Spectrometric Identification of Organic Compounds

ISBN-13: 9780470616376 / Angielski / Miękka / 2014 / 464 str.

Robert M. Silverstein; Francis X. Webster; David Kiemle

Opis

First published over 40 years ago, this was the first text on the identification of organic compounds using spectroscopy. This text is now considered to be a classic. This text presents a unified approach to the structure determination of organic compounds based largely on mass spectrometry, infrared (IR) spectroscopy, and multinuclear and multidimensional nuclear magnetic resonance (NMR) spectroscopy. The key strength of this text is the extensive set of practice and real-data problems (in Chapters 7 and 8). Even professional chemists use these spectra as reference data. Spectrometric Identification of Organic Compounds is written by and for organic chemists, and emphasizes the synergistic effect resulting from the interplay of the spectra. This book is characterized by its problem-solving approach with extensive reference charts and tables. The 8th edition of this text maintains its student-friendly writing style - wording throughout has been updated for consistency and to be more reflective of modern usage and methods. Chapter 3 on proton NMR spectroscopy has been overhauled and updated. Also, new information on polymers and phosphorus functional groups has been added to Chapter 2 on IR spectroscopy.

Spis treści

CHAPTER 1 MASS SPECTROMETRY 1

1.1 Introduction 1

1.2 Instrumentation 2

1.3 Ionization Methods 3

1.3.1 Gas–Phase Ionization Methods 3

1.3.1.1 Electron Impact Ionization 3

1.3.1.2 Chemical Ionization 3

1.3.2 Desorption Ionization Methods 4

1.3.2.1 Field Desorption Ionization 4

1.3.2.2 Fast Atom Bombardment Ionization 4

1.3.2.3 Plasma Desorption Ionization 5

1.3.2.4 Laser Desorption Ionization 6

1.3.3 Evaporative Ionization Methods 6

1.3.3.1 Thermospray Mass Spectrometry 6

1.3.3.2 Electrospray Mass Spectrometry 6

1.4 Mass Analyzers 8

1.4.1 Magnetic Sector Mass Spectrometers 8

1.4.2 Quadrupole Mass Spectrometers 9

1.4.3 Ion Trap Mass Spectrometer 10

1.4.4 Time–of–Flight Mass Spectrometer 11

1.4.5 Fourier Transform Mass Spectrometer 12

1.4.6 Tandem Mass Spectrometry 12

1.5 Interpretation of EI Mass Spectra 12

1.5.1 Recognition of the Molecular Ion Peak 13

1.5.2 Determination of a Molecular Formula 14

1.5.2.1 Unit–Mass Molecular Ion and Isotope Peaks 14

1.5.2.2 High–Resolution Molecular Ion 15

1.5.3 Use of the Molecular Formula. Index of Hydrogen Deficiency 15

1.5.4 Fragmentation 16

1.5.5 Rearrangements 18

1.6 Mass Spectra of Some Chemical Classes 18

1.6.1 Hydrocarbons 18

1.6.1.1 Saturated Hydrocarbons 18

1.6.1.2 Alkenes (Olefins) 19

1.6.1.3 Aromatic and Aralkyl Hydrocarbons 21

1.6.2 Hydroxy Compounds 22

1.6.2.1 Alcohols 22

1.6.2.2 Phenols 23

1.6.3 Ethers 24

1.6.3.1 Aliphatic Ethers (and Acetals) 24

1.6.3.2 Aromatic Ethers 25

1.6.4 Ketones 26

1.6.4.1 Aliphatic Ketones 26

1.6.4.2 Cyclic Ketones 26

1.6.4.3 Aromatic Ketones 26

1.6.5 Aldehydes 28

1.6.5.1 Aliphatic Aldehydes 28

1.6.5.2 Aromatic Aldehydes 28

1.6.6 Carboxylic Acids 28

1.6.6.1 Aliphatic Acids 28

1.6.6.2 Aromatic Acids 29

1.6.7 Carboxylic Esters 29

1.6.7.1 Aliphatic Esters 29

1.6.7.2 Benzyl and Phenyl Esters 30

1.6.7.3 Esters of Aromatic Acids 30

1.6.8 Lactones 31

1.6.9 Amines 31

1.6.9.1 Aliphatic Amines 31

1.6.9.2 Cyclic Amines 32

1.6.9.3 Aromatic Amines (Anilines) 32

1.6.10 Amides 32

1.6.10.1 Aliphatic Amides 32

1.6.10.2 Aromatic Amides 32

1.6.11 Aliphatic Nitriles 32

1.6.12 Nitro Compounds 33

1.6.12.1 Aliphatic Nitro Compounds 33

1.6.12.2 Aromatic Nitro Compounds 33

1.6.13 Aliphatic Nitrites 33

1.6.14 Aliphatic Nitrates 33

1.6.15 Sulfur Compounds 33

1.6.15.1 Aliphatic Mercaptans (Thiols) 33

1.6.15.2 Aliphatic Sulfides 34

1.6.15.3 Aliphatic Disulfides 34

1.6.16 Halogen Compounds 35

1.6.16.1 Aliphatic Chlorides 35

1.6.16.2 Aliphatic Bromides 35

1.6.16.3 Aliphatic Iodides 35

1.6.16.4 Aliphatic Fluorides 36

1.6.16.5 Benzyl Halides 37

1.6.16.6 Aromatic Halides 37

1.6.17 Heteroaromatic Compounds 37

References 37

Student Exercises 37

Appendices 46

A Formula Masses (FM) for Various Combinations of Carbon, Hydrogen, Nitrogen, and Oxygen 46

B Common Fragment Ions 67

C Common Fragments Lost 69

CHAPTER 2 INFRARED SPECTROSCOPY 71

2.1 Introduction 71

2.2 Theory 71

2.2.1 Coupled Interactions 74

2.2.2 Hydrogen Bonding 75

2.3 Instrumentation 76

2.3.1 Dispersion IR 76

2.3.2 Fourier Transform Infrared Spectrometer (Interferometer) 76

2.4 Sample Handling 77

2.5 Interpretation of Spectra 78

2.6 Characteristic Group Absorptions of Organic Molecules 81

2.6.1 Normal Alkanes (Paraffins) 81

2.6.1.1 C H Stretching Vibrations 81

2.6.1.2 C H Bending Vibrations 81

2.6.2 Branched–Chain Alkanes 82

2.6.2.1 C H Stretching Vibrations: Tertiary C H Groups 82

2.6.2.2 C H Bending Vibrations: gem–Dimethyl Groups 82

2.6.3 Cyclic Alkanes 83

2.6.3.1 C H Stretching Vibrations 83

2.6.3.2 C H Bending Vibrations 83

2.6.4 Alkenes 83

2.6.4.1 C C Stretching Vibrations Unconjugated Linear Alkenes 83

2.6.4.2 Alkene C H Stretching Vibrations 84

2.6.4.3 Alkene C H Bending Vibrations 84

2.6.5 Alkynes 84

2.6.5.1 C C Stretching Vibrations 84

2.6.5.2 C H Stretching Vibrations 85

2.6.5.3 C H Bending Vibrations 85

2.6.6 Mononuclear Aromatic Hydrocarbons 85

2.6.6.1 Out–of–Plane C H Bending Vibrations 85

2.6.7 Polynuclear Aromatic Hydrocarbons 86

2.6.8 Polymers 86

2.6.9 Alcohols and Phenols 88

2.6.9.1 O H Stretching Vibrations 88

2.6.9.2 C O Stretching Vibrations 89

2.6.9.3 O H Bending Vibrations 89

2.6.10 Ethers, Epoxides, and Peroxides 89

2.6.10.1 C O Stretching Vibrations 89

2.6.11 Ketones 92

2.6.11.1 C O Stretching Vibrations 92

2.6.11.2 C C( O) C Stretching and Bending Vibrations 94

2.6.12 Aldehydes 94

2.6.12.1 C O Stretching Vibrations 94

2.6.12.2 C H Stretching Vibrations 94

2.6.13 Carboxylic Acids 94

2.6.13.1 O H Stretching Vibrations 94

2.6.13.2 C O Stretching Vibrations 95

2.6.13.3 C O Stretching and O H Bending Vibrations 95

2.6.14 Carboxylate Anion 95

2.6.15 Esters and Lactones 96

2.6.15.1 C O Stretching Vibrations 96

2.6.15.2 C O Stretching Vibrations 97

2.6.16 Acid Halides 97

2.6.16.1 C O Stretching Vibrations 97

2.6.17 Carboxylic Acid Anhydrides 97

2.6.17.1 C O Stretching Vibrations 97

2.6.17.2 C O Stretching Vibrations 97

2.6.18 Amides and Lactams 98

2.6.18.1 N H Stretching Vibrations 98

2.6.18.2 C O Stretching Vibrations (Amide I Band) 99

2.6.18.3 N H Bending Vibrations (Amide II Band) 99

2.6.18.4 Other Vibration Bands 99

2.6.18.5 C O Stretching Vibrations of Lactams 100

2.6.19 Amines 100

2.6.19.1 N H Stretching Vibrations 100

2.6.19.2 N H Bending Vibrations 100

2.6.19.3 C N Stretching Vibrations 100

2.6.20 Amine Salts 100

2.6.20.1 N H Stretching Vibrations 100

2.6.20.2 N H Bending Vibrations 101

2.6.21 Amino Acids and Salts of Amino Acids 101

2.6.22 Nitriles 101

2.6.23 Isonitriles (R N C), Cyanates (R O C N), Isocyanates (R N C O), Thiocyanates (R S C N), and Isothiocyanates (R N C S) 102

2.6.24 Compounds Containing a N N Group 102

2.6.25 Covalent Compounds Containing Nitrogen Oxygen Bonds 102

2.6.25.1 N O Stretching Vibrations 102

2.6.26 Organic Sulfur Compounds 103

2.6.26.1 S H Stretching Vibrations: Mercaptans 103

2.6.26.2 C S and C S Stretching Vibrations 103

2.6.27 Compounds Containing Sulfur Oxygen Bonds 104

2.6.27.1 S O Stretching Vibrations 104

2.6.28 Organic Halogen Compounds 105

2.6.29 Silicon Compounds 106

2.6.29.1 Si H Vibrations 106

2.6.29.2 SiO H and Si O Vibrations 106

2.6.29.3 Silicon–Halogen Stretching Vibrations 106

2.6.30 Phosphorus Compounds 106

2.6.30.1 P H, P C, P O, and P O Stretching Vibrations 106

2.6.31 Heteroaromatic Compounds 107

2.6.31.1 C H Stretching Vibrations 107

2.6.31.2 N H Stretching Frequencies 107

2.6.31.3 Ring Stretching Vibrations (Skeletal Bands) 108

2.6.31.4 C H Out–of–Plane Bending 108

References 108

Student Exercises 108

Appendices 118

A Transparent Regions of Solvents and Mulling Oils 118

B Characteristic Group Absorptions 119

C Absorptions for Alkenes 124

D Absorptions for Phosphorus Compounds 125

E Absorptions for Heteroaromatics 125

CHAPTER 3 PROTON (1H) MAGNETIC RESONANCE SPECTROSCOPY 126

3.1 Introduction 126

3.2 Theory 126

3.2.1 Magnetic Properties of Nuclei 126

3.2.2 Excitation of Spin 1 2 Nuclei 127

3.2.3 Relaxation 128

3.3 Instrumentation and Sample Handling 129

3.3.1 Instrumentation 129

3.3.2 Sensitivity of NMR Experiments 130

3.3.3 Solvent Selection and Sample Handling 131

3.4 Chemical Shift 132

3.5 Spin–Spin Coupling, Multiplets, and Spin Systems 137

3.5.1 Simple and Complex First–Order Multiplets 137

3.5.2 First–Order Spin Systems 140

3.5.3 Pople Notation 140

3.5.4 Further Examples of Simple First–Order Spin Systems 141

3.5.5 Analysis of First–Order Multiplets 143

3.6 Protons on Oxygen, Nitrogen, and Sulfur Atoms: Exchangeable Protons 144

3.6.1 Protons on an Oxygen Atom 144

3.6.1.1 Alcohols 144

3.6.1.2 Water 146

3.6.1.3 Phenols 147

3.6.1.4 Enols 147

3.6.1.5 Carboxylic Acids 147

3.6.2 Protons on Nitrogen 147

3.6.3 Protons on Sulfur 149

3.6.4 Protons on or near Chlorine, Bromine, or Iodine Nuclei 149

3.7 Coupling of Protons to Other Important Nuclei (19F, D (2H), 31P, 29Si, and 13C) 149

3.7.1 Coupling of Protons to 19F 149

3.7.2 Coupling of Protons to D (2H) 149

3.7.3 Coupling of Protons to 31P 150

3.7.4 Coupling of Protons to 29Si 150

3.7.5 Coupling of Protons to 13C 150

3.8 Chemical Equivalence 150

3.8.1 Determination of Chemical Equivalence by Interchange Through Symmetry Operations 150

3.8.2 Determination of Chemical Equivalence by Tagging (or Substitution) 151

3.8.3 Chemical Equivalence by Rapid Interconversion of Structures 151

3.8.3.1 Keto–Enol Interconversion 151

3.8.3.2 Interconversion Around a Partial Double Bond (Restricted Rotation) 152

3.8.3.3 Interconversion Around the Single Bonds of Rings 152

3.8.3.4 Interconversion Around the Single Bonds of Chains 152

3.9 Magnetic Equivalence 154

3.10 AMX, ABX, and ABC Rigid Systems with Three Coupling Constants 155

3.11 Weakly and Strongly Coupled Systems: Virtual Coupling 156

3.11.1 Weakly Coupled Systems 156

3.11.1.1 1–Nitropropane 156

3.11.2 Strongly Coupled Systems 157

3.11.2.1 1–Hexanol 157

3.11.2.2 3–Methylglutaric Acid 157

3.12 Chirality 158

3.13 Magnitude of Vicinal and Geminal Coupling Constants 160

3.14 Long–Range Coupling 162

3.15 Selective Spin Decoupling: Double Resonance 162

3.16 Nuclear Overhauser Effect 162

3.17 Conclusion 163

References 164

Student Exercises 164

Appendices 175

A Chart A.1: Chemical Shifts of Protons on a Carbon Atom Adjacent ( Position) to a Functional Group in Aliphatic Compounds (M Y) 175

Chart A.2: Chemical Shifts of Protons on a Carbon Atom Once Removed ( Position) from a Functional Group in Aliphatic Compounds (M C Y) 177

B Effect on Chemical Shifts by Two or Three Directly Attached Functional Groups 178

C Chemical Shifts in Alicyclic and Heterocyclic Rings 180

D Chemical Shifts in Unsaturated and Aromatic Systems 181

Chart D.1: Chemical Shifts of Protons on Monosubstituted Benzene Rings 183

E Protons Subject to Hydrogen–Bonding Effects (Protons on Heteroatoms) 184

F Proton Spin–Spin Coupling Constants 185

G Chemical Shifts and Multiplicities of Residual Protons in Commercially Available Deuterated Solvents 187

H Chemical Shifts of Common Laboratory Solvents as Trace Impurities 188

I Proton NMR Chemical Shifts of Amino Acids in D2O 190

CHAPTER 4 CARBON–13 NMR SPECTROSCOPY 191

4.1 Introduction 191

4.2 Theory 191

4.2.1 1H Decoupling Techniques 191

4.2.2 Chemical Shift Scale and Range 192

4.2.3 T1 Relaxation 193

4.2.4 Nuclear Overhauser Effect (NOE) 193

4.2.5 13C 1H Spin–Spin Coupling (J Coupling) 196

4.2.6 Sensitivity 197

4.2.7 Solvents 197

4.3 Interpretation of a Simple 13C NMR Spectrum: Diethyl Phthalate 198

4.4 Quantitative 13C Analysis 198

4.5 Chemical Equivalence 200

4.6 DEPT 200

4.7 Chemical Classes and Chemical Shifts 203

4.7.1 Alkanes 204

4.7.1.1 Linear and Branched Alkanes 204

4.7.1.2 Effect of Substituents on Alkanes 205

4.7.1.3 Cycloalkanes and Saturated Heterocyclics 205

4.7.2 Alkenes 206

4.7.3 Alkynes 208

4.7.4 Aromatic Compounds 208

4.7.5 Heteroaromatic Compounds 209

4.7.6 Alcohols 209

4.7.7 Ethers, Acetals, and Epoxides 209

4.7.8 Halides 211

4.7.9 Amines 211

4.7.10 Thiols, Sulfides, and Disulfides 211

4.7.11 Functional Groups Containing Carbon 211

4.7.11.1 Ketones and Aldehydes 212

4.7.11.2 Carboxylic Acids, Esters, Chlorides, Anhydrides, Amides, and Nitriles 214

4.7.11.3 Oximes 214

References 214

Student Exercises 214

Appendices 225

A The 13C Chemical Shifts, Coupling Constants, and Peak Multiplicities of Common Deuterated NMR Solvents 225

B 13C Chemical Shifts of Common Laboratory Solvents as Trace Impurities in Selected Deuterated NMR Solvents 226

C 13C Chemical Shift Ranges for Chemical Classes 227

D 13C Chemical Shifts (ppm) for Several Natural Products 229

CHAPTER 5 TWO–DIMENSIONAL NMR SPECTROSCOPY 230

5.1 Introduction 230

5.2 Theory 231

5.3 Correlation Spectroscopy 233

5.3.1 1H 1H Correlation: COSY 235

5.4 Ipsenol: 1H 1H COSY 235

5.4.1 Ipsenol: Double Quantum Filtered 1H 1H COSY 238

5.4.2 Carbon Detected 13C 1H COSY: HETCOR 238

5.4.3 Proton Detected 1H 13C COSY: HMQC 239

5.4.4 Ipsenol: HETCOR and HMQC 239

5.4.5 Ipsenol: Proton–Detected, Long–Range 1H 13C Heteronuclear Correlation: HMBC 241

5.5 Caryophyllene Oxide 243

5.5.1 Caryophyllene Oxide: DQF–COSY 243

5.5.2 Caryophyllene Oxide: HMQC 243

5.5.3 Caryophyllene Oxide: HMBC 247

5.6 13C 13C Correlations: INADEQUATE 249

5.6.1 INADEQUATE: Caryophyllene Oxide 251

5.7 Lactose 251

5.7.1 DQF–COSY: Lactose 251

5.7.2 HMQC: Lactose 254

5.7.3 HMBC: Lactose 254

5.8 Relayed Coherence Transfer: TOCSY 254

5.8.1 2D TOCSY: Lactose 254

5.8.2 1D TOCSY: Lactose 257

5.9 HMQC–TOCSY 259

5.9.1 HMQC–TOCSY: Lactose 259

5.10 ROESY 259

5.10.1 ROESY: Lactose 259

5.11 VGSE 262

5.11.1 COSY: VGSE 262

5.11.2 TOCSY: VGSE 262

5.11.3 HMQC: VGSE 262

5.11.4 HMBC: VGSE 264

5.11.5 ROESY: VGSE 265

5.12 Pulsed Field Gradient NMR 265

References 268

Student Exercises 268

CHAPTER 6 MULTINUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 298

6.1 Introduction and General Considerations 298

6.2 15N Nuclear Magnetic Resonance 299

6.3 19F Nuclear Magnetic Resonance 306

6.4 29Si Nuclear Magnetic Resonance 309

6.5 31P Nuclear Magnetic Resonance 312

6.6 Conclusions 315

References 315

Student Exercises 315

Appendix 320

A Properties of Magnetically Active Nuclei 320

CHAPTER 7 SOLVED PROBLEMS 325

7.1 Introduction 325

Problem 7.1 Discussion 329

Problem 7.2 Discussion 333

Problem 7.3 Discussion 337

Problem 7.4 Discussion 344

Problem 7.5 Discussion 350

Problem 7.6 Discussion 356

Student Exercises 357

CHAPTER 8 ASSIGNED PROBLEMS 364

8.1 Introduction 364

INDEX 453