spectrum I

~

.,oh'09·' ___ with 0

I

100 Hz

j[-

j 20

TMS

expansion

(100 MHz. COCI 3 solution)

J

0 /0 (ppm)

40

80

JL

CHCI 3

,-J ~

11.3 ppm

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o o(ppm) 323

Problem 235

IR Spectrum (liquid film)

1677

2000

3000

4000

1600

1200

800

0.0

V (crn") 100

57

80

Mass Spectrum

0.5

95

.:.f.

'c."

'0" "' '"

of

G)

60

G)

u c:

G)

"' '"

.J:J

M+"

.J:J

1.0

152

40 '0 *20

.,,1

40

I

I

120

80

L

II

UV spectrum 0.214mg/10mls path length: 0.5 cm

C 9H 1202 200

160 m/e

240

solvent: cyclohexane

1.5

280

200

250

300

A (nm)

350

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

off-resonance decoupled

solvent

proton decoupled

TMS

I

200 1H

120

160 I

NMR Spectrum

o

40

80

0 (ppm)

I

50 Hz

(100 MHz, CDCI 3 solution)

CHCI3 expansion

• \.

324

I

I

I

10

9

8

,- -

.Iv..

~

v-r-r-r-:

TMS ----1

I

I

I

I

I

I

I

7

6

5

4

3

2

1

o s (ppm)

Problem 236

IR Spectrum (CHCI3 solution)

4000

1510

2000

3000

1600

1320

1200

800

V (crn'")

100

Mass Spectrum

80

.><

60

Q) Ul

0.5

'" Q)

0-

40

M+"

82

'" '5

..c

174

1.0

UV spectrum

c/!. . .

0.210 mg 110 mls path length: 0.5 cm

20

,I

11.11

40

80

C4H2N20 4S

I

120

160

200

240

solvent: ethanol

1.5

280

200

250

m/e

300

350

A(nm)

13C NMR Spectrum (20.0 MHz, CDCI 3 solution)

off-resonance decoupled

TMS solvent proton decoupled

160

200

120

o

40

80

1H NMR Spectrum

0 (ppm) TMS

(100 MHz, CDCI 3 solution)

expansion

25 Hz

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

o o(ppm) 325

Problem 237

1675

1515

IR Spectrum 1360

(CHCI3 solution)

2000 1600 V (ern")

3000

4000

100 80

1200

800

Mass Spectrum

156

0.0

0.5



€o

Q)

o,

60

.,

(;

c

~

til

Q)

UV spectrum

.J:>

til


.J:>

M+"

.110

40 '0


1.0

199

~

2.306 mg I 20 mls path length: 0.1 cm solvent; dioxan

20

40

80

120

160

200

250

mle

350

300

A(nm)

13e NMR Spectrum (20.0 MHz, CDCI 3 solution)

solvent

TMS

off-resonance decoupled

proton

~d;c6uPled

.l .",

.L

200

160

1H NMR Spectrum (100 MHz, CDCI 3 solution)

326

"

120

80

40

o

0 (ppm) TMS

6H

Problem 238

IR Spectrum (KBr disc)

2000 1600 V (cm'")

3000

4000

1200

800

I

12 ppm ,--

r-- -

----

-

TMS I

I

I

I

I

I

I

I

I

I

109

8

7

6

5

4

3

2

1

I

I

0

o (ppm) 327

Problem 239

IR Spectrum (KBr disc)

2000

3000

4000

800

1S00

V (cm'") 100 80

Mass Spectrum

UV Spectrum

»:

Amax 22S nm Amax 256 nm

'"


0.

SO



'"

.0

40 '0


20 I,"

II

Iii

120

80

40

,

1S0

200

240

280

I

I

I

I

I

I

I

(l091Of:

3.7)

Amax

288

nm (1091Of: 3.3)

Amax

297

nm (10910 f: 3.5 ) solvent: ethanol

m/e I

(l091Of: 4.4)

I

I

J

I

,

I

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

expansion

j DEPT

,

CH,. CH 3t CHt

I

126

X"

,

proton decpGpled /

,

140.5

I

I

,

140.0

ppm

,

,

,

126

122 ppm

I

I - - solvent I

I

I

I

, 122 ppm

-ClU--L

,

,

I

120

160

200 1H

1, 1

,

,

I

80

o

40

3 (ppm)

NMR Spectrum

(400 MHz, CDC'3 solution) expansion

7.8

8.0

7.4

7.6

ppm

TMS

10

328

9

8

7

6

5

4

3

2

1

o

cS (ppm)

Problem 240

IR Spectrum

3402

(KBr disc)

2000 1600 V (cm'")

3000

4000

100 80

1200

800

Mass Spectrum

143

UV Spectrum

~

Amax 229 nm Amax 284 nm

Q)

0-

60

ill

'"

.c

40 '0 cf?..

(lo910f: 4.4) (lo910f: 3.8)

solvent: ethanol

20 I

120

80

40

160

200

240

280

I

I

I

mle I

I

I

I

I

140

130

120

24

ppm

expansion

, 140

,

I

,

130

120

I

I

I

I

,

24

solvent •

I

I

t CH

3+

CH+

i

22 ppm

I I

I

120

160

200

CH2

22 ppm

,

i

ppm

II I

DEPT

j

I

proton decoupled I

T

"P'MIoO~

COCI3 solution)

II

-1

r

I

~ , , ,

~ , , , ,

13C NMR Spectrum (100.0 MHz,

80

I

I

I

o

40

0 (ppm)

1H NMR Spectrum (400 MHz, COCI3 solution)

expansion

. 7.5

7.8

10

9

8

7

6

7.2

5

Exchanges with 020

I

ppm

4

TMS

3

2

1

o

o(ppm) 329

Problem 241

IR Spectrum (liquid film)

1796

4000

2000 1600. V (em")

3000

100

1200

800

Mass Spectrum

155

UV Spectrum

43

80

..><

60

Q)

III

Q)

a.

'"

M+"

'0

98

*-

I'

III .0

40 20

,11 III

I

I

,I

40

solvent: ethanol

80

I

120

160 m/e

I

I

I

200

240

I

280

I

I

I

I

I

I

13C NMR Spectrum (50.0 MHz, CDC1 3 solution)

I DEPT CH2

t

CH3

t

CH

t

1H NMR Spectrum (200 MHz. CDCI 3 solution)

expansions

-L ,

,

,

,

,

5.0 ppm

5.3

"

.:» , , , , ,

,

3.0 ppm

3.3

V--

, '------, ,

,

V-

1.8 ppm

2.2 r-

330

-

~

~

TMS

I

I

I

I

I

I

I

1

I

I

10

9

8

7

6

5

4

3

2

1

I

o

o(ppm)

Problem 242

IR Spectrum

1760

(liquid film)

4000

2000

.3000

1600

1200

800

V (em")

100

Mass Spectrum

43

80

-'"

60


III

e

C. 'll

No significant UV 72

III J:l

M+"=

40 '15

absorption above 220 nm

100

~

20 i

I

d

40

80

CSHa0 2 160

120

200

240

280

m/e

13C NMR Spectrum (100.0 MHz, CDCI 3 solution)

proton decoupled

120

160

200

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution)

~---.--....

4.35 4.30

expansions

-.,-----,---..-

-.,-----,---....

4.10

3.80 3.75

4.05

-....----.- ---,---..---

~.

2.6

2.5

TMS

10

9

8

7

6

5

4

3

2

1

o

o(ppm) 331

Problem 243

IR Spectrum (liquid film)

4000

2000 1600 V (cm")

3000

1200

100

800

Mass Spectrum 42

80

-'"

60

l /l

''a""-

No significant UV

'" '"

..c

40 '0

absorption above 220 nm

56

oft

20 I..i ,II

40

I

I

I

13C

80

120

160 m/e

I

I

200

240

I

I

280

I

I

,j

NMR Spectrum

(20.0 MHz, CDC'3 solution)

L

L

(

I

I

I

1H

TMS

solvent

I I

I

I

I

120

160

200

I

JL

off-resonance decoupled

proton.decoupfed

I

I

I

I

I

80

I

40

I

0

o (ppm)

NMR Spectrum

(100 MHz and 400 MHz, CDCI 3 solution) 400 MHz

I

I

I

4.36

2.48

2.28

TMS

1

expansions at 400 MHz

10

332

9

8

7

6

5

4

3

2

1

0

o (ppm)

Problem 244

IR Spectrum

1722

(KBr disc)

Note: this compound has no

1751

significant dipole moment 4000

2000

3000

1600

1200

800

V (ern") 100 42

80

Mass Spectrum

70

V

.-

"''"" 0Q)

60

No significant UV

Q)

en

M+'

'"

.c

absorption above 220 nm

140

40 '0 o~ "

20

, ,I

CaH 120 2

.d.

40

120

80

160

200

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum

L

(20.0 MHz, CDCI 3 solution)

l1J

_I

off-resonance decoupled

TMS

proton decoupled

solvent

l I

I

I

I

200

I

I

I

I

160

120

I

I

I I

I

80

I

I

o s (ppm)

40

lH NMR Spectrum (100 MHz, CDCJ3 solution)

TMS

I I

10

I

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

1

I

0

() (ppm)

333

Problem 245

,

IR Spectrum (nujol mull)

4000

2000

3000

1600

1200

800

V (crn")

100

Mass Spectrum ~

80

+"

158

(\)

0-

·186

~

60

'"

.0

40 '0

*

20

C 14 H18 40

120

80

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100 MHz, CDCI 3 solution)

1 off-resonance decoupled

r

/ proton Iclecoupled I

,

solvent

I

I

I

I

I

I

120

160

200

I

I

40

80

I

o

0 (ppm) TMS

1H NMR Spectrum (100 MHz, CDCI 3 solution)

10

334

9

8

7

6

5

4

3

2

1

o o(ppm)

Problem 246

IR Spectrum

1680

(KBr disc)

4000

2000

3000

800

1600

V (cm") 100

Mass Spectrum

180

80

UV Spectrum

M+"= 208

.:.< III

Q)

a.

60

152

Q)

VI

III .0

40

'0 ?fi.-'

20

1

l J

,I

A. max 255 A. max 275

nm (109108 4.7)

A. max 330

nm (1091083.8)

nm (1091084.3)

J

solvent: ethanol

120

80

40

V

200

160

240

280

mle I

I

I

I

I

U

(100.0 MHz, CDCl a solution)

DEPT

CH 2

1CHat

,

, 135

CHt

130

r

I

expansion

13C NMR Spectrum

I

I

I

I

I

I

i

ppm

expansion

proton decoupled

I

I

I

U

, 135 I

I

I

130 I

I

120

160

200

i

solvent

~

,

ppm I

I

o

40

80

0 (ppm)

1H NMR Spectrum (400 MHz, CDCI 3 solution) expansions

l-

I--

solvent residual

1

8.4

J

~

J

8.3

8.2 ppm

7.9

Itt

7.8

7.7

ppm

TMS

-

-

I

I

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 335

Problem 247

IR Spectrum (nujol mull)

2000 1600 V (em")

3000

4000

1200

0.0

800

,i;}

100

Mass Spectrum

80

0.5

"'c." Q)

60

-e0

v·

Vl

Q) Vl

l'll

1.0

240

40 '0

* d

I

I..

,J

120

80

40

13C

.c

M+"

l'll

.c

20

Q)

o

c:

l'll

l'll

I

I

,1,1

IlL

.Ii

l

200

160 m/e I

I

.~

8.148 mg /10 mls path length: 1.00 cm

C 18H 24 240

I

I

solvent: hexane

1.5

280

250

200

I

I

UV spectrum

I

300

350

A (nm)

I

I

NMR Spectrum

(100 MHz, CDCI 3 solution)

1 off-resonance decoupled

I

,

TMS

solvent

I

proton decoupled I

I I

I

I

I

I

I

120

160

200

I

I

I I

I

80

I

I

a

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCI 3 solution)

TMS

336

I

I

I

I

I

I

I

10

9

8

7

6

5

4

~(J , 3

I

I

2

1

I

a

o(ppm)

Problem 248

IR Spectrum (nujol mull) 4000

2000

3000

1600

1200

800

V (crn'") 100 80

Mass Spectrum .>t:.

M+'

'"

Q)

o,

60

Q) Ul

40

'0

UV Spectrum

Amax 249 nm Amax 257 nm

228

'"

.0

Amax 273 nm

(/:. ..

(10 9 10 8 5.0) (10 9 10 8 5.2) (109108

4.4)

20 solvent: ethanol

40

120

80

200

160

240

280

m/e I

I

I

I

I

13C NMR Spectrum

I

I

I

I

I

I

I

I

I

I

I

C-H

(50.0 MHz, CDC'3 solution)

C-H

solvent

I

I

I

I

I

I

120

160

200

1H

I

I

•

80

o

40

0 (ppm)

NMR Spectrum

(200 MHz, CDCI 3 solution) expansion

c

J I

l

) I

l I

I

8.5

7.5

I

ppm

TMs

0'

1

10

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 249

IR Spectrum (liquid film)

4000

2000

3000

1200

1600

800

V (crn'") Mass Spectrum

100 80

43

"''"" Q)

C-

60

(J)

40

'0

No significant UV

Q)

'"

absorption above 220 nm

~

~

20

40

120

80

200

160

240

280

m/e I

I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (20,0 MHz, CDCI 3 solution)

III I~

~

off-resonance decoupled

,"

r

TMS solvent

proton decoupled I

I

I

I

160

200

I

120

I

j I

l I

80

I

I

o () (ppm)

40

lH NMR Spectrum (100 MHz, CDCI 3 solution)

-

-

TMS

Jf

10

338

9

8

7

6

5

4

3

2

1

0

() (ppm)

Problem 250

IR Spectrum (CHCI 3 solution)

4000

2000 1600 V (ern")

3000

1200

100

800

Mass Spectrum 55

V

~

80

No significant UV

Q)

c-

~

60

absorption above 220 nm

to

..0

82

40 '0 20

40

13C NMR

120

80

spectru~On)

200

160 m/e

240

280

I

(20.0MH'_ COCI, ~I""~

4

I

X H-C-H I

off-resonance decoupled

TMS solvent

proton decoupled

il! 160

200

120

80

o

40

0 (ppm)

lH NMR Spectrum (100 MHz, COCI 3 solution)

4H 4H

exchanges with 0 20

lH

~

TMS

I

I

I

I

10

9

8

7

·1

6

,

I

I

I

I

5

4

3

2

1

I

o o(ppm) 339

Problem 251 IR Spectrum (KBr disc)

1200

2000 1600 V (ern")

3000

4000

100

800

Mass Spectrum

UV Spectrum

80 ;'g

Amax 310 nm

Q)

c..

60

~

'"

(10910£

solvent:

..c

1.2)

isooctane

40 '0

20

120

80

40

160

200

240

280

I

I

I

mle I

I

I

I

I

I

I

I

I

13C NMR Spectrum (100,0 MHz, COCI 3 solution)

- - Resolves into two signals at higher field

,

solvent

I I

200

-

I

120

160

1H NMR Spectrum

I

I

I

I

I

o

40

80

0 (ppm)

expansion

expansion

(400 MHz, COC'3 solution)

I

Exchanges with 020

, 2.4

10

340

9

8

7

2.2

6

ppm

1.4 ppm

1.6

5

4

3

TMS

2

1

o

o(ppm)

Problem 252 3212

IR Spectrum 1658

(KBr disc)

1600

2000

3000

4000

1200

800

V (crn")

100

Mass Spectrum

55

80 "'C1l" Ql a. 60 Ql

V

C1l

40

No significant UV

56

Vl

.c

M+" 84

'0 ~ '.

85

absorption above 220 nm

113

20

C 6H 11 NO

k.

1.1

120

80

40

160

200

240

280

mle 13C NNiR Spectrum (50.0 MHz, CDCI 3 solution)

[fll ---"--~-----JII-

lW_.

solvent

proton decoupled

160

200

120

__

80

o

40

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

l

expansion

---

I

3.0

10

9

8

2.0

7

ppm

6

5

4

3

2

1

o

o (ppm)

Problem 253

4000

2000 1600 V (ern")

3000

1200

100

800

Mass Spectrum 58

80

.x:
C-

60

No significant UV

Q)

III


absorption above 220 nm

on

40 '0
20

88

III ,Il

M+' 119

I 80

40

200

160

120

240

280

mle I

13C

I

I

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50,0 MHz, COCI 3 solution)

DEPT

I

CH 2 , CH 3t CHt

I solvent

proton decoupled

W I

I

I

I

I

I

120

160

200 1H

I

I

I

40

80

NMR Spectrum

o(ppm)

6H

expansions

(400 MHz, COCI 3 solution)

0

30 Hz r---l

1H

1H

1H

1H

A~ I

I

I

3,79

3.66

3.49

1H

I

2.50

I

ppm

2H exchanges with 0 20 __

342

~

-»JL

2.22

TMS

An

I

I

I

I

I

I

I

10

9

8

7

6

5

4

ppm

*~ - I

3

I

I

I

2

1

I

0

o(ppm)

Problem 254

IR Spectrum (KBr disc)

4000

2000

3000

1200

1600

800

V (cm")

100

Mass Spectrum

58

80

UV Spectrum

v

sc III

Amax 258 nm

Ql

0-

60

(lo91QE 2.3)

Ql CIl

III .0

40

'0

20

*'

M+' '.

solvent: methanol

=165 «

1%)

105 l

I.

80

40

J

120

160

200

240

280

m/e

13C NMR Spectrum (50.0 MHz, COCI 3 solution)

I

proton decoupJed .

160

200

120

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, COCI 3 solution)

expansion

i

i

I

4.4

4.0

2.8

I

2.4 ppm

I

1.2

0.8

2H near l) 2.6 exchange with 0 20

TMS

I

7.2

7.6

10

9

8

7

6

5

4

3

2

1

o

o (ppm) 343

Problem 255

IR Spectrum

1666

(liquid film)

100 80 60

2000 1600 V (crn'")

3000

4000

1200

800

Mass Spectrum

56 .><

'
No significant UV


Ul

'"

.0

40 '0

absorption above 220 nm

86 .

?t-

20

M+'

,~

101

I

II

40

80

I

I

CSH 11NO

1

120

160 m/e

I

I

I

200

240

I

280

I

I

I

I

I

I

13C NMR Spectrum

_.~------'~

(50.0 MHz, CDCI 3 solution)

,.-

--

--Ju

pj-oton decoupled I

I

I

I

I

I

120

160

I

80

I

I

o

40

<5 (ppm)

-

I

j

(200 MHz, CDCI 3 solution)

1H I

l~L_

I

I

1H

NMR Spectrum

expansion

_

•

I

I

200 1H

solvent __A..__ _.....ll.-_-J.L

I

I

8.4

8.0

I

r -,

exchange with D 2 0 on warming

expansion

t

9H

t ~

I

I

I

8.0

7.0

6.0

I

ppm

ppm

TMS II

I

•

I

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

o

<5 (ppm)

344

Problem 256

3376

IR Spectrum

1718

(KBr disc)

1590

2548

4000

2000

3000

1200

1600

800

V (crn'")

100

Mass Spectrum

43

v

~

80

No significant UV

Q)

a.

60

~

absorption above 220 nm

1-2

40 '0 of?

20

I,

1.1

j

40

I

M+"= 163

80

120

160 m/e

200

240

280

I

I

I

I

I

I

I

CS H gN0 3S

.1,

I

I

I

13C NMR Spectrum

I

(100.0 MHz, CDCI 3/DMSO-d6 solution)

DEPT

CH2

f

CHJt CHt

~

proton decoupled

,

I

I

200

solvent

f

I

I

I

I

120

160

I

I

I

lTI I

,

,

o

40

80

0 (ppm)

expansions 1H NMR Spectrum (400 MHz, CDCI3/DMSO-d6 solution)

expansion

~s ,

i

i

i

10.0

11.0

withD20

9.0

ppm

7.7

7.6

i

i

4.8

4.7

i

3.0

2.9

ppm 1.8

r 10

note broad signal

9

1.7 ppm

TMS

8

7

6

5

4

3

2

1

o

o(ppm) 345

Problem 257

Note: irradiation of the signal at Ii 6.58 in the 1H NMR produces an enhancement of the

IR Spectrum (KBrdisc)

signals at Ii 6.66 and 4.45 ppm via the NOE

4000

2000

3000

1600

1200

800

V (crn") 44

100 80

Mass Spectrum

UV Spectrum

~ Ql

C.

60 3l
.n

40 '0

Amax 220 nm

(Io910E

3.8)

Amax 280 nm

(Io910E

3.4)

solvent: H 2 0 pH 7

20 40

120

80

200

160

240

280

m/e

13e NMR Spectrum (100.0 MHz, 0 20 solution)

resolves into 2 peaks at higher magnetic fields proton

..

9~coupled

200

120

160

1H NMR Spectrum

80 1H

(400 MHz, OMSO-d6 solution)

L-

1H

0 (ppm)

2H

3H

Note: there are 4 exchangeable protons which appear with the residual H 2 0

1H

o

40

solvent residual

residual H 2 0 in solvent

1H

2.5

2.6 4.5

ppm

4.4 ppm TMS

6.8

10

346

6.7

9

6.6

ppm

8

7

6

5

4

3

2

1

o

o (ppm)

Problem 258

IR Spectrum (KBrdisc) 3405

1667

2000

3000

4000

800

1200

1600

V (crn'") 100

Mass Spectrum

130

UV Spectrum \I

80

.>t!.

'"

Amax 220 nm

(10910£

4.6)

<J)

Amax 273 nm

(10910£

3.8)

(10910£

3.8)

(10910£

3.7)

OJ o, OJ

60

'"

.0

40 '0

~

Amax 280 nm Amax 289 nm

0"

20

80

40

I

13C

I

I

120

160 m/e

200

240

I

I

I

I

280

solvent: methanol

I

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, D20 solution)

DEPT

CH 2 , CH 3t CHt

proton decoupled

J

I

I

I

I

I I

I

120

160

200 lH NMR Spectrum

I

I

I

expansion

H20 and HOD in solvent

,

, 4.4

7.5

10

0 (ppm)

1L

.t:

wilhthe residual H 20

expansion

I

o

40

80

Note: there are 4 exchangeable protons which appear

(400 MHz, D20 solution)

I

7.0

9

4.2

3.4

ppm

3.2

ppm

ppm

8

7

6

5

4

3

2

1

o s (ppm) 347

Problem 259

3276

IR Spectrum

1702

(KBr disc)

100

800

Mass Spectrum

131

43

80

1200

2000 1600 V (cm'")

3000

4000

1666

'"'" c. Ql

60

Ql Vl

'"

D

,

40 '0 ;ft.

20

!.

,II 40

I

13C

I

I

80

120

160 m/e

200

240

280

I

I

I

J

I

I

I

I

I

I

NMR Spectrum

(100.0 MHz, COCI 3 solution)

DEPT

Il

CH 2 , CH 3t CHt

,

solvent proton decoupled /

I

I

I I

I

I

NMR Spectrum

(400 MHz, COCI 3 solution)

expansion

6.8

10

348

6.7

9

I

120

I

I

I

I

() (ppm)

0

40

80

expansions

~ ,

Jl

I

I

I

160

200 1H

I I

4.6

4.5 ppm

Exchanges with 020

Jul JL ,

,

3.4

3.2

ppm

,

,

2.8

2.7

'" expansion

f

8

---. 7

~l"

ppm

,

,

2.0

S

ppm

f

1.9 ppm

TMS

6

5

4

~

r

3

2

1

o

() (ppm)

I

Problem 260

IR Spectrum (KBr disc)

4000

1600 2000 V (cm")

3000

100

1200

800

Mass Spectrum

84

\,I

80 "'
No significant UV

Ql Vl


40

absorption above 220 nm

'0 ~ 0,.

20

102

JJ

J

M+"= 147 «

1%)

CSH gN0 4

I

160

120

80

40

200

240

280

m/e I

I

I

13C NMR Spectrum (100,0 MHz, 020 solution) ,"

DEPT

I

I

I

I

I

I

I

I

I

I

I

I

I

.

CHz' CHat CHt

I

l

I

proton decoupled I

I

120

160

200 1H NMR Spectrum (400 MHz, 020 solution)

80

I

I

I

40

0

o(ppm)

H20 and HOD in solvent

Note: there are 4 protons which exchange with the 020 solvent

I

Lexpansions

~ i

i

4,2

4.0

r-r--

~ JL i

i

2,9

2,7

2.4

,.-

2,2 ppm

-

---'

-'

'--'

10

9

8

7

6

5

4

3

2

1

0

o(ppm) 349

Problem 261

IR Spectrum

1715

(liquid film)

4000

2000

3000

1600

1200

0.0

800

V (cm'")

100

Mass Spectrum

44

0.5

sc-

ttl

€

~

60

CD

o

c:

80 "'"

o

III

58

.0 ttl

2 40 '0

1.0

UV spectrum

*"

20

49.5 mg 110 mls path length: 1.00 cm solvent: hexane

40

80

120

160

200

240

280

250

I

I

I

I

I

I

I

I

300

. A(nm)

m/e I

I

I

350

I

13C NMR Spectrum (20.0 MHz, CDCl a solution) I

H-C-H I C-H

proton decoupled

C-H

TMS

/

solvent

I

III ,

I

I

I

I

I

I

120

160

200

I

I

I

80

I

I

o

40

0 (ppm)

1H NMR Spectrum (100 MHz, CDCl a solution) expansion of 400 MHz spectrum 20 Hz

I

9.75

J

10

350

9

J

I

8

TMS

2.21

2.31

7

6

5

4

3

2

1

o

o(ppm)

Problem 262

IR ~pectrum (liquid film)

1200;-""---......J---800 '

3000

4000 100

57

Mass Spectrum

80 "" 'a.<"1l 60 <1lVI

No significant . UV

'"

absorption above 220 nm

.0

40

'0 ?fi. "

20

M+"--

40

120

80

130 « 1%)

160

280

200

m/e

13e NMR

(1000 M Spectrum . Hz, CDCI 3 solution)

proton decoupled

o o(ppm) 1H NMR S (400 M

pectrum

J- II 5.8

5 ' . 7ppm

, 5.3

5:2

8

48 4.7 ppm

p~m

':5 ':4

,:,

ppm

6

5

,:

,

,pm

f

JJJ 7

,:,

4

TMS

3

2

0

o(ppm) 351

Problem 263a IR Spectrum (liquid film) A 400 MHz 1H NMR spectrum (with expansions) is given on the following page

100 80

2000 1600 V (cm'")

3000

4000

28

1200

Mass Spectrum

56

30

800

sc

'C"D

0-

60

CD

rn

No significant UV

M+"

'"

.0

absorption above 220 nm

57

40 '0

*20

C 3H 7N

jJ 120

80

40

160

240

200

280

mle I

I

I

I

I

I

I

I

I

I

I

13C NMR Spectrum (20.0 MHz, COCI 3 solution) I

I

H-C-H

H-C-H

I

I

C-H

TMS solvent

, prdton decoupled I

I

l

III I

I

I

160

200

I

I

120

I

I

I

80

40

1H NMR Spectrum (100 MHz. COCI 3 solution)

l

expansion

AM

~ ,

6.0

I

,

i

5.0

4.0

I

0

exchanges with 0 20

ppm

Jf 10

352

9

8

7

6

5

o (ppm)

TMS

4

3

2

1

o

o (ppm)

Problem 263b

1H

NMR Spectrum

2H

(400 MHz, COCI 3 solution)

2H exchanges with 0 20

2H 1H

7

5

6

4

3

2

1

o

o (ppm)

Expansion of regions of the 400 MHz NMR spectrum

5.996 ppm

20.0 Hz

5.152 ppm

5.040 ppm

3.307 ppm

353

\

'f

Problem 264

.s:

l

1

IR Spectrum (CHCI3 solution)

I

4000

I

I

3000

2000

I

1600 V (ern")

I

I

1200

800 ~

100 80

~,

Mass Spectrum M+'

-'"

= 136

'" Ol

c-

60

Ul

40

.a '" '0

No significant UV

Ol

absorption above 220 nm

;i<.

JI~ 1

20

C1QH 16

I

II

1H NMR Spectrum (400 MHz, CDCI 3 solution)

{ expansion

/

/

i

'-----,

1.'9

i

,

1.7

ppm TMS

! I

10

354

I

I

I

I

9

8

7

6

I

5

4

3

I I

2

1

o a (ppm)

Problem 265

IR Spectrum (CCI 4 solution)

4000

100 80

2000 1600 V (crn'")

3000

1200

800

Mass Spectrum

59

"''""

Q)

0.

60

No significant UV

Q) (Jl

'"

absorption above 220 nm

.D

40 "6

M+" = 118 «1%)

~

103

20 III

I

C6H 140 2

I

80

40

I

I

I

120

160 m/e

I

I

I

240

200

I

280

I

I

I

I

13C NMR Spectrum (100.0 MHz, COCI 3 solution)

I [

solvent

proton decoupled I

I

L-I I

I

I

I

120

160

200

I

I

W I

I

I

80

40

I

0

o(ppm)

expansion with irradiation at 64.0 PPM

1H NMR Spectrum (400 MHz, COCI3 solution) expansion

expansion

4.05

3.95

ppm

,

i

1.5

1.3

ppm

expansion

Exchanges with 020

, 4.4

10

9

L

4.0 ppm

8

7

6

5

1.4

4

3

1.0 ppm

2

1

o o(ppm) 355

Problem 266

Note: irradiation of the signal at /) 6.45 in the

IR Spectrum

1H NMR produces an enhancement of the

(liquid film)

signals at Ii 3.4 and 3.7 ppm via the NOE

4000

2000 1600 V (cm'")

3000

100

1200

800

Mass Spectrum

M+"

UV Spectrum

164

80 """ 'QC-"l 60 Ql <J)

55

'"

149

77

J:l

A. max 281 nm A. max 230 nm

103

40 '0 ~

(109108 3.5) (109108 3.6)

solvent: methanol

20

120

80

40

200

160

240

280

mle I

I

I

I

I

I

I

I

I

I

f

I

13C NMR Spectrum (50.0 MHz, COCI 3 solution)

I DEPT

CH2

1 CH

3t

CHt

,I I

I

II

proton decoupled I

I

I

200 1H NMR Spectrum

I

I

1

solvent

II I

120

160

I

80

I

I

40

I

o

expansion

(200 MHz, COCI3 I C 606 solution) exchanges

expansion with resolution enhancement

I

7.0

10

356

9

~ I

I

6.0

5.0

expansion

ppm

0 (ppm)

Problem 267

IR Spectrum (CCI4 solution)

4000

2000

3000

1600

1200

800

V (ern")

100 80

203/205

UV Spectrum

Mass Spectrum

V

~

109108 >

<1l Q)

c.

60

4.5

M+" 218/220

Q) U)

<1l .0

a

40

183

"#. ..

20 I

I

40

I

80

.1

L

.Il ,Ih,

1.1

160

120

C14H15 CI

I

200

240

280

mle 13C NMR Spectrum (75 MHz, CDCI 3 solution)

solvent

proton decoupled

160

200 lH

120

o

40

80

8 (ppm)

NMR Spectrum

(300MHz, CDCI 3 solution) expansion

I

I

iii

i

7.0

i

i

ppm

6.5

TMS

10

9

8

7

6

5

4

3

2

1

o

8 (ppm) 357

Problem 268

4000

2000 1600 V (cm'")

3000

1200

100

800

Mass Spectrum 43

80

.>< CD


0-

60

No significant UV


lI)

CD

.c

absorption above 220 nm

40 '0 *20 I

40

I

80

I

120

160 m/e

I

I

I

200

240

280

I

I

I

I

I

I

I

13C NMR Spectrum (100.0 MHz, 020 solution)

I

1=~" proton'decoupled

178

ppm

176

L.a, J , I

I

I

I

200

I

I

I

I

120

160

lJJ

. I

I

40

80

It,

I

I

0

o(ppm)

1H NMR Spectrum (400 MHz. 020 solution)

H20 and HOO in solvent

Note: there are 3 protons which exchange with the 020 solvent

L expansions

""

II ,

,

4.7 ppm

4.9

358

I

I

10

9

~ ,

L

,

3.0 2.9 ppm

~

I

I

I

I

I

I

I

I

8

7

6

5

4

3

2

1

I

0

o(ppm)

Problem 269

100 80

1200

2000 1600 V (ern")

3000

4000

Mass Spectrum

84

43

800

-'" co

'" '"co

C-

60

No significant UV

102

l/l

absorption above 220 nm

.c

40 '0 ~ •• 0

126

144

20 I

I

120

80

40

l.

160

200

240

280

m/e

13C NMR Spectrum (100.0 MHz, D20 solution)

1H

120

160

200 NMR Spectrum

0

o(ppm)

H 20 and HOD in solvent

(400 MHz, D20 solution)

L

Note: there are 3 protons which exchange with the D20 solvent

I~

~ I'~ I

40

80

I

4.3 4.2

r-

,

i

i

2.4

2.2

2.1

1.9

J

,

ppm

-f

-

...-

J

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 359

Problem 270

IR Spectrum 3547

(KBr disc)

2000

3000

4000

1200

1600

800

V (crn'")

100

Mass Spectrum

107

80

UV Spectrum

192

-'"

'" Q)

o,

60

Q)

In

147

'"

.D

40 '0


20 40

120

80

200

160

280

240

m/e I

13C

I

I

I

I

I

I

I

I

I

I

J

NMR Spectrum

(100.0 MHz, COCI 3 solution)

DEPT

CH2

1CHA

CHt

solvent

L

/ proton-decoupied

I

I

I

II I

II

I

I

I

I

I

I I

I

I

I

"

120

160

200

80

o s (ppm)

40

expansions

1H NMR Spectrum

~~~A

(400 MHz, COCI3 solution) Note: there is a broad signal at 11.5 ppm (1 proton) which exchanges with 020

,

,

,

,

,

,

,

6.2

6.0

5.0

4.8

4.3

4.1

3.1

i

i

1.4

1.2 ppm

,

3.0 ppm

Exchanges with 020

1 TMS

10

360

9

8

7

6

5

4

3

2

1

o

() (ppm)

Problem 271

IR Spectrum (liquid film)

2851 1077

100 80

1600 2000 V (cm")

3000

4000

39

1200

800

Mass Spectrum

41

\.I

-'"


0.

60

M+"

Ql C/)

40

No significant UV

70


.D.

absorption above 220 nm

'0 ~. o

20

C 4H 6O

,II

40

120

80

160

200

240

280

m/e

13C

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

NMR Spectrum

(50.0 MHz, CDCI 3 solution)

~j

proton coupled

solvent m

proton decoupled

I

•

I

I

I

I

I

160

200

I

120

I

I

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

.---~

----'

-

TMS

I I

10

I

I

I

I

I

I

I

I

I

9

8

7

6

5

4

3

2

1

I

0

o(ppm) 361

Problem 272

IR Spectrum (liquid film)

1620

4000

2000

3000

1600

1200

800

V (crn'")

100 80

Mass Spectrum

41 -""

'"

39

Q)

a.

60

No significant UV

Q)


'"

absorption above 220 nm

.0

40 '0 0~

20 I

40

120

80

200

160

240

280

role I

I

I

I

I

I

I

I

I

I

I

I

13e NMR Spectrum (20.0 MHz. CDC'3 solution)

,......

off-resonance decoupled

1

.ljJ

~

-I"

TMS

/

solvent

i

/

III

proton decoupled I

I

I

I

160

200 1H

I

I

I

NMR Spectrum 25 Hz

I

~

I

I

80

120

(100 MHz, CDCI 3 solution)

I

I

~

I

i

6.27

4.90

I

4.25

2.55 ppm

362

J

JA

0 (ppm)

~~

I

.:

J

o

40

11

I

I

j

TMS

~U

i

I

I

I

I

I

I

I

I

I

10

9

8

7

6

5

4

3

2

1

o

o (ppm)

Problem 273

IR Spectrum (KBr disc)

1697

2000

3000

4000

1600

1200

800

V (crn")

100 80

Mass Spectrum

126

UV Spectrum

.>It.

'Co"

Amax 334 nm Amax 279 nm Amax 270 nm Amax 236 nm

Ql

60

Ql

''""

154

.0

40 15

M+" = 216 «

1%)

198

cf!..•

20

C 12H 804

(109101': 3.2) (109101': 3.7) (109101': 3.7) (109101': 4.8)

solvent: methanol

80

40

I

13C

I

120

160 m/e

I

I

I

240

200

I

I

280

I

I

I

I

I

NMR Spectrum expansion

(50.0 MHz. CDCliCD3S0CD3 solution)

'-J

DEPT

CH 2

1 CH

3t

CHt

solvent \.J V

.--'

proton decoupled I

I

I

200

I

I

130

ppm

I

I

,

I

160

"---

I

132.5 I

120

I

80

I

I

o s (ppm)

40

1H NMR Spectrum (200 MHz. CDCI 3 solution)

12

11

ppm TMS

10

9

8

7

6

5

4

3

2

1

o

() (ppm)

363

Problem 274a / A 400 MHz 1H NMR spectrum (with expansions and decouplings) is given on the following page

IR Spectrum (CHCI 3 solution)

4000

1200

2000

1600 V (crn")

3000

100

800

Mass Spectrum

80

0.0

0.5

-"

03

CIl Cl.

60

Q)

UV spectrum

M+'

l/l

03

203

.D

40 '0

1.0

0.224 mg /10 mls path length: 0.5 cm

;,'<

solvent: ethanol

20 '-----~

~ 40

__L..........J

80

~ 160

....L...

120

....L...

__L...

200

~ 240

__L...

280

1.5 u.... 200

......u

250

m/e

13C NMR Spectrum

A.

300 (nm)

350

12 lines

(20.0 MHz, CD 3SOCD3 solution)

off-resonance decoupled

TMS

2 resonances solvent

/ proton decoupled I

1H

120

160

200

80

o

40

0 (ppm)

NMR Spectrum

(100 MHz, CD 3SOCD3 solution) 50 Hz

3H

TMS

I

7.0 ppm 1H

2H

10

364

9

8

7

6

5

4

3

2

1

o

o(ppm)

Problem 274b

1H NMR Spectrum

1H

(400 MHz, CDCI 3 solution)

1H

Aromatic region only

1H 1H

1H

1H

Note: Irradiation of the signal at II 4.05 in the

1H NMR produces an enhancement of the signals at II 7.00 and 8.29 ppm via the NOE

8.6

8.2

-7.8

7.4

7.0

o (ppm) Expansion of regions of the 400 MHz NMR spectrum 20.0 Hz

8.291 ppm

8.631 ppm

7.760 ppm

8.353 ppm

7.612 ppm

7.002 ppm

365

Problem 275

1H NMR Spectrum I~

expansion

(400 MHz, CDCI 3 solution)

I-0---

r-r--

I

r-r-

,

I

,

8.0

----1 I

10

366

9

I 7.6

,

I

i

TMS

ppm

-II

-

I

I

I

I

I

8

7

6

5

4

I

3

2

1

o

o (ppm)

Problem 276

"\ IR Spectrum (liquid film)

4000

2000

3000

1600

1200

800

V (crn'")

100

Mass Spectrum

M+'

80

-" a>

60

a>

141

'"

UV Spectrum \I

156

Amax 321 nm Amax 281 nm

Q. V)

.a '"

40 '0

o~ '.

(10910£ 3.7)

solvent: ethanol

20

40

80

120

160 m/e

I

I

I

I

I

13C

(10910£ 2.6)

200

240

I

280

I

I

(50.0 MHz, CDCI 3 solution)

I

DEPT

CH2 ' CH 3t CHt

Resolves into two signals at higher field

I

I

,

I

I I

I

I

I

125

I

I

ppm

I

I

120

I

I

130

125

ppm

I

solvent I

160

200

I

130

~~1

---

proton decoupled I

I

I

~'",·"_lUL

NMR Spectrum

I

I

o

40

80

0 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution) expansion

I

8.0

7.0 ppm

TMS

10

9

8

7

6

5

4

3

2

1

o

o (ppm) 367

Problem 277

IR Spectrum (KBr disc)

4000

2000

3000

1200

1600

800

V (cm")

100 80

Mass Spectrum III

162/164

Q)

60

UV Spectrum

M+'

127

~

Amax 311 nm Amax 289 nm Amax 225 nm

0Q)

l/l

III

.0

40 '0 *20

Ll ,I ~,

I.

40

I

80

I

I

(10910c 2.6) ( 10910 c 3.7) (10 9101'; 5.0)

solvent: methanol

120

160 m/e

I

I

200

240

I

I

280

/' .

I

I

13C NMR Spectrum (50.0 MHz, CDCI 3 solution)

I

I

I

expansion

,

I

~

I

125 ppm

135

DEPT

CH 2

1 CHJ

CHt expansion

,

solvent

/

/

II

proton decoupled I

I

I

200

I

I

I

I

120

160

I

~

I

~j "'-,~/ ~.

I

I

I

125 ppm

135 I

I

I

I

o

40

80

8 (ppm)

1H NMR Spectrum (200 MHz, CDCI 3 solution)

expansion at 600 MHz

TMS

10

368

9

8

7

6

I

I

7.8

7.6

5

4

7.4

3

2

ppm

1

o

8 (ppm)

Chapter 9.1 Organic Structures from Spectra

Problem 278 An organic compound has the molecular formula ClOHl4" Identify the compound using the spectroscopic data given below. Y max (liquid film): no "'max: 265 (log E: 2.3)

significant features in the infrared spectrum. nm. IH NMR (CDC13 solution): 07.1, m, 5H; 2.5, apparent 'sextet, J 7 Hz, lH; 1.6, apparent quintet, J 7 Hz, 2H; 1.22, d, J 7 Hz, 3H; 0.81, t, J7 Hz, 3H ppm. I3C{IH} NMR (CDC13 solution): o~8.4 (C), 129.3, 127.9, 126.1, 42.3 (CH), 31.7 (CH 2), 22.2, 12.2 (CH 3) ppm. Ma~s spectrum: m/e 134 (M+·, 20)t 119(8), 105(100), 77(10).

Problem 279 An organic compound has the molecular formula C I2HI7NO. Identify the compound using the spectroscopic data given below.

(KBr disc): 3296m, l642s cm'. IH NMR (CDC13 solution): 07.23-7.42, m, 5H; 5.74, br s, exch. D 20 , lH; 5.14, q,J6.7 Hz, lH; 2.15, t,J7.l Hz, 2H; 1.66, m, 2H; 1.48, d,J6.7 Hz, 3H; 0.93, t,J7.3 Hz, 3Hppm. 13C{IH} NMR (CDC13 solution): 0 172.0 (C), 143.3 (C), 128.6, 127.3, 126.1,48.5 (CH), 38.8 (CH 2), 21.7 (CH 3), 19.1 (CH 2), 13.7 (CH 3) ppm. Mass spectrum: m/e 191(M+·, 40), 120(33), 105(58), 104(100), 77(18), 43(46). Y max

369

Chapter 9.1 Organic Structures from Spectra

Problem 280 An organic compound has the molecular formula C16H3004' Identify the compound using the spectroscopic data given below.

vmax (CHC13 solution): 1733 crrr". IH NMR (CDC13 solution): 84.19, q, J 7.2 Hz, 4H; 3.35, s, lH; 1.20, t, J7.2 Hz, 6H; 1.25-1.29, m, 10H; 1.10, s, 6H; 0.88, t, J 6.8 Hz, 3H ppm .. I3C{IH} NMR (CDC13 solution): 8168.5 (C), 60.8 (CH z), 59.6 (CH), 41.1 (CH z)' 36.3 (C), 31.8 (CH z), 29.9 (CH z), 25.1 (CH 3), 23.6 (CH z), 22.6 (CH z), 14.1 (CH 3), 14.0 (CH 3) ppm. Mass spectrum: m/e 286 (M+', 7...o t'24 1(25), 201(38), 160(100), 115(53).

Problem 281 An organic compound has the molecular formula CgH 13N0 3. Identify the compound .using the spectroscopic data given below. i

I

vmax (nujol mull): l690-l725s cm'. Amax : no significant features in the ultraviolet spectrum. IH NMR (CDC13 solution): 84.25, q, J 6.7 Hz, 2H; 3.8, t, J7 Hz, 4H; 2.45, t, J7 Hz, 4H; 1.3, t, J 6.7 Hz, 3H ppm. I3C{lH} NMR (CDC13 solution): 8207 (C); 155 (c); 62 (CH z); 43 (CH z); 41 (CH z); 15 (CH 3) ppm. Mass spectrum: m/e 171 (M+',15), 142(25),56(68),42(100).

370

Chapter 9.1 Organic Structures from Spectra

Problem 282 An organic compound has the molecular formula C IZH13N0 3 . Identify the compound using the spectroscopic data given below. v max (nujol mull): 3338, 1715, 1592 cm-'. Amax : 254 (log e: 4.3) nm. IH NMR (DMSO-d6 solution): 812.7, broad s, exch. DzO, lH; 8.42, d, J 6.1 Hz, 1H; 7.45-7.25, ,m,5H; 6.63 dd, J 15.9, 1.2 Hz, lH; 6.30, dd, J 15.9, 6.7 Hz, 1H; 4.93 ddd, J 6.7,6.1, 1.2 Hz, 1H; 1.90, s, 3H ppm. 13C{IH} NMR (DMSO-d6 solution): 8 171.9 (C), 169.0 (C), 135.9 (C), 131.7 (CH), 128.7 (CH), 127.9 (CH), 126.3 (CH), 124.6 (CH), 5'\;4 (CH), 22.3 (CH 3) ppm. Mass spectrum: m/e 219 (M+', 25), 175(10), 132(100), 131(94), 103(35), 77(46),43(83).

•

Problem 283 An organic compound has the molecular formula C 13HI60 4 . Identify the compound using the spectroscopic data given below. v max (KEr disc): 3479s, l670s, crn-'. Amax : 250 (log e: 4) nrn. IH NMR (CDC13 solution): 8 1.40, s, 3H; 2.00, bs exch., 1H; 2.71, d, J 15.7 Hz, 1H; 2.77, d, J 15.7 Hz, 1H; 2.91, d, J 17.8 Hz, 1H; 3.14, d, J 17.8 Hz, 1H; 3.79, s, 3H; 3.84, s, 3H; 6.80, d, J9.0 Hz, 1H; 6.98, d, J9.0 Hz, 1H ppm. 13C{IH} NMR (CDC13 solution): 8196.0 (c); 154.0 (C); 157.7 (C); 131.5 (c); 122.0 (C); 116.0 (CH); 110.5 (CH); 70.8 (C); 56.3 (CH 3) ; 55.9 (CH 3) ; 54.1 (CH z); 37.7 (CH z); 29.2 (CH 3) ppm. Mass spectrum: m/e 236 (M+', 87), 218(33), 178(100), 163(65).

371

-,

I

/

/

372

Chapter 9.2 The Analysis of Mixtures

9.2 THE ANALYSIS OF MIXTURES /

..

373

Chapter 9.2 The Analysis of Mixtures

Problem 284 A 400 MHz 'n NMR spectrum of a mixture of ethanol (C ZH60) 8 1.24,8 1.78,83.72 and bromoethane (CzHsBr) 8 1.68 and 8 3.44 is given below. Estimate the relative proportions (mole %) of the 2 components from the integrals in the spectrum.

ethanol

bromoethane

/

1 H NMR Spectrum (400 MHz, CDCI3 solution)

ppm

i

,/

I

I

5

4

'

•

I

i

••

Iii

3

••

Iii

I'

•

iii

I

•

2

Ii.

1

I

I

1.6

1.4

ppm

• I

ppm

I

pmpound ethanol

bromoethane

Mole %

II

I

.i

374

Chapter 9.2 The Analysis of Mixtures

Problem 285 A 400 MHz IH NMR spectrum of a mixture of common organic solvents consisting of benzene (C6H6) 8 7.37; diethyl ether (C 4H IOO) 8 3.49 and 8 1.22; and dichloromethane (CH 2Ch) 8 5.30 is given below. Estimate the relative proportions (mole %) of the 3 components from the integrals in the spectrum.

o

v

benzene

diethyl ether

dichloromethane

1H NMR Spectrum (400 MHz, CDCI 3 solution)

I

i

3.5

, .... , I

, I ....

8

7

6

'"

3.4 ppm

5

Compound

4

3

I

1.2

j

ppm

,....

I'

I

i

1.3

2

1

ppm

Mole %

benzene

diethyl ether

dichoromethane

375

Chapter 9.2 The Analysis of Mixtures

Problem 286 A 400 MHz IH NMR spectrum of a mixture of benzene (C6H6) 8 7.37, ethyl acetate (C4HgOZ) 8 4.13, 8 2.05, 81.26 and dioxane (C4H gO z) 8 3.70 is given below. Estimate the relative proportions (mole %) of the 3 components from the integrals in the spectrum.

c benzene

ethyl acetate

dioxane

NMR Spectrum (400 MHz, CDCI3 solution)

1H

/

'I

8

(

/

I

I

1

I

4.2

4.1

ppm

1.3

'

7

6

5

4

2

I

Compound

benzene

ethyl acetate

dioxane

376

1

1.2 ppm

Mole %

ppm

Chapter 9.2 The Analysis of Mixtures

Problem 287 A 100 MHz B C NMR spectrum ofa mixture of ethanol (CZH60) 8 18.3 (CH3), 8 57.8 (CHz) and bromoethane (CzHsBr) 8 19.5 (CH 3) and 8 27.9 (CHz) in CDCh solution is given below. The spectrum was recorded with a long relaxation delay (300 seconds) between acquisitions and with the NOE suppressed. Estimate the relative proportions (mole %) of the 2 components from the peak intensities in the spectrum.

ethanol

bromoethane

13C NMR Spectrum (100 MHz, CDCI3 solution)

solvent

III

I

100

80

60

Compound

.'"

I

40

20

ppm

Mole %

ethanol

bromoethane

377

Chapter 9.2 The Analysis of Mixtures

Problem 288 A 100 MHz B C NMR spectrum of a mixture of benzene (C6H6) 8 128.7 (CH), diethyl ether (C4H LOO) 8 67.4 (CH z) and 8 17.1 (CH 3) and dichloromethane (CHzCh) 8 53.7 in CDCh solution is given below. The spectrum was recorded with a long relaxation delay (300 seconds) between acquisitions and with the NOE suppressed. Estimate the relative proportions (mole %) of the 3 components from the peak intensities in the spectrum.

c

diethyl ether

benzene

dichloromethane

NMR Spectrum (100 MHz,'CDCI3 solution)

13C

solvent m

140

120

100

80

40

,/ I

Compound

benzene

diethyl ether

dichoromethane

378

Mole %

20

ppm

Chapter 9.2 The Analysis of Mixtures

Problem 289 A 100 MHz l3C NMR spectrum of a mixture of benzene (CJI6) 8 128.7 (CH), ethyl acetate (CH3CH20COCH3) 8 170.4 (C=O), 8 60.1 (CH2), 8 20.1 (CH3),8 14.3 (CH3) and dioxane (C4Hg02) 8 66.3 (CH 2) in CDC!) solution is given below. The spectrum was recorded with a long relaxation delay (300 seconds) between acquisitions and with the NOE suppressed. Estimate the relative proportions (mole %) of the 3 components . from the peak intensities in the spectrum.

o benzene

ethyl acetate

dioxane

13C NMR Spectrum . (100 MHz, CDCI3 solution)

\ 180

160

140

120

100

Compound

solvent"

I

80

60

40

20

ppm

Mole %

benzene

ethyl acetate

.. dioxane

379

Chapter 9.2 The Analysis of Mixtures

Problem 290 Oxidation of fluorene (C13HIO) with chromic acid gives fluorenone (C13HgO). If the reaction does not go to completion, then a mixture of the starting material and the product is usually obtained. The lH NMR spectrum below is from a partially oxidized sample of fluorene so it contains a mixture of fluorene and fluorenone. Determine the relative amounts (mole %) of fluorene and fluorenone in the mixture. H

H

H

H

o fluorene

fluorenone

lH NMR Spectrum (300 MHz, CDCI3 solution)

,/

/

;'

9.0

8.0

7.0

6.0

5.0

Compound

Mole %

fluorene

" f1uorenone

380

4.0

3.0

ppm

Chapter 9.2 The Analysis of Mixtures

Problem 291 Careful nitration of anisole (CH30C6HS) with a new nitrating reagent gives a mixture of 4-nitroanisole and 2-nitroanisole. The section of the I H NMR spectrum below is from the aromatic region of the crude reaction mixture which is a mixture of the 4- and 2-nitroanisoles. Determine the relative amounts of the two products in the reaction mixture from the integrals in the spectrum.

nitration

•

,'H NMR Spectrum (500 MHz, CDCI3 solution) rr:

, ,-

'. rr:

.--J

rr:

/

--'

.--J

'---'

I

I

i

I

8.0

7.6

7.2

6.8

Compound

ppm

Mole %

4-nitroanisole

2-nitr(!)anisole

381

\,

/

382

Chapter 9.3 Problems in 20 NMR

9.3 PROBLEMS IN 2-DIMENSIONAL NMR

383

Chapter 9.3 Problems in 20 NMR

Problem 292 The 'n and BC NMR spectra of l-propanol (C 3HgO) recorded in CDC!) solution at . 298K are given below. The 2-dimensionaI 1H)H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and then use the C-H correlation spectrum to assign the BC spectrum i.e. determine the chemical shift corresponding to each of the protons and each of the carbons in the molecule. 3

2

4

t-propanol

Proton

Carbon

Chemical Shift (0) in m

H1

C1

H2 ,

C2

H3

C3

Chemical Shift (0) in m

H4

1H NMR Spectrum (300 MHz, CDCI 3 solution)

-

,

Exchanges with 020

I

I

I

I

I

I

3.5

3.0

2.5

2.0

,

I

I

1.5

1.0

ppm

13C NMR Spectrum (75 MHz; CDCI 3 solution)

solvent m

384

I

I

I

I

80

60

40

20

I

o ppm

Chapter 9.3 Problems in 20 NMR

1H - 1H COSY Spectrum (300MHz, CDCI 3 solution)

----------i------------------------------- -~ ------- • . -----,

I

[,

1.0

'

:I

iI

,~::

!

-------.1t ----- -----------~-------- ------

~.------- ~, ,

------

, , ,I I ,I ,,I

,I I

,I ,,I ,I I ,I i

2.0

,I

,! i

-------

.

I

3.0

,I i I

/ ,:" ----------.------- . ------------------------------tlOI" • ,~

:

II

I

'

, I

I

1 I

I , I '

:

3.0

2.0

-~

i

ppm

1.0

C-H Correlation Spectrum

:

('H 300 MHz; l3C 75 MHz; CDCI 3 solution)

i

,

I

i

i

I

"

i

~'

- -- -- ----1------------------------------------;----------,

-------

I

i

I

I

:

I

l

I

---------i----------------------------- ---- II~~I ---------- L

10 20

_ 30

40

50 60

ill ---------------------------------- T -------- --ijr

!

70

I I I

i I :

-""

80

I

I

; 3.0

2.0

1.0

ppm

385

Chapter 9.3

Problems in 2D NMR

Problem 293 The IH and l3C NMR spectra of l-iodobutane (C4H9I) recorded in CDCl3 solution at 298K are given below. The IH spectrum contains signals at 83.20 (HI), 1.80 (H2), 1.42 (H3) and 0.93 (H4) ppm. The l3C spectrum contains signals at 86.7 (CI), 35.5 (C2), 23.6 (C3) and 13.0 (C4) ppm. On the facing page produce a schematic diagram of the COSY the C-H correlation spectra for this molecule showing where all of the cross peaks and diagonal peaks would be. ' 4

2

3

1-iodobutane

1H NMR Spectrum (400 MHz, CDCI 3 solution)

, I

3.5

I

I

3.0

2.5

'

I

I

2.0

1.5

'

i

1.0

ppm

/

13C NMR Spectrum (100 MHz, CDCI 3 solution) solvent

•

I 80

386

60

40

20

ppm

...

Chapter 9.3 Problems in 20 NMR

j ppm f-

-

1H -1H COSY Spectrum (400 MHz, CDCI 3 solulion) I

-l1

II

LI

I

I

I

,

I

I

I

I

1 1

I I

I I

1 1

_ _ _ _ _ _ _ ---!

I

I I

I

f

I

1 1 _ _ _ _ _ _ _ _ _1

I J1

1 11

1 1 .1

1

I

1

1

I

I

I

I

I

I

1 1I

\

I

I

I

I

1

1

1

1

1I

"I

1 1 ----- - 1 - --- - - -- --- -,--------- --- - --- -- - -- - -- --"-

_

1.0 V _

I ---,---- --- ---

1 1

2.0

I

I I I

I

I I

I

3.0 I I

I

- ------..., - - -- -- - - - - - - - - -- -- --- - - - -1- - - - -- -,-- - -- - - - - r- --- --- --1

1 I

I

1

1

1

I

I

I

I

I

I

I

I

I

1

1

1

I

1

I

I

I

I

I

I

3.0

I

2.0

-

I

I

1

1.0

1

ppm

, C-H Correlation Spectrum

1

(lH 400 MHz; 13C 100 MHz; CDCI 3 solulion)

I I

ppm

1

I

I I

I

I

i

I ________ 1

I

I

1

~

1

I

-'

.1

I

I

I

I

I

I

I

I

1

1

1

I

________ 1_-

o

I

t-

:

_

10

_

20

1 1 1 I ------- -:--------- ------- -------- --+------t---- ----.-j---------I

I

I

I

1

1

1

I

:I

:I

I

I

I

30

I

-------- i-----------------:-- --------~------~-- --- - -- ··1----------

:

iI

I

I

I

,

I

3.0

I

2.0

I

I

I

I

I

1

1.0

- 40

ppm

387

Chapter 9.3

Problems in 20 NMR

Problem 294 The lH and l3C NMR spectra ofisobutanol (2-methyl-l-propanol, C4H IOO) recorded in CDCh solution at 298K are given below. The IH spectrum contains signals at 83.28 (HI), 2.98 (OH), 1.68 (H2) and 0.83 (H3) ppm. The l3C spectrum contains signals at 869.3 (CI), 30.7 (C2) and 18.7 (C3) ppm. On the facing page produce a schematic diagram of the COSY the C-H correlation spectra for this molecule showing where all of the cross peaks and diagonal peaks would be.

/ isobutanol

1H NMR Spectrum

expa~jl

(300 MHz, CDCJ 3 solution)

~pa",;o,

I

Exchanges with D 20

+ 3.4

1.8

1.6 ppm

3:2 ppm

I

I

I

I

4.0

3.0

2.0

1.0

•

ppm

13C NMR Spectrum (75 MHz; CDCI 3 solution)

solvent m

388

I

I

I

I

80

60

40

20

I

o ppm

I I

Chapter 9.3 Problems in 20 NMR

u

j.

.111.

ppm

1H - 1H COSY Spectrum

I I

I

(300 MHz, CDCI 3 solution)

,

!I ,I

I

I

------------!-._--!--------------------!------------!--------I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

,I

I

I

I

I

I

I L

II

I L

I

I

I

I

I t

I I

I ___________ .I_.

"

I

,

I

,I

I

I

I

I

I

I

I

I

I

I

I

I

f-- --- - -- -_.-

-

j

I

\

I

I

I

2.0

I

I

i I

_

I

I

,I I

I

1.0

I

I

I

I

I

I

I

I

Il,

l,I I

iI

--!----~----- - --------- --- --!--- - - --- ----!- --- ----I t I I

I ___________.'-. I

t

I

i

I

I

I

I

I

I

,

f

I

7

I

-

I

I

I

I I

I

:

3.0

_

l-t

3.0

4.0

U

ppm

1.0

2.0

j

.dl.

ppm

C-H Correlation Spectrum (1

H 300 MHz, 13C 75 MHz; CDCI 3 solution)

I

I

------------i-----j ----------------------~--------------:----------20 •

t

I

i

.

I

----------- :-----1 ,

,

I

I

l

J

I

I

I

--------------------1------------

I !----------

I

I

40

:

~ I

!I

I

I

:

I

I

60

i

i I I ------ -- --- r-- ---1---- - --- -- - -- - -- -- --- r--- ----- ------i------- --.

: ,

3.0

: I

2.0

:' I

:

I

I

I

1.0

80

ppm

389

Chapter 9.3 Problems in 20 NMR

Problem 295 The lH spectrum of3-heptanone (C7H I40) recorded in C6D6 solution at 298K at 500 MHz is given below. The1H spectrum has signals at (50.79,0.91, 1.14, 1.44, 1.94 and 1.97 (partly overlapped) ppm. The 2-dimensional lH)H COSY spectrum is given on the facing page. From the COSY spectrum, assign the proton spectrum i.e. determine the chemical shift corresponding to each of the protons in the molecule. 2

3

4

6

5

7

v

3-heptanone

\

,.

(

/

r

I

I

I

I

2.4

2.0

1.6

1.2

0.8

Proton

ppm

Chemical Shift (0) in ppm

H1 H2

,,:;;\n>,.',;;:,.. . . . ~;. •. . fiJD' H4

'5;i,;;~

··d'.'·

H5 H6 H7

\

390

;

~K;. \.:'. c.;';;;.;;;.!,;

.·!iJ,~;."'!i}~; "'

;"

;-F;";;; ..,

Chapter 9.3 Problems in 20 NMR

IH

COSY spectrum of3-heptanone (recorded in C 6D6 solution at 298K, at 500 MHz).

2

3

4

5

6

7

391

Chapter 9.3 Problems in 20 NMR

Problem 296 The IH and l3C NMR spectra of 8-valerolactone (C SHg02) are given below recorded in C6D6 solution at 298K, at 600 MHz. The I H spectrum has signals at 8 1.08, 1.16,2.08, and 3.71 ppm. The l3C spectrum has signals at 819.0,22.2,29.9,68.8 and 170.0 ppm. The 2-dimensional IH_1H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and use this information to assign the l3C spectrum. 3

:0; a a

o-valerolactone

,

\

1H NMR Spectrum (600 MHz,

,.---

c.o, solution)

,---

-

~

\J

I

I

I

I

I

I

3.5

3.0

2.5

2.0

1.5

1.0

ppm

solvent

+

13 C NMR Spectrum (150 MHz, CeDe solution)

I

/

/

J

I 180

Proton

160

Chemical Shift (0) in ppm

C) ••••

. " ' : , ' Ir?i:i i i i

H2 H3 H4 HS

392

100

120

140

0'

,c,:, ,i{ii"

"',); .,,; i'c:~

c,':

:ic:~',:;

80

Carbon

C1 C2 C3 C4 CS

60

40

20

ppm

Chemical Shift (8) in ppm

Chapter 9.3 Problems in 20 NMR

1H -1H COSY Spectrum (600 MHz, Benzene-Dg solution)

+

1.0

2.0

1-

3.0

40

60

4.0

3.0

2.0

1.0

ppm

393

Chapter 9.3 Problems in 20 NMR

Problem 297 The IH and BC NMR spectra of l-bromobutane (C4H9Br) are given below. The IH spectrum has signals at 8 0.91, 1.45, 1.82, and 3.39 ppm. The BC spectrum has signals at 813.2,21.4,33.4 and 34.7 ppm. The 2-dimensional 1H)H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, deduce the assignment of the proton spectrum and use this information to assign the B C spectrum. 4

2

3

1-bromobutane Proton

Carbon

Chemical Shift (8) in ppm

H1 H2 H3 H4

Chemical Shift (8) in ppm

C1 C2 C3 C4

.

lH NMR Spectrum (400 MHz, CDCI, solution)

i i i

I

3.4

ppm

1.8

1.6

1.4

i

i

1.2

t.e

ppm

/ I,.........~~,.........~~,.,.....,~~,..,...,-~~,..,...,-~~,..,...,-~~,..,...,-~~,......~~.,--r~~.,--r~~.,--r~ i

9

(

8

7

6

5

4

3

ppm

2

13C NMR Spectrum (100 MHz, CDCI, solution)

DEPT

CH,. CH,t CHt

•

I

proton decoupled

120

394

80

40

o

ppm

3.0

--

4.0

I

3.0

2.0

1.0

ppm

395

Chapter 9.3 Problems in 20 NMR

Problem 298 The I H and B C spectra of 3-octanone (C gH I 60) recorded in C 6D6 solution at 298K at 600 MHz are given below. The I H spectrum has signals at 8 0.82, 0.92, 1.11, 1.19, 1.47, 1.92 and 1.94 (partly overlapped) ppm. The B C spectrum has signals at 8 7.8, 14.0,22.7,23.7,31.7,35.4,42.1 and 209.0 ppm. The 2-D lH_1H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and use this information to assign the B C spectrum. 234

6

5

7

8

3-octanone

1H NMR Spectrum (600 MHz, Benzene-Dg solution)

I

I

I

I

I

I

I

2.0

1.8

1.6

1.4

1.2

1.0

0.8

~

ppm

r -.-- solvent

13c NMR Spectrum (150 MHz, Benzene·D6 solution)

I

/

I I

220 Proton

':y:

200

180

160

140

120

Chemical Shift (8) in ppm

100 Carbon

H1

C1

H2

C2

':1,\· 1\::0',",:'

:; .';;

;;0,,,;

.::~:{

;(iF ,;;:;/':3>;:('\\~;'';J!!,~I'~ '; T,· '; ';,oj;',,"':;;

C3

H4

C4

H5

C5

H6

C6

H7

C7

H8

C8

396

80

60

40

20

ppm

Chemical Shift (8) in ppm

Chapter 9.3 Problems in 20 NMR

1 1H - 1H

~

Jh.

ppm

COSY Spectrum

(SOO MHz, Benzene-Os solution)

#

--

If

~

••

0,8

1.0

1.2

V 1.4

I

$.1; 1.6

2.0

•

=

11 1.8

1.6

1.4

1.2

10

0.8

1.8

2.0

ppm

C-H Correlation Spectrum ('HGml'MHz; 13 e 150MHz; Benzene-Os solution)

10

20

30

40

2.0

1.8

1.6

1.4

1.2

1.0

0.8

ppm

397

Chapter 9.3 Problems in 20 NMR

Problem 299 The 'H and 13C NMR spectra of diethyl diethylmalonate (C UHZ0 0 4 ) recorded 298K in CDCh solution are given below. The 'H spectrum has signals at 8 0.76, 1.19, 1.88 and 4.13 ppm. The 13C spectrum has signals at 8 8.1, 14.0,24.5,58.0,60.8 and 171.9 ppm. The 2-dimensional'H-'H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and use this information to assign the 13C spectrum. c b a COOCH 2CH3

d

diethyl diethylmalonate

fl

e

9

V

h

CH 3CH2-C-CH2CH3

I

COOCH 2 C H3 j

Proton

Chemical Shift (3) In m

Carbon

, Ha

Ca

Hb

Cb Cc

.

Chemical Shift (3) in m

Cd Ce Cf Cg Ch

/

I

k

Cj Cj Ck

I

1H NMR Spectrum

=:f~

(300 MHz, CD_C_13_S0_lu_ti_on_)

I '

I '

I

4.0

I "

2.0

3.0

li I""

1.0

I

ppm

13C NMR Spectrum (75 MHz, CDCI3 solution)

solvent

I

I

I I

180

398

140

100

60

20

ppm

Chapter 9.3 Problems in 20 NMR

~ I

~ I

I

I

,.

1H - 1H COSY Spectrum (300 MHz, CDCI3 solution)

U

ppm

I

+

~

1.0

• •

2.0

3.0

4.0

4.0

3.0

C-H Correlation Spectrum

I

I

2.0

1.0

ppm

,

('H 300 MHz; 13C 75 MHz; CDCI3 solution)

20

40

60

4.0

3.0

2.0

1.0

399

Chapter 9.3

Problems in 20 NMR

Problem 300 The IH and 13C NMR spectra of butyl ethyl ether (C6HI40) recorded at 298K in CDCb solution are given below. The IH spectrum has signals at 80.87, 1.11, 1.36, 1.52,3.27 and 3.29 (partly overlapped) ppm. The B C spectrum has signals at 8 13.5, 15.0, 19.4, 32.1,66.0 and 70.1 ppm. The 2-dimensional 1H- IH COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and use this information to assign the B C spectrum. abc

Carbon

Chemical Shift (0) In ppm

-.

f

Chemical Shift (0) in ppm

Ca Cb Ce Cd Ce Cf

H~

Hb He Hd He HI

e

C~-C~-O-C~-C~-C~-C~

butyl ethyl ether

Proton

d

"-

\

1H NMR Spectrum (500 MHz, Benzene-D6 solution)

if I

I

I

3.0

2.0

1.0

ppm

13C NMR Spectrum (125 MHz, Benzsne-Dg solution)

80

400

60

40

20

ppm

Chapter 9.3 Problems in 20 NMR

I

ppm

I

1H - 1H COSY Spectrum

.

(500 MHz, Benzene-Ds solution)

1.0

-. ~"

It

.11.0

2.0

3.0

3.0

\

2.0

1.0

ppm

ppm

C-H Correlation Spectrum ('H 500 MHz; 13C 125 MHz; Benzene-Dg solution)

-

10

•

1f

20

30

40

50

-

60

.

•

70

3.0

2.0

1.0

ppm

401

Chapter 9.3 Problems in 20 NMR

Problem 301 The lH and l3 C NMR spectra of butyl butyrate recorded at 298K in C6D6 solution are given below. The lH spectrum has signals at 8 0.75,0.79 (partly overlapped), 1.19, 1.40, 1.52,2.08 and 3.97 ppm. The l3C spectrum has signals at 8 13.9 (2 overlapped resonances), 19.0, 19.5,31.2,36.2,64.0 and 172.8 ppm. The 2-dimensional 1H- I H COSY spectrum and the C-H correlation spectrum are given on the facing page. From the COSY spectrum, assign the proton spectrum and use this information to assign the l3 C spectrum. a

butyl butyrate

b

e

d

9

CH3 - CH 2 - CH 2 - CH 2 - 0 - C - CH 2 - CH 2 - CH3 II

o Proton

Carbon

Chemical Shift (8) in ppm

Ha Hb He Hd

Ca Cb Ce Cd Ce Cf Cg Ch

»<;

""A'

h!]

,i·,{C,.'~:M!;~~,,:1·..t1;~~tl~i

Hf Hg Hh

Chemical Shift (8) in ppm

,

I

1H NMR Spectrum (500 MHz, Benzene-Dg solution)

I

I

I

I

5.0

4.0

3.0

2.0

ppm resolves into 2 signals at higher field

13C NMR Spectrum

•

(125 MHz, Benzene-Os solution)

r

'l---

solvent

I 180

402

160

140

120

100

80

60

40

20

ppm

Chapter 9.3 Problems in 20 NMR

.

1H _1H .COSY Spectrum (500 MHz, Benzene-DS solution)

., -

ppm

1.0

. ., "• •• ,Ill

2.0

'.-

3.0

4.0

4.0

2.0

3.0

~

j

1.0

!A

J.

ppm

'--

ppm

C-H Correlation Spectrum ('H 500 MHz; 13c 125 MHz; Benzene-DS solution) 10

-

+ """ --=-=

•

.....

20

30

40

50 60

+ 70

4.0

3.0

2.0

1.0

ppm

403

Chapter 9.3 Problems in 20 NMR

Problem 302 The IH NMR spectrum of a mixture of l-iodobutane and l-butanol recorded at 298K in CDCh solution is given below. There is some overlap between the spectra of the components of the mixture. The TOCSY spectrum and the COSY spectrum are given on the facing page. Use the TOCSY and COSY spectra to determine the chemical shifts of all of the protons in I-butanol and l-iodobutane. 4

3

2

4

3

2

1-iodobutane

1-butanol

1H NMR Spectrum

,

(500 MHz, Benzene-De solution)

/

Exchanges with O 2

°

I

I

I

3.0

2.0

1.0

ppm

/

1-iodobutane

1-butanol

1H Chemical Shift (8)

in ppm H1

H2

H2

. H3

H3

H4

H4

.'j.;} ,:--.',' "Y£;;'{' li'\y">

404

in ppm ...!'

H1

;'::»

1H Chemical Shift (8)

··:i·, ~:;~i!;;;'<

-OH

Chapter 9.3 Problems in 20 NMR

~Lppm 'H TOCSY Spectrum (500 MHz, CeDe solution)

•

•

II

I

..

•

•

II

... 11 .. II

• II

fl. t

1.0

I 18

II

2.0

•

18

III

..... 2.0

3.0

•

1.0

3.0

ppm

~ 'H -'H COSY Specrtum (SOO MHz, CeDe solution)

.. ., ., . ••

.....,+

1.0

-

2.0

. 3.0

• 3.0

2.0

1.0

ppm

405

Chapter 9.3 Problems in 20 NMR

Problem 303 The (E)- and (Z)-isomers of2-bromo-2-butene (C4H7Br) are difficult to distinguish by IH NMR spectroscopy. Both isomers have 3 resonances (one between 5.5 and 6.0 ppm, -CH==C; one between 2.0 and 2.5, -CCfuBr; and one between 1.5 and 2.0 ppm, -CHCfu). In principle, the isomers could be distinguished using a NOESY spectrum. On the schematic NOESY spectra below, draw in the strong peaks (diagonal and off-diagonal) that you would expect to see in the spectra of (E)-2-bromo-2-butene and (Z)-bromo-2-butene.

LL

1

-

! " I

-,

p pm

!I

/' !i

-----_.- -;.------- -- ------_._----------,- -------------------:._--- ----:------

, :

,

'

_______ 1

.

.

l i

i

~.------,----.-.

.

i

j I

I

!

1H NOESY spectrum of (E)-2-bromo-2-butene, (300 MHz in CDCI 3 solution)

:

! !

1

2.0

1

i

4.0

I i .... ------.-;---,. ------- -----,-- ----------------·-----·-------j-------T----,

6.0 !

/

: 2.0

4.0

6.0

i

j

i ppm

/

1

ppm

i ~

I

I

•

I

'

I

._------ - -+_._---- - -----_._- --------_._----_._---_._---_.~- -----+..---- --

! ! -.! ----. -_._- -t-------·------- ----------- - -----·~----·------i- -----.f-

2.0

(Z)-2-bromo-2-butene, (300 MHz in CDCI 3 solution)

,I

4.0

.------- -t-·----- -------'-----------.- -----------------1- -----t------,-. I

6.0

406

4.0

I

I

i

i

2.0

1H NOESY spectrum of

6.0 ppm

Chapter 9.3 Problems in 20 NMR

Problem 304 The I H NMR spectrum of one stereoisomer of 3-methylpent-2-en-4-yn-l-ol l [HC= CCCH3)C=CHCHzOH] is given below. The 2-dimensional H NOESY spectrum is also given. Determine the stereochemistry of the compound and draw a structural formula for the compound indicating the stereochemistry. 1H NMR Spectrum (300 MHz, CDCI 3 solution)

Exchanges with 020

Expansion

Expansion

I

t

I

~

4.2 ppm

4.4

, I ' ,

, I

6.0

4.0

5.0

, , I

I ' , ,

3.0

2.0

ppm

1H _1H NOESY Spectrum (300 MHz, CDCI 3 sotution)

ppm

+-

•

fj

2.0

- 3.0

•

- 4.0

f--

.,.,. f--

-

f--

- 5.0

l-

-

f--

lD

6.0

•

t 5.0

4.0

3.0

- 6.0

2.0 ppm

407

Chapter 9.3 Problems in 20 NMR

Problem 305 The 'n NMR spectrum of l-nitronaphthalene recorded at 298K in CDC!) solution is given below. The 2-dimensional 1H NOESY spectrum is given on the facing page. Given that the nitro group at position 1 will always extensively deshield the proton at position 8 such that it will appear as the resonance at lowest field in the spectrum, use the NOESY spectrum to assign all of the other protons in the spectrum. He

N0 2

H7~H2

1-nitronaphthalene

H6~H3 Hs

H4

1H NMR Spectrum (400 MHz, CDCI 3 solution)

solvent residual

• -----'

'------'

I

!

8.8

1

'---' '-----'

i

8.6

8.4

8.2

8.0

7.8

I

I

i

7.6

7.4

7.2

;'

Proton

H2 H3 H4 H5 H6 H7 H8

408

Chemical Shift (8) in ppm

~

8.56 . . .

ppm

Chapter 9.3 Problems in 20 NMR

IH NOESY spectrum of l-nitronaphthalene (recorded in CDCh solution at 298K at 400 MHz). !

,..

1H -1H NOESY Spectrum

ppm

(400 MHz; CDCI, solution)

7.4

•

.

,.

7.6

••,.

J

n

•

.~

fl

~.

7.8

8.0

na

II

8.2

III

8.4

8.6

8.6

8.4

8.2

8.0

7.8

7.6

7.4

ppm

\.,

409

Chapter 9.3 Problems in 20 NMR

Problem 306 Use the basic spectral data plus the COSY and C-H correlation spectra on the facing page to deduce the structure of this compound.

IR Spectrum (liquid film)

1740

4000

2000

3000

1600

1200

800

V (cm")

100 80

143

Mass Spectrum

160

0.5

73

.><

60

~ c:

€'" o .0 '"

'" Q)

Co Q) CJ)

UV spectrum

1.0 r- '"

'"

.0

40 '0

~

44.1 mg I 10 mls path length: 0.1 cm solvent: ethanol

M+·

20

188

r

40

80

120

200

160

250

m/e I

13C

I

I

I

I

I

I

I

I

300

350

A (nm)

I

I

NMR Spectrum

(100 MHz, CDCI 3 solution)

DEPT

I

CH 2 • CH3t CHt

I

proton decoupled

120

160

200

80

o

40

~

(ppm)

lH NMR Spectrum (300MHz, CDC'3 solution)

TMS

5

4

410

3

2

1

~

o

(ppm)

Chapter 9.3 Problems in 20 NMR

.w.

L___

ppm

1H _1H COSY Spectrum (300 MHz, CDCI 3 solution)

1.0

2.0

3.0

4.0

4.0

3.0

2.0

1.0

ppm

ppm

C-H Correlation Spectrum .( 1 H

300 MHz; 13C 75 MHz; CDCI3 solution)

ttl 20

40

III 60

lilt

"80 4.0

3.0

2.0

1.0

ppm

411

Chapter 9.3 Problems in 20 NMR

Problem 307 Use the basic spectral data plus the COSY and C-H correlation spectra on the facing page to deduce the structure of this compound. IR Spectrum 1740

(liquid film)

4000

2000

3000

1200

1600

800

V (crn'") 100 80

"''""

Mass Spectrum

57

56

a5

41

Q)

c.

60

No significant UV

29

Q)

'" '"

absorption above 220 nm

.<:J

40

a

....

M+'

20 1.1

158 < 1%

,~ I

40

120

80

160

240

200

280

mle 13C NMR Spectrum (125 MHz, c,c, solution).

m solvent

//proton decoupled

....------r-

I

13.5 13.0 ppm

1H

120

160

200

80

o

" 40

0 (ppm)

expansion

NMR Spectrum

(500 MHz, CsD s solution)

, 4.1

4.0

j

I

2.2

2.1

J

, 1.6

1.4

1.2 ppm

i

0.9

I

0.8 ppm

'\MS 5

412

4

3

2

1

o

o(ppm)

Chapter 9.3 Problems in 20 NMR

~ I

I

1H -1H COSY Spectrum (500 MHz, CDCI3 solution)

f-

. +-

I

..... .....

4t-

.

ppm

I

1.0

2.0

f-

3.0

f-

r

•

+

4.0

4.0

3.0

I

C-H Correlation Spectrum ('H 500 MHz; 13c 125 MHz; CDCI3 solution)

I

4.0

I

I

3.0

I

I

2.0

Chapter 9.3 Problems in 20 NMR

Problem 308

IR Spectrum

1001

(liquid film)

4000

2000

3000

Use the basic spectral data plus the COSY and NOESY spectra on the facing page to deduce the structure, including stereochemistry of this compound.

1200

1600

800

V (em")

100

Mass Spectrum 41

69

80 "'"

'" Q)

a.

60

U)

40

'" '0

No significant UV

Q)

, absorption above 220 nm

.D

~

20

M+"

136

~,

,II., 40

Illl

I,

80

120

154

I

200

160

240

280

I

I

m/e I

I

I

I

I

I

I

I

I

13C NMR Spectrum (125 MHz, CDCI, solution)

DEPT CH2 • CH,t CHt

I

I~

~r61on decoupled lI

I

I

160

200

~,-u

120

80

40

.

r-

~

1-;-

exchanges with D 2 0

expansions

., i :, » , , , , 5,2

,

, 4,2

5,0

,

,

-.J~

4.0

,

r--

SI

1 ,

,

2.0

~

r-

,

1.8

,

, 1,6

, ppm

-

---./

~

A

_A

I

I

6

5

414

o(ppm)

0

expansion

coa, solution)

5,4

lL I

1H NMR Spectrum (500 MH<,

I

I

4

3

2

o(ppm)

-

~-

.._-

-+-+

.

..

t

4.0

!

5.0

•

0

i

I'

•

0

I

!

6.0

6.0

5.0

4.0

3.0

2.0

1.0

ppm

415

Chapter 9.3 Problems in 20 NMR

Problem 309 Use the basic spectral data plus the COSY and NOESY spectra on the facing page to deduce the structure, including stereochemistry of this compound.

1669

IR Spectrum (liquid film)

2000

3000

4000

1002

1600

800

1200

V (cm-1 )

100

Mass Spectrum 69

80 ""
41

No significant UV

'" '"


absorption above 220 nm

.0

40 'l5 #.

1

20

120

80

40

154

",.II,

,iJ

,IL

M+' 136

160

200

240

280

mle I

I

I

I

I

I

r

I

I

I

13C NMR Spectrum (125 MHz, CDCI 3 solution)

DEPT

CH 2

1CH3t

CHt

II

I

\

/

/proto~

LLI

decoupled

I I

I

I

I

I

UL I

I

160

200

solvent m

I

120

80

40

0

o(ppm)

1H NMR Spectrum (500 MHz. CDCI 3 solution)

expansion

~~I'"

,5.4

5,3 5,1

5,0

4,1

5

6

416

, 4,0

2,4

2,2

4

2.0

1,8

3

2

o(ppm)

Chapter 9.3 Problems in 20 NMR

ppm

1H -1H COSY Spectrum (500 MHz, CDCI, solution)

..

... # 2.0

3.0

+

..

4.0

5.0

t·

6.0 6.0

5.0

4.0

ppm

2.0

3.0

~

1H -1H NOESY Spectrum

ppm

.. 11

(500 MHz. CDCI, solution)

. .

~

2.0

I,

3.0

+

..

4.0

++

5.0

to

"

• 60

60

5.0

4.0

3.0

2.0

ppm

417

/

/

/

Chapter 9.4 NMR Spectral Analysis

9.4 NMR SPECTRAL ANALYSIS

419

Chapter 9.4 NMR Spectral Analysis

Problem 310 Give the number of different chemical environments for the magnetic nuclei IH and l3C in the following compounds. Assume that any conformational processes are fast on the NMR timescale unless otherwise indicated. Structure

Number of 1H environments

CH3- CO- CH2CH2CH3 CHaCH2 - CO - CH2CHa CH2=CHCH2CH3 cis- CH3CH=CHCH3 trans-CH 3CH =CHCH3

0 Q-CI

c:

Br

CIUCI

,

~I

I

Br-o-Br

Br-o-CI CH3 C'UO

~I

r;:J r;:J

cdc, H

420

Assuming slow chairchair interconversion Assuming fast chairchair interconversion Assuming the molecule to be conformationally rigid

<-

Number of 13C environments

Chapter 9.4 NMR Spectral Analysis

Problem 311 Draw a schematic (line) representation of the pure first-order spectrum (AMX) corresponding to the following parameters: v A = 300; vM = 240;

Frequencies (Hz from TMS):

Yx

= 120.

JAM = 10; JAX = 2; J MX = 8. Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities of lines that would be apparent in a "real" spectrum. \I Coupling constants (Hz):

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 60 MHz for protons.

I

350

I

I

300

250

I

I

200

I

I

150

100

i

I

(Hz from TMS)

421

;g,,9.-. .

Chapter 9.4 NMR Spectral Analysis

Problem 312 Draw a schematic (line) representation of the pure first-order spectrum (AMX) corresponding to the following parameters:

= 180; v M = 220; Yx = 300. JAM = 10; JAX = 12; JMX = 5.

Frequencies (Hz from TMS):

vA

Coupling constants (Hz):

Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities oflines that would be apparent in a "real" spectrum. (a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants. .

\

(b)

/

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 200 MHz for protons.

/

(

I

350

422

300

250

200

I

i

150

100

I

j

(HZ from TMS)

"CW

;,,'

Chapter 9.4 NMR Spectral Analysis

Problem 313 Draw a schematic (line) representation of the pure first-order spectrum (AX2) corresponding to the following parameters:

= 150;

Frequencies (Hz from TMS):

VA

Coupling constants (Hz):

J AX = 20.

Yx

= 300.

Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities of lines that would be apparent in a "real" spectrum.

v

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 0 scale corresponding to the above spectrum obtained with an instrument operatingat 400 MHz for protons.

I

350

i

I

300

I

i

250

200

I

I

150

I

I

I

100

I

I

(Hz from TMS)

423

Chapter 9.4 NMR Spectral Analysis

Problem 314 A 60 MHz IH NMR spectrum of diethyl ether is given below. Note that the spectrum is calibrated only in parts per million (ppm) from tetramethylsilane (TMS), i.e. in 8 units.

I

/

(a)

Assign the signals due to the -CH z- and -CH 3 groups respectively using three independent criteria (the relative areas of the signals, the multiplicity of each signal and the chemical shift of each signal).

(b)

Obtain the chemical shift of each group in ppm, then convert to Hz at 60 MHz from TMS (see Section 5.4).

(c)

Obtain the value of the first-order coupling constants

(d)

Demonstrate that first-order analysis was justified (see Section 5.6).

3JH_H

(in Hz).

/

TMS

3.0

2.0

1.0

0.0 D ppm from TMS

424

Chapter 9.4 NMR Spectral Analysis

Problem 315 A 100 MHz 1H NMR spectrum of a 3-proton system is given below.

(a)

. (b)

Draw a splitting diagram and analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement. Justify the use of a first-order analysis (see Section 5.6).

1H 500

450

400 (Hz from TMS)

425

Chapter 9.4 NMR Spectral Analysis

Problem 316 Portion of the 60 MHz NMR spectrum 2-furoic acid in CDCb is shown below. Only the resonances due to the three aromatic protons (HA , HM and Hx) are shown.

HM HA

'

h

Hx

0

2-Furoic Acid

COOH

(a)

Draw a splitting diagram and analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(b)

Justify the use ofa first-order analysis (see Section 5.6).

Note: This is a 60 MHz spectrum.

,

/

I

I

460

426

440

420

400

I

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 317 A portion of the 100 MHz 'H NMR spectrum of 2-amino-5-chlorobenzoic acid in CD 30D is given below. Only the resonances due to the three aromatic protons are shown.

(a)

Draw a splitting diagram and analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (0 in ppm) by direct measurement.

(b)

Justify the use of a first-order analysis (see Section 5.6).

(c)

Assign the three multiplets to H 3, H4 and H 6 given:

780

•

the characteristic ranges for coupling constants between aromatic protons (see Section 5.7);

•

the fact that H 3 will give rise to the resonance at the highest field due to the strong influence of the amino group (see Table 5.6).

760

i

I

740

720

700

680

(HZ from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 318a Portion of 100 MHz IH NMR spectrum of methyl acrylate (5% in C6D6) is given below. Only the part of the spectrum containing the resonances of the olefinic protons HA> HB and He is shown.

HA

" C=C "-

COOCH3

/

HB

/

He

methyl acrylate (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(c)

Justify the statement that "this spectrum is really a borderline second-order (strongly coupled) case". Point out the most conspicuous deviation from first-order character in this spectrum (see Section 5;6).

(d)

Assign the three multiplets to H A , HB and He on the basis of coupling constants only (see Section 5.7).

/

I

640

428

620

600

580

560

540

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 318b This is the computer-simulated spectrum corresponding to the complete analysis of the spectrum shown in Problem 3l8a, i.e. an exact analysis in which first-order assumptions were not made. The simulated spectrum fits the experimental spectrum, verifying that the analysis was correct. Compare your (first-order) results from Problem 318a with the actual solution given here. Number of SPINS F(1) F(2) F(3)

=

J(1,2) J(1,3) J(2,3)

= + 10.539 Hz = + 1.589 Hz = + 17.278 Hz

3 = + 528.500 Hz = + 594.531 Hz = + 626.093 Hz

START of simulation = + 750.000 Hz FINISH of simulation = + 500.000 Hz LINE WIDTH = + 0.427 Hz

'---~

"----.J '----' '----" '--

i

i

i

640

620

600

580

--'

560

540

(Hz from TMS)

429

Chapter 9.4 NMR Spectral Analysis

Problem 319 Draw a schematic (line) representation of the pure first-order spectrum (AX3) corresponding to the following parameters: 160;

Frequencies (Hz from TMS):

VA =

Coupling constants (Hz):

J AX = 15.

Vx =

280.

Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities oflines that would be apparent in a "real" spectrum.

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 60 MHz for protons.

/

I

350

430

i

I

I

I

300

250

I

I

200

150

I

Iii

100

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 320 A 100 MHz IH NMR spectrum of a 4-proton system is given below. (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(c)

Justify the use of first-order analysis (see Section 5.6).

3H

1H I

200

150

100

(Hz from TMS)

431

Chapter 9.4 NMR Spectral Analysis

Problem 321 Draw a schematic (line) representation of the pure first-order spectrum (AMX 2) corresponding to the following parameters: Frequencies (Hz from TMS):

VA =

Coupling constants (Hz):

JAM = 10; J AX = 2; J MX = 6.

340; vM

=

240;

Yx =

100.

Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities of lines that would be apparent in a "real" spectrum.

/ ;'

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 60 MHz for protons.

"

I

350

432

300

250

i

I

200

I

,

150

i

I

I

100

I

I

(Hz from TMS)

,.

Chapter 9.4 NMR Spectral Analysis

Problem 322 Draw a schematic (line) representation of the pure first-order spectrum (AM 2X) corresponding to the following parameters: Frequencies (Hz from TMS):

VA

= 110; vM = 200;

Yx

= 290.

JAM = 10; J AX = 12; J MX = 3. Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities oflines that would be apparent in a "real" spectrum. V Coupling constants (Hz):

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which splittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 60 MHz for protons.

I

350

300

,

I

250

200

I

I

150

I

100

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 323 A 100 MHz IH NMR spectrum ofa 4-proton system is given below. (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(c)

Justify the use of first-order analysis (see Section 5.6).

/

Jl

2H

1H

~L 1H I

600

434

500

400

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Prob\em 324 A 100 MHz 'H NMR spectrum of a 4-proton system is given below. (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(c)

Justify the use of first-order analysis (see Section 5.6).

2H

1H

1H

i

300

JlL

I\J

\. I

250

200

I

I

150

100

50

(Hz from TMS)

435

Chapter 9.4 NMR Spectral Analysis

Problem 325 A 100 MHz IH NMR spectrum of a 4-proton system is given below. (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (0 in ppm) by direct measurement.

(c)

Justify the use of first-order analysis (see Section 5.6).

v

/

/

I

J

1H j

300

436

i

i

250

200

150

100

50

(Hz from TMS)

Chapter 9.4 NMR Spectral Analysis

Problem 326 A 200 MHz 'H NMR spectrum of a 5-proton system is given below. (a)

Draw a splitting diagram.

(b)

Analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (0 in ppm) by direct measurement.

. (c)

Justify the use of first-order analysis (see Section 5.6).

2H

2H 1010

990

Hz from TMS

510

1H I

I

490

110

Hz from TMS

90

Hz from TMS

437

Chapter 9.4 NMR Spectral Analysis

Problem 327 Portion of 100 MHz NMR spectrum of crotonic acid in CDC13 is given below. The upfield part of the spectrum, which is due to the methyl group, is less amplified to fit the page.

CHI crotonic acid

,. (a)

Draw asplitting diagram and analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement. Justify the use of first-order analysis.

(b)

There are certain conventions used for naming spin-systems (e.g. AMX, AMX2, AM 2X3) . Note that this is a 5-spin system and name the spin system responsible for this spectrum (see Section 5.6).

/ i

!

CH 3 group i i i

730

720

710

I

i

700

690

i

600

I

I

590

580

(Hz from TMS)

438

j

570

, ---0,----.,--....,...-200

190

180

Chapter 9.4 NMR Spectral Analysis

Problem 328 The 100 MHz IH NMR spectrum (5% in CDCl 3 ) of an a,p-unsaturated aldehyde C4H60 is given below. (a)

Draw a splitting diagram and analyse this spectrum by first-order methods, i.e. extract all relevant coupling constants (J in Hz) and chemical shifts (8 in ppm) by direct measurement.

(b)

Justify the use of a first-order analysis (see Section 5.6).

(c)

Use the coupling constants to obtain the structure of the compound, inclu~ing the stereochemistry about the double bond (see Section 5.7).

1H

'IH

I

I

i

960

950

700

,.

'IH 680

630

610

210

190

(Hz from TMS)

439

Chapter 9.4 NMR Spectral Analysis

Problem 329 Draw a schematic (line) representation of the pure first-order spectrum (AMX3) corresponding to the following parameters:

= 80; vM = 220; Yx = 320. JAM = 10; JAX = 12; J MX = O.

Frequencies (Hz from TMS):

VA

Coupling constants (Hz):

Assume that the spectrum is a pure first-order spectrum and ignore small distortions in relative intensities oflines that would be apparent in a "real" spectrum.

i

(a)

Sketch in "splitting diagrams" above the schematic spectrum to indicate which sp1ittings correspond to which coupling constants.

(b)

Give the chemical shifts on the 8 scale corresponding to the above spectrum obtained with an instrument operating at 60 MHz for protons.

/

I

I

350

440

300

250

I

I

I

I

200

150

I

100

(Hz from TMS)

r,

Chapter 9.4 NMR Spectral Analysis

Problem 330 A portion of the 90 MHz IH NMR spectrum (5% in CDCl 3) of one of the six possible isomeric dibromoanilines is given below. Only the resonances of the aromatic protons are shown. NHz

):Br

U

):Br

hBr

y

Br

Br

AJ

Br~Br

lJ

Br

, 1

2

;;' n

NHz

yBr Br

3

4

5

Br

,.

Br

\I

6

Determine which is the correct structure for this compound using arguments based on symmetry and the magnitudes of spin-spin coupling constants (see Section 5.7).

/

2H 7.4

1H 6.4

ppm from TMS

441

Chapter 9.4 NMR Spectral Analysis

Problem 331 The 400 MHz 1H NMR spectrum (5% in CDCl3 after DzO exchange) of one of the six possible isomeric hydroxycinnamic acids is given below. OH

~COOH ~

I

1

OH

en

OH

OH

Y" I

~

~3

2

~

~

COOH

HO~5 Y"I

Cu°OH ~ I ~ 4

~

~

I

~

COOH

HO~OOH

COOH

~

I

~

6

,

Determine which is the correct structure for this compound using arguments based on symmetry and the magnitudes of spin-spin coupling constants (see Section 5.7).

J

!

1H 1H

1H

1H 1H

1H

8.0

442

7.0

ppm from TMS

\I

,.

Chapter 9.4

NMR Spectral Analysis

~"

Problem 332 H

CI

CI

H

I

:0:

In a published paper, the 90 MHz IH NMR spectrum given below was assigned to 1,5-dichloronaphthalene, C lOH6Cl2 ·

1,5-dichloronaphthalene

(a)

Why can't this spectrum belong to 1,5-dichloronaphthalene?

(b)

Suggest two alternative dichloronaphthalenes that would have structures consistent with the spectrum given.

CHCI 3

t J \.,.J \..

7.4

1 7.2

\.0,.,, _ _

7.0

V \....I V

6.8

ppm from TMS

AA1

\

Appendix

WORKED EXAMPLES This section works through two problems from the text to indicate a reasonable process for obtaining the structure of the unknown compound from the spectra provided. It should be emphasised that the logic used here is by no means the only way to arrive at the correct solution but it does provide a systematic approach to obtaining structures by assembling structural fragments identified by each type of spectroscopy.

A1

PROBLEM 91

(1)

Perform all Routine Operations (a)

From the molecular ion, the molecular weight is 198/200. The molecular ion has two peaks of equal intensity separated by two mass units. This is the characteristic pattern for a compound containing one bromine atom.

(b)

The molecular formula is C 9H 1,Br so one ean determine the degree of unsaturation (see Section 1.3). Replace the Br by H to give an effective molecular formula of C9H [2 (CnH m) whieh gives the degree of unsaturation as (n - ml2 + I) = 9 - 6 + I = 4. The compound must contain the equivalent or 4 TC bonds and/or rings. This degree of unsaturation would be consistent with one aromatic ring (with no other elements of unsaturation).

(c)

The total integral across all peaks in the 'H spectrum is 43 mill. From the molecular formula, there are II protons in the structure so this corresponds to 3.9 mill per proton. The relative numbers of protons in different environments:

8'H

Integral (mm)

(ppm) ~ ~

~ ~

7.2 3.3 2.8 2.2

19 8 8 8

Relative No. of hydrogens (rounded) 4.9 2 2 2

(5H) (2H) (2H) (2H)

Note that this analysis gives a total of 5+2+2+2 = 11 protons which is consistent with the molecular formula provided.

444

Appendix 1 Worked Examples

(d)

From the l3C spectrum there are 7 carbon environments: 4 carbons are in the typical aromatic/olefinic chemical shift range and 3 carbons in the aliphatic chemical shift range. The molecular formula is C 9H lIBr so there must be an element (or elements) of symmetry to account for the 2 carbons not apparent in the l3C spectrum.

(e)

From the l3C DEPT spectrum there are 3 CH resonances in the aromatic/olefinic chemical shift range and 3 CH2 carbons in the aliphatic chemical shift range

(f)

Calculate the extinction coefficient from the UV spectrum: £255

(2)

=

199 x 0.95 __ 357 O.53x1.0

Identify any Structural Elements (a)

There is no useful additional information from infrared spectrum.

(b)

In the mass spectrum there is a strong fragment at m/e = 91 and this indicates a possible Ph-CH2- group.

(c)

The ultraviolet spectrum shows a typical benzenoid absorption without further conjugation or auxochromes. This would also be consistent with the Ph-CH 2- group. From the l3C NMR spectrum, there is one resonance in the 13C{IH} spectrum which does not appear in the l3C DEPT spectrum. This indicates one quaternary (non-protonated) carbon. There are 4 resonances in the aromatic region, 3 x CH and 1 x quaternary carbon, which is typical of a monosubstituted benzene ring.

(d)

(e)

From the IH NMR, there arc 5 protons near <5 ~ 7.2 which strongly suggests a monosubstituted benzene ring, consistent with (b), (c) and (d). The Ph-CH2- group is confirmed. The triplet at approximately <5 3.3 ppm of intensity 2H suggests a CH 2 group. The downfield chemical shift suggests a -CH 2-X group with X being an electron withdrawing group (probably bromine). The triplet splitting indicates that there must be another CH 2 as a neighbouring group. In the expanded proton spectrum 1 ppm = 42 mm and since this is a 200 MHz NMR spectrum, therefore 200 Hz = 42 mm. The.triplet spacing is measured to be 1.5 mm i.e. ].1 Hz and this is typical of vicinal coupling (3JHH ) · The triplet at approximately 8 2.8 ppm of intensity 2H in the IH NMR spectrum suggests a CH 2 with one CH 2 as a neighbour. The spacing of this triplet is almost identical with that observed for the triplet near 83.3 ppm. The quintet at approximately 8 2.2 ppm. of intensity 2H has the same spacings as observed in the triplets near <52.8 and 8 3.3 ppm. This signal is consistent with a CH 2 group coupled to two flanking CH 2 groups. A sequence -CH 2-CH2-CH2- emerges in agreement with the l3C data.

Appendix 1 Worked Examples

"

Thus the structural elements are:

(3)

1.

Ph-CH 2 -

2.

-CH 2-CH 2-CH 2 -

3.

-Br

Assemble the Structural Elements

Clearly there must be some common segments in these structural elements since the total number of C and H atoms adds to more than is indicated in the molecular formula. One of the CH z groups in structural element (2) must be the benzylic CH z group of structural element (1). The structural elements can be assembled in only one way and this identifies the compound as l-bromo3-phenylpropane.

(4)

Check that the answer is consistent with all spectra.

There are no additional strong fragments in the mass spectrum. In the infrared spectrum there are two strong absorptions between 600 and 800 cm! which are consistent with the C-Br stretch of alkyl bromide.

446

Appendix 1 Worked Examples

A2

PROBLEM 121

(1)

Perform all Routine operations (a)

The molecular formula is given as C 9H 11N02. The molecular ion in the mass spectrum gives the molecular weight as 165.

(b)

From the molecular formula, C 9H llN02 , determine the degree of unsaturation (see Section 1.3). Ignore the atoms and ignore the Nand remove one H to give an effective molecular formula ofCgH 10 (CnH m ) which gives the degree of unsaturation as (n - ml2 + 1) = 9 - 5 + 1 = 5. The compound must contain the equivalent or 5 n bonds and/or rings. This degree of un saturation would be consistent with one aromatic ring with one other ring or double bond.

(c)

The total integral across all peaks in the IH spectrum is 54 mm. From the molecular formula, there are 11 protons in the structure so this corresponds to 4.9 mID per proton. The relative numbers of protons in different environments:

°

8 tH (ppm) ~ ~ ~ ~

Integral (mm)

7.9 6.6 4.3 4.0

Relative No. of hydrogens (rounded) 1.8 2 2 2 3

9 10 10 10 15

~1.4

(2H) (2H) (2H) (2H) (3H)

Note that this analysis gives a total of 2+2+2+2 + 3 = 11 protons which is consistent with the molecular formula provided. (d)

From the I3C spectrum there are 7 carbon environments: 4 carbons are in the typical aromatic/olefinic chemical shift range, 2 carbons in the aliphatic chemical shift range and 1 carbon at low field (167 ppm) characteristic of a carbonyl carbon. The molecular formula is given as C 9H 11N02 so there must be an element (or elements) of symmetry to account for the 2 carbons not apparent in the I3C spectrum.

(e)

From the 13C off-resonance decoupled spectrum there are 2 CH resonances in the aromatic/olefinic chemical shift range, one CH 2 and one CH 3 carbon in the aliphatic chemical shift-range.

(f)

Calculate the extinction coefficient from the UV spectrum:

=

£ 292

165xO.90 0.0172 x 0.5

=

17,267

Appendix 1 Worked Examples

(2)

Identify any Structural Elements (a)

From the infrared spectrum, there is a strong absorption at 1680 cm' and this is probably a C=O stretch at an unusually low frequency (such as an amide or strongly conjugated ketone).

(b)

In the mass spectrum there are no obvious fragment peaks, but the difference between 165 (M) and 137 = 28 suggests loss of ethylene (CH 2=CH2) or CO.

(c)

In the UV spectrum, the presence of extensive conjugation is apparent from the large extinction coefficient (£::::; 17,000).

(d)

In the I H NMR spectrum: The appearance of a 4 proton symmetrical pattern in the aromatic region near 8 7.9 and 6.6 ppm is strongly indicative of a para disubstituted benzene ring. This is confirmed by the presence of two quaternary 13C resonances at 8 152 and 119 ppm in the I3C spectrum and two CH I3C resonances at 8 131 and 113 ppm. Note that the presence of a para disubstituted benzene ring also accounts for the element of symmetry identified above. The triplet of 3H intensity at approximately (5 - 1.4 and the quartet of 2H intensity at approximately 8 ~ 4.3 have the same spacings of 1.1 nun. On this 100 MHz NMR spectrum, 100 Hz (1 ppm) corresponds to 16.5 mm so the measured splitting of 1.1 mm corresponds to a coupling of6.7 Hz that is typical ofa vicinal coupling constant. The triplet and quartet clearly correspond to an ethyl group and the downfield shift of the CH 2 resonance (8 ~ 4.3) indicates that it must be attached to a heteroatom so this is possibly an -O-CH 2-CH 3 group.

(e)

In the I3C NMR spectrum: The signals at 8 ] 4 (CHi) and 8 60 (CH 2) in the I3C NMR spectrum confirm the presence of the ethoxy group and the 4 resonances in the aromatic region (2 x CH and 2 x quaternary carbons) confirm the presence of a p-disubstituted benzene ring. The quaternary carbon signal at 8 167 ppm in the I3C NMR spectrum indicates an ester or an amide carbonyl group. The following structural elements have been identified so far:

ethoxy group carbonyl group In total this accounts for C 9H9 0 2 and this differs from the given molecular formula only by NH 2 . The presence of an -NH 2 group is confirmed by the exchangeable signal at 8 - 4.0 in the II-! NMR spectrum and the

448

Appendix 1 Worked Examples

characteristic N-H stretching vibrations at 3200 - 3350 crn' in the lR spectrum.

(f)

(3)

The presence of one aromatic ring plus the double bond in the carbonyl group is consistent with the calculated degree of unsaturation - there can be no other rings or multiple bonds in the structure.

Assemble the Structural Elements

The structural elements:

-,

/

C=O

can be assembled as either as:

H2N-<J--~-OCH2CH3

.or

o

(A)

(B)

These possibilities can be distinguished because: (a)

The amine -NH 2 group in (A) is "exchangeable with D20" as stated in the data but the amide -NH 2 group in (B) would require heating or base catalysis.

(b)

From Table 5.4, the IH chemical shift of the -O-CH 2- group fits better to the ester structure in (A) than the phenoxy ether structure in (B) given the models:

1.38 4.37 CH3-CH2-0-C-C6Hs II

o 1.38

3.98

CH3-CH2-0-C6Hs

(c)

The 13C chemical shifts of the quaternary carbons in the aromatic ring aromatic ring are at approximately 152 and 119 ppm. From Table 6.7, these shifts would be consistent with a -NH2 and an ester substituent on an aromatic ring (structure A) but for an -OEt substituent (as in structure B), the ipso carbon would be expected at much lower field (between 160 and 170 ppm). The 13C chemical shifts are consistent with structure (A).

449

Appendix 1 Worked Examples

(d)

The fragmentation pattern in the mass spectrum shown below fits (A) but not (B). The key fragments at m/e 137, 120 and 92 can be rationalised only from (A). This is decisive and ethyl4-aminobenzoate (A) must be the correct answer.

+.

0

/CH 2, H

o

II

CH 2

~6

~C/

¢

- OCH 2CH3

•

Q NH2

+

-CO

•

Q NH2

NH2

m/z

450

= 165

m/z = 120

m/z> 92

Subject Index

Subject Index Key:

13C NMR = Carbon 13 nuclear magnetic resonance spectrometry H NMR = Proton nuclear magnetic resonance spectrometry 2D NMR = 2-dimensional NMR IR = Infrared spectroscopy MS = Mass spectrometry UV = Ultraviolet spectroscopy I

Absorbance, molar

8,9

Anion Radical, MS . Anisotropy, magnetic, NMR

Aldehydes DC NMR

71

Appearance potential, MS

I

43,44

Aromatic compounds

H NMR

IR

18

Alkanes

21 47,48 21

13C NMR

71, 74

I

44,46,47

H NMR

DCNMR

71,72

polynuclear

46, 74

lHNMR

44,61

UV

13

Alkenes

Aromatic Solvent Induced Shift

84

13CNMR

71,72

(ASIS)

I

44,45,62

Auxochrome,

10, 13

IR

19,20

Base peak, MS

24

UV

11

Bathochromic shift, UV

10

Beer-Lambert Law

2, 8

H NMR

Alkynes 13CNMR

71,73

Boltzmann excess, NMR

35

IHNMR

44

Cation radical, MS

21,22

IR

19,20

Carbonyl compounds

Allenes

13CNMR

71-74

DCNMR

70

IR

18

IR

20

MS

31,32

UV

12

Amides DCNMR

71

IHNMR

44,49,77

DC NMR

71

IR

18

IHNMR

44,49

IR

18

MS

32

Amines I

H NMR

IR Analysis of lH NMR Spectra

44,49,77 19

Carboxylic acids

Chemical Ionisation, MS

22

53-60

451

Subject Index

Chemical shift aromatic solvent induced

40

Esters,

84

(ASIS)

71

IR

18

MS

31,32

IJC, tables

70-74

factors influencing

42,47-48

Exchange broadening, NMR

75

IH,

43-46

Exchangeable protons, NMR

44,49,77

scale

40-41

19

34, 84

standard

41

First-order spectra, NMR

54

tables

Chirality, effect on NMR

77-78

Chromophore

3

Cleavage, MS

452

IJC NMR

(J.-

31

13-

30

F NMR

rules for analysis

53,55-56

Fourier transformation, NMR

39

Fourier Transform Infrared, FTIR

16

Fragmentation, MS

21,26-32

common fragments

27

Conformational exchange

76

Free induction decay (FID), NMR

39

Connectivity

4

Halogen derivatives, IR

\9

Contour plot, 2D NMR

80

Halogen derivatives, isotopes, MS

25-26

Correlation Spectroscopy (COSY)

80,81

Heteroaromatic compounds

2DNMR

13C NMR

74

Coupling constant

IHNMR

46 80, 82

NMR

50

Heteronuclear Shi ft Correlation

allylic

62

(HSC), 2D NMR

aromatic systems

61-63

High-resolution mass spectroscopy

24

geminal

61

Hydrogen bonding, IR

17

heteroaromatic systems

63

Hydroxyl groups

olefinic

62

IR

17

vicinal

61

IHNMR

44,49,77

Cyanates, IR

20

Hypsochromic shift, UV

10

Degree of Unsaturation

3,4

Imines, IR

19

Deshielding, NMR

42,47,48

Intermolecular exchange

77

Dienes, UV

11

Ionisation, MS

D 20 exchange

49

chemical ionisation (CI)

22

DEPT, IJC NMR

67,68

electron impact, (El)

21-23

Electrospray Ionisation, MS

22

electrospray

22

Enol ethers, IR

19

matrix assisted (MALDI)

22

Equivalence, NMR

42,54

Isotope ratio, MS

25-26

accidental

42

Isocyanates, IR

20

chemical

42,54

Karplus relationship, NMR

61

magnetic

54

Subject Index

Ketones

Ring current effect, NMR

47

13C NMR

71

Saturation, NMR

36

[R

18

Sensitivity

5

MS

31, 32

Shielding, NMR

42,47,48

44,49,77

Spectrometry, Mass

21

Labile protons Lactones

Spectroscopy, definition of

IR

18

[R

Larmor equation

34

NMR

M + I, M+2 peaks, MS

25

13C

Magnetic anisotropy

47,48

continuous wave (C\V)

37

Mc Lafferty rearrangement

32

Fourier transform (FT)

39

MALDI, MS

22

UV

7

Mass number, MS

24

pH dependence

13-14

Mass spectrometry

21

solventdependencc

14

Matrix Assisted Laser Desorption

22

Ionisation, MS

15 NMR

33

65

Spin, nuclear, NMR

33

Spin decoupling, NMR

60

Metastable peaks, MS

28

broad band

65

Molecular ion, MS

21

noise

65

Nitrogen Rule, MS

24

off resonance (SFORD)

66

selective

60

Nitrilcs

13C NMR

71,72,74

Spin quantum number, NMR

33,34

IHNMR

44,45,46

Spin-spin coupling

50

IR

20

strongly coupled systems

53, 54

Nitro compounds, IR

19

weakly coupled systems

53,54

NMR spectroscopy

33, 65

NMR time-scale

75, 76

Nuclear Overhauser effect (NOE)

79

NMR

Spin system, NMR naming conventions

53 54

Splitting diagram, NMR

57

Structural clement

3

NOESY, 2D NMR

80,81-82

Sulfonamides, lR

[9

31 p NMR

34,84

Sulfonate esters, IR

19

Partial double bonds

77

Sulfones, IR

19

Sulfoxides, IR

19

Polynuclear aromatic compounds 1JC NMR

74

Time of Flight (TOF), MS

24

I

46

Two-dimensional NMR

80

Prochiral centre

76-77

T J , NMR

36

Relaxation, NMR

36

Thiocyanates, IR

20

spin lattice

36

Thiols, IH NMR

44,49,77

Residual solvent peaks

49

TOCSY, 2D NMR

80,83

Resonance, NMR

34

Wavenumber, IR

15

H NM R

453