INTRODUCTION TO INFRARED AND RAMAN SPECTROSCOPY

Transcription

1 INTRODUCTION TO INFRARED AND RAMAN SPECTROSCOPY THIRD EDITION Norman B. Colthup Lawrence H. Daly *', "!*",, Stephen E. Wiberley ACADEMIC PRESS, INC. Harcourt Brace Jovanovich, Publishers Boston San Diego New York London Sydney Tokyo Toronto

2 :: ' txi. PREFACE.' Chapter 1 VIBRATIONAL AND ROTATIONAL SPECTRA 1.1 Introduction, 1; 1.2 Photon Energy, 2; 1.3 Degrees of Freedom of Molecular Motion, 3; 1.4 Normal Modesof Vibration, 4; 1.5 Mechanical Molecular Models, 4; 1.6 Coordinates Used to Describe Molecular Vibrations, 6; 1.7 Classical Vibrational Frequency Formula for Diatomic Molecule, 7; 1.8 Infrared Absorption and the Change in Dipole Moment, 11; 1.9 Anharmonicity and Overtones, 15; 1.10 Vibrational Potential Function, 16; 1.11 Introduction to the Quantum Effect, 19; 1.12 The Quantum Mechanical Harmonie Oscillator, 23; 1.13 The Boltzmann Distribution Function, 25; 1.14 Vibrational Transitions and Infrared Absorption, 26; 1.15 The Anharmonic Oscillator, 27; 1.16 Cqmbination and Difference Bands, 30; 1.17 Fermi Resonance, 31; 1.18 Rotation of Linear Molecules, 33; 1.19 Rotational Transitions and Infrared Absorption, 37; 1.20 The Nonrigid Rotator, 41; 1.21 Rotational Line Intensities, 42; 1.22 Types of Rotators, 43; 1.23 Rotation of Symmetrie Top Molecules, 45; 1.24 Vibrational-Rotational Spectrum, Classical Picture, 46; 1.25 Vibrational-Rotational Spectrum, Quantum Mechanical Treatment, 48; 1.26 Vibrational-Rotational Spectrum, Nonrigid Rotator, 54; 1.27 Spherical Top Molecules, 56; 1.28 Symmetrical Top Molecules, 56; 1.29 Asymmetrical Top Molecules, 58; 1.30 The Raman Effect, 60; 1.31 Polarizability, 62; 1.32 The Tensor Character of the Polarizability, 65; 1.33 Depolarization Ratio, 68; 1.34 Pure Rotational Raman Spectra, 70; 1.35 Raman Sources, 72 Chapter 2 IR EXPERIMENTAL CONSIDERATIONS 2.1 Source of Infrared Radiation, 75; 2.2 Infrared Detectors, 77; 2.3 Monochromators, 77; 2.4 Interferometers, 80; 2.5 Infrared Transmitting Materials, 83; 2.6 Salt Polishing, 84; 2.7 Infrared Cells, 85; 2.8 Solid Sampling, 87; 2.9 Internal Reflection Spectroscopy, 92; 2.10 Polarized Infrared Radiation, 94; 2.11 Quantitative Analysis, 100 V

3 Chapter 3 MOLECULAR SYMMETRY 3.1 Symmetry Properties, 109; 3.2 Point Groups, 115; 3.3 Group Theory, 119; 3.4 Group Theory Applied to Point Groups, 121; 3.5 Representations of Groups, 124; 3.6 Irreducible Representations, 129; 3.7 The Character Table, 131; 3.8 Irreducible Representation Components in a Representation, 136; 3.9 Transformation Properties of a Vector, 138; 3.10 The Numberof Fundamentals ofeach Type, 139; 3.11 Selection Rules, 141; 3.12 Infrared Activity of Fundamentals, 144; 3.13 Raman Activity of Fundamentals, 145; 3.14 Overtone and Combination Bands, 146; 3.15 Symmetry Coordinates, 150; 3.16 Isotope Effects and the ProductRule, 152; 3.17 Character Tables and Selection Rules, 155 Chapter 4 THE VIBRATIONAL ORIGIN OF GROUP FREQUENCIES 4.1 Introduction, 171; 4.2 Diatomic Oscillators, 172; 4.3 Coupled Oscillators, 172; 4.4 Unsymmetrical Coupled Oscillators, 175; 4.5 X H Stretching Frequencies, 177; 4.6 Triple Bond Vibrations, 178; 4.7 Cumulated Double Bonds, 180; 4.8 The Linear M, M 2 M 3 Model, 181; 4.9 X C=N Compounds, 182; 4.10 Carbonyl and C = C Compounds, 184; 4.11 Cyclic Compound Stretching Vibrations, 188; 4.12 The Bent M, M 2 M, Stretching Frequencies, 192; 4.13 Noncyclic Single Bond Vibrations, 194; 4.14 Bend-Bend Interaction, 196; 4.15 Bend-Stretch Interaction, 202; 4.16 Multiple Oscillator Groups, 207; 4.17 Interaction Force Constant Effects, 208; 4.18 Hydrogen Bonding, 210 Chapter 5 METHYL AND METHYLENE GROUPS 5.1 Introduction to Group Frequencies, 215; 5.2 Methyl Groups, 216; 5.3 CH 3 Stretching Vibrations, 217; 5.4 CH 3 Deformation Vibrations, 222; 5.5 CH 3 Rock Vibrations, 225; 5.6 Methylene Groups, 227; 5.7 CH 2 Stretching Vibrations, 228; 5.8 CH 2 Deformation Vibrations, 228; 5.9 CH 2 Wag Vibrations, 228; 5.10 CH 2 Rock Vibrations, 230; 5.11 CH 2 Twisting Vibrations, 232; 5.12 CH 2 in Cyclic Compounds, 232; 5.13 Carbon Hydrogen Group, 233

4 Vll Chapter 6 TRIPLE BONDS AND CUMULATED DOUBLE BONDS Introduction, 235; 6.2 Monosubstituted Acetylenes, 236; 6.3 Disubstituted Acetylenes, 237; 6.4 Allenes, 238; 6.5 Nitriles, 238; 6.6 Nitrile /V-Oxides and Complexes, 239; 6.7 Cyanates, 239; 6.8 Isocyanates, 239; 6.9 Thiocyanates, 240; 6.10 Isothiocyanates, 240; 6.11 Nitriles on a Nitrogen Atom, 240; 6.12 Carbodiimides, 241; 6.13 Ketene Imines, 241; 6.14 Diazo Compounds, 241; 6.15 Azides, 243; 6.16 Aryl Diazonium Salts, 243; 6.17 Isocyanides, 244; 6.18 Ketenes, 244; 6.19 Cyanide Ions, 244; 6.20 Cyanate Ions, 245; 6.21 Thiocyanate Ions, 245; 6.22 Metal Carbonyls, 245; 6.23 Three and Four Cumulated Double Bonds, 245 Chapter 7 OLEFIN GROUPS Noncyclic Olefins, 247; 7.2 Olefinic Hydrogen Wagging Vibrations, 252; 7.3CyclicC = C, 257 Chapter 8 AROMATIC AND HETEROAROMATIC RINGS Benzene Rings, 261; 8.2 The Carbon-Carbon Vibrations, 263; 8.3 The 1600 cm 1 Region, 264; 8.4 The 1500 cm" 1 Region, 266; 8.5 The 700 cm' Region, 267; 8.6 The cm r CH Wag Bands, 268; 8.7 The cm 1 Summation Bands, 275; 8.8 The cm' Region, 276; 8.9 The cm' Region, 279; 8.10 The cm ' Region, 280; 8.11 Condensed Ring Aromatic Compounds, 281; 8.12 Pyridines, 283; 8.13 Pyridine N-Oxides, 283; 8.14 Pyrimidines, 284; 8.15 Triazines, 284; 8.16 Alkyl- or Aryl-Substituted Triazines, 284; 8.17 Melamines and Guanamines, 285; 8.18 Chloro-, Oxy-, and Thio-Substituted Triazines, 285; 8.19Tetrazines, 286; 8.20HeteroaromaticFive-Membered Ring Compounds, 286; 8.21 Cyclopentadienyl Ring-Metal Complexes, 288 Chapter 9 CARBONYL COMPOUNDS Introduction, 289; 9.2 Mass Effects, 289; 9.3 Bond Angle Effects, 292; 9.4 Inductive Effects, 293; 9.5 Mesomeric Effects, 294; 9.6Ketones, 295; 9.7 a-chloro Ketones, 295; 9.8 Conjugated Ketones, 296; 9.9 Conjugated Hydrogen Bonded Ketones, 297; 9.10 Bond Angle Effects in

5 Vlll CONTENTS Ketones, 299; 9.11 Aldehyde CH Vibrations, 300; 9.12 Aldehyde Carbonyl Vibrations, 301; 9.13 Aldehyde C C, 301; 9.14 Ester C = 0, 301; 9.15 Ester C O, 302; 9.16 Out-of-Plane Hydrogen Vibrations in Unsaturated Esters, 305; 9.17 Groups Next to the Carbonyl in Esters, 306; 9.18 Groups on the Oxygen Atoms in Esters, 307; 9.19 Lactones, 307; 9.20 Thiol Esters and Related Compounds, 308; 9.21 Organic Carbonate Derivatives and Related Compounds, 309; 9.22 Oxalates, 310; 9.23 Anhydrides, 310; 9.24 Peroxides, Acyl or Aroyl, 312; 9.25 Halogen- Substituted Carbonyls, 312; 9.26 Carboxylic Acid OH Stretch, 313; 9.27 Carboxyl-Carbonyl Stretch, 313; 9.28 Carboxyl OH Bending and C O Stretching, 315; 9.29 Monomeric Acids, 315; 9.30 Aliphatic Peroxy Acids, 316; 9.31 Aromatic Acids, 316; 9.32 Aliphatic Bands in Long Chain «-Aliphatic Carboxylic Acids, Ester, and Soaps, 317; 9.33 Carboxyl Salts, 317; 9.34 Amino Acids, 318; 9.35 Amido Acids, 319; 9.36 Unsubstituted Amides, 319; 9.37 /V-Substituted Amides (trans), 320; 9.38 /V-Substituted Amides (eis) (Lactams), 321; 9.39 Disubstituted Amides, 322; 9.40 Ureas, 322; 9.41 Carbamates, 323; 9.42 Hydroxamic Acids, 323; 9.43 Imides, 323; 9.44 Isocyanurates, 324; 9.45 Acid Hydrazides, 325 Chapter 10 ETHERS, ALCOHOLS, AND PHENOLS Aliphatic Ethers, 327; 10.2 Aromatic Ethers, 328; 10.3 Vinyl Ethers, 329; 10.4 Cyclic Ether Linkages, 331; 10.5 Oxirane Ring Compounds, 331; 10.6 OH Stretch in Alcohols and Phenols, 332; 10.7 C O Stretch, 333; 10.8 OH Deformation, 334; 10.9 Phenols, 334; Noncyclic Acetals and Related Compounds, 335; Cyclic Acetals, 335; Carbohydrates, 335; Peroxides, 336 Chapter 11 AMINES, C = N, AND N = 0 COMPOUNDS NH 2 Stretch in Amines, 339; 11.2 NH 2 Deformation in Amines, 340; 11.3 NH, 340; 11.4 C N in Aliphatic Amines, 341; 11.5 C N in Aromatic Amines, 341; 11.6 Aliphatic Bands in Amines, 342; 11.7 The Ammonium Ion, 343; 11.8 Amine Salts, 343; 11.9 C = N Groups, 344; Nitro Group, 346; Organic Nitrates, 349; Nitramines, 349; Organic Nitrates, 350; Inorganic Nitrates and Nitrites, 350; N = N Azo, 350; Azoxy and Azothio Groups, 352; C-Nitroso Compounds, 353; Nitrosamines, 354

6 IX Chapter 12 COMPOUNDS CONTAINING BORON, SILICON, PHOSPHORUS, SULFUR, OR HALOGEN Boron Compounds, 355; 12.2 B O, 355; 12.3 B OH, 356; 12.4 B-N, 356; 12.5 B H, 357; 12.6 B-Cl, 357; 12.7 B CH 358; 12.8 B Phenyl, 358; 12.9 Silicon Compounds, 358; Si H, 359; Si CH 3, 360; Si-CH 2 -R, 360; Si C 6 H 360; Si CH = CH 2, 360; Si O R, 361; Si O C H 5, 361; Si O Si, 361; Si OH, 361: Si Halogen, 362; Si N, 362; Phosphorus Compounds, 362; P H, 363; P = 0, 364; P OH, 365; P O P, 365; P0 2 -, POS", P0 3 2, P0 4 3, 366; P O C (Aliphatic), 366; P O C (Phenyl), 367; P CH 2, 367; P CH 3, 367; P Phenyl, 367; P = S, 368; P SH, 370; P N, 370; P = N, 370; P F, P Cl, P C, 371; S H, 371; Sulfides and Disulfides, 371; CH 2 S, 372; CH 3 S, 372; S-CH = CH 2, 372; S-Aryl, 373; S F, 373; SO, 373; S0 2, 373; Sulfones, 374; Sulfonamides, 375; Sulfonic Acids, 375; Sulfonic Acid Salts, 375; Sulfinic Acids, 375; HSO -, 376; S0 4 2 ", 376; SO/", 376; S O CH 2, 376; Thionylamine, 376; C = S, 377; (FHF), 379; FCH, 379; FC = C, 380; FC = 0, 380; F Aryl, 380; CF Stretch, 380; C Cl, 381; C Br, 383; C I, 385; Aryl Halides, 383; Organometallic Compounds, 384; Inorganic Metal Oxides, 385 Chapter 13 MAJOR SPECTRA-STRUCTURE CORRELATIONS BY SPECTRAL REGIONS Introduction, 387; cm" (OH, NH, and =CH), 387; cm" 1 (Aryl, Olefinic, and Three-Membered Ring CH), 388; CHT 1 (Aliphatic CH), 388; cm" (Acidic and Strongly Bonded Hydrogens), 389; cm" (SH, BH, PH, and SiH), 389; cm" (X=Y andx = Y = Z), 389; cm" (Aryl and Olefinic Overtones), 389; cm-' (C = 0), 390; cm" (C = C and C = N), 390; cm-' (N = 0), 390; cm 1 (NH 2, NH 3 +, and CNH), 391; ctir' (Aromatic and Heteroaromatic Rings), 391; cm" (CH 3 and CH 2, 391; cm" 1 (B- O, B-N, NO,, CO, 2, and NH 4, 391; cm"' (S0 2, S0 3 ", SO, and SO, 2 -), 392; cm" (P = 0), 392; cm 1 (CF 3 and CF 2, 392; cm" (CH 2 and CH Wag), 392; cm" (C O), 392; cm" (Si O and P O), 393; cm" (Olefinic and Acetylenic CH-Wag), 393; cm" (Aromatic CH Wag), 393; cm" (CC1, CBr, and Cl),

7 X CONTENTS 393; cm ' (OH, NH, and NH 2 Wag), 393; cm-' (Selected Inorganic Absorptions), 394; Mixtures, 394; Correlation Charts, 395; Selected Infrared Spectra Illustrating Functional Group Frequencies, 398; Selected Raman Spectra, 478 Chapter 14 THE THEORETICAL ANALYSIS OF MOLECULAR VIBRATIONS Normal Modes of Vibration, 483; 14.2 The Linear Triatomic Model's Stretching Frequencies, 486; 14.3 Internal Coordinates, 490; 14.4 Vibrational Solution Using Internal Coordinates, 491; 14.5 The G Matrix, 493; 14.6 The L Matrix, 497; 14.7 Normal Coordinates, 498; 14.8 Potential Energy Distribution, 500; 14.9 The Form of the Normal Coordinates, 501; Symmetry Coordinates, 502; The CHC1 3 Molecule, 505; The Internal Coordinates forchcl 3, 508; The Symmetry Coordinates forchcl,, 509; The G Matrix for CHC1 3, 518; The F Matrix for CHC1 3, 526; The Secular Determinants for CHC1 3, 528; The Frequencies of the CDC1 3 Molecules, 529; Comparison of Experimental and Calculated Wavenumbers, 530; The Form of the Chloroform Normal Coordinates, 530; The Potential Function Problem, 535; A Review of Matrix Notation, 536; The Normal Coordinate Problem in Matrix Form, 539 INDEX 543