Introductory Organic Quantum Chemistry

GEORG KARAGOUNIS
Professor of Physical of Physical Chemistry
University of Freiburg, Germany

Translated and Edited by

F. C. NACHOD
Sterling-Winthrop Research Institute Rensselaer, New York

ACADEMIC PRESS, New York and London 1962
Copyright 1962, by Academic Press Inc.
Library of Congress Catalog Card Number 62-13076

Full text

PREFACE

Organic chemists have often shied away from the quantum-mechanical approach to their discipline. This short introduction is aimed at giving a rapid and exact survey both to the young chemist in his formative years as well as to the older, established chemist who has never been exposed to quantum mechanics.

The lack of rigorous treatment will hopefully allay the inherent fears of the timid reader and overcome any trauma he may have acquired previously. At the same time it will perhaps show him the beauty and elegance of this method of looking at organic chemistry and stimulate him into the use of more advanced books on this subject.

It was a great pleasure and satisfaction to learn that an American publishing house was interested in bringing out an English translation of my German text "Einführung in die Elektronentheorie Organischer Verbindungen."

The author is much indebted to Dr. Frederick C. Nachod for his careful translation and for many valuable suggestions. The publishers have been most cooperative in the preparation of this edition for which his gratitude is recorded.

GEORG KARAGOUNIS

Freiburg im Breisgau
December, 1961

Contents
PREFACE v
1. Historical Introduction. The Quantum of Action 1
2. Some Applications of the Elementary Action Quantum. The Specific Heat 5
3. The Photoelectric Effect and the Dual Nature of Light 7
4. The Bohr Atomic Model. Its Success and Shortcomings 9
5. The Dual Nature of the Electron. The de Broglie Wave Concept of Matter 13
6. The Wave Mechanical Representation of Mechan- ical Processes. The Schroedinger Equation. Quantum Numbers 16
7. The Uncertainty Relationship of Heisenberg 24
8. The Spatial Distribution of Electronic Charge in Different Atomic States 28
9. The Covalent Bond. The H2 Molecule 33
10. The Pauli Exclusion Principle 37
11. Concepts of the Chemical Bond Prior to the Beginning of Quantum Mechanics 43
12. Mesomerism. Resonance 54
13. The Valence Bond (VB) and Molecular Orbital (MO) Methods 58
14. Resonance, Coplanarity, and Steric Hindrance 66
15. Hybridization 76
16. Bond Order and Atomic Distance 85
17. Dipole Moment and Constitution 95
18. Molar Refraction, Magnetic Susceptibility, and the Chemical Bond 109
19. The Influence of Electron Shifts on the Position of Chemical Equilibria 128
20. Color, Chemical Constitution, and Mesomerism 141
21. Chemical Reactivity from the Viewpoint of Electronic Theory 165
22. Nuclear Magnetic Resonance and Chemical Constitution 186
BIBLIOGRAPHY 194
AUTHOR INDEX 195
SUBJECT INDEX 199

Bibliography

[The following books are recommended for further study.]

BRAND, J. C. D., and SPBAKMAN, J. C.. "Molecular Structure." Edward Arnold, London, 1960.
BRAUDE, E. A., and NACHOD, F. C., "Determination of Organic Compounds by Physical Methods," Vol. I. Academic Press, New York, 1955.
CARTMELL, E., and FOWLES, G. W. A., "Valency and Molecular Structure." Academic Press, New York, 1956.
COTTRELL, T. L., "The Strength of Chemical Bonds." Academic Press, New York, 1954.
COULSON, C. A., "Valence." Oxford Univ. Press (Clarendon), London and New York, 1951.
DAUDEL, R., LEFEBVRE, R., and MOSER, C., "Quantum Chemistry." Interscience, New York, 1959.
DEWAR, M. J. S., "The Electronic Theory of Organic Chemistry." Oxford Univ. Press (Clarendon), London and New York, 1949.
GLASSTONE, S., "Theoretical Chemistry," 2nd ed. Van Nostrand, Princeton, New Jersey, 1945.
HAHTMANN, H., "Theorie der chemischen Bindung auf quantentheoretischer Grundlage." Springer, Berlin, 1954.
HARTMANN, H., "Die chemische Bindung." Springer, Berlin, 1955. HINE, J., "Physical Organic Chemistry." McGraw-Hill, New York, 1956.
HÜCKEL, E., "Grundzüge der Theorie ungesättigter und aromatischer Verbindungen." Verlag Chemie, Berlin, 1938.
KAUZMANN, W., "Quantum Chemistry: An Introduction." Academic Press, New York, 1957.
KLAGES, F., "Lehrbuch der organischen Chemie," de Gruyter, Berlin, 1955.
Nachod, F. C., and Phillips, W. D., "Determination of Organic Structures by Physical Methods," Vol. II. Academic Press, New York, 1962.
PAULING, L., and WILSON, E. B., JR., "Introduction to Quantum Mechanics." McGraw-Hill, New York, 1935.
PULLMAN, B., and PULLMAN, A., "Les Theories Electroniques de la Chimie Organique." Masson, Paris, 1952.
WHBATLEY, P. W., "Determination of Molecular Structure," Oxford Univ. Press (Clarendon), London and New York, 1959.
WHELAND, G. W., "Resonance in Organic Chemistry." Wiley, New York, 1955.

Author Index

Numbers in parentheses are footnote numbers. They are inserted to indicate that the reference to an author's work is cited with a footnote number and his name does not appear on that page.

Agallidis, E., 127
Anderson, L. C., 54
Arndt, F., 55
Artmann, K., 77
Aschner, T. C., 177

Baker, J. W., 90, 92, 93
Bastiansen, O., 73
Bayliss, N. S., 155
Becker, F., 92
Bennewitz, K., 19
Berliner, E., 94
Bernstein, H. J., 193
Bhatnagar, S. S., 119
Bijvoet, J. M., 86
Bjerrum, N., 130
Bleaney, D., 193
Bloch, F., 186
Bohr, N., 9
Bolland, J. L., 94
Bondhus, F. J., 94
Born, M., 22, 46
Brand, J. C. D., 194
Braude, E. A., 73, 141, 153, 164, 194
Brockway, L. O., 53, 86
Erode, W. R., 89
Br0nsted, J. N., 129
Brooker, L. C. S, 157
Brown, H. C., 75, 128
Brown, W. G, 153
Buckles, R. E., 89

Calvin, M., 52, 89
Cartmell, E, 58, 194
Chirgwin, B. H., 169
Condon, E. U., 154
Cook, J. W., 71
Corson, B. B., 153
Cottrell, T. L., 194
Coulson, C. A., 65, 79, 89, 90, 169, 180, 194

Daudel, R., 17, 194
Davies, M. M., 52
Davisson, C. J., 14
de Broglie, L., 13, 14
Debye, P., 96
Dewar, M. J. S., 194

Einstein, A., 7
Eistert, B., 55, 142
Eucken, A., 131
Evans, M. G., 171
Eyring, H., 171

Farkas, L., 126
Farmer, E. H., 94
Ferguson, L. N., 179
Fischer, E. O., 84
Forster, T., 142
Fowles, G. W. A., 58, 194
Franck, J., 154
Franke, W., 125
Franzen, V., 177
Friedheim, G., 73
Fritz, H. P., 84

Geiger, M. G., 54
Gent, W. L. G., 79
Germer, H. C., 14
Gibling, T. W., 50
Glasstone, S., 194
Gordy, W., 86, 96
Goudsmit, S., 22
Gould, E. S., 173
Griffith, J. S., 84
Gutowsky, H. S., 192

Häfliger, 0., 75, 128
Hallwachs, W., 7
Hammett, L. P., 137
Hansen, W. W., 186
Hartmann, H., 194
Hartree, D. R., 62
Hedden, G. D., 153
Heidelberger, M., 71
Heisenberg, W., 11, 23, 57
Heitler, W., 33
Heller, G., 89
Henri, V., 27
Hertz, H., 7
Herzberg, G., 27, 86
Higginson, W. C. F., 178
Hine, J., 194
Hückel, E., 62, 79, 104, 142, 168, 194
Hückel, W., 95
Hughes, E. D., 94, 171, 177, 185
Hume-Rothery, W., 32
Hund, F., 59
Hutchison, C. A., Jr., 117
Hylleraas, E. A., 11

Ingold, C. K., 55, 94, 101, 102, 113, 185
Ingold, E. H., 102

Jackman, L. M., 193
Jacobson, P., 185
Jaffé, H. H., 140, 180
Jannakopoulos, T., 104
Johnson, P., 184
Jones, E. R. H., 153
Jordan, P., 27
Juliusburger, F., 171
Jung, B., 104

Kalckar, F., 127
Karagounis, G., 104
Karle, J., 53
Katz, H., 125
Kauzmann, W., 17, 25, 194
Kirkwood, J. G., 107, 136
Klager, K., 71
Klages, F., 69, 194
Knox, L., 70
Koch, H. P., 153
Koike, M., 192
Kolkmeijer, N. H., 86
Kortüm, G., 73
Kossel, W., 45, 47
Krauch, H., 177
Krishnan, K. S., 121
Kuhn, H., 155, 162, 164
Kuhn, R., 125, 144

Laar, C., 54, 184
Langevin, P., 122
LeBel, 44
Lefebvre, R., 17, 194
Lenard, P., 7
Lennard-Jones, J. E., 89, 117
Lewis, G. N., 45, 47
London, F., 33
Longuet-Higgins, H. C., 89, 180
Lonsdale, K., 121
Loudon, J. D., 71
Lowry, T. M., 102, 129
Lüttringhaus, A., 185

McDaniel, D. H., 75, 128
MacGillavry, C. H., 86
McWeeny, R., 58
Madelung, E., 46
Maier, W., 86
Markownikoff, W., 174
Martell, A. E., 52
Masterman, S., 171
Mathur, K. M., 119
Mecke, R., 53
Meerwein, H., 165, 177
Merkel, E., 73
Midtdal, J., 11
Moelwyn-Hughes, E. A., 184
Moffit, W. E., 168
Moreland, W. T, 139
Moser, C., 17, 194
Müller, E., 123, 125
Müller-Rodloff, I., 123, 125
Mulliken, R. S, 90, 99, 136, 142, 150, 152, 180
Mumford, S. A., 50

Nachod, F. C., 194
Nathan, W. S., 90, 93
Nernst, W., 19

Odajima, A., 192
Onsager, L., 99
Orgel, L. E., 83, 84
Orville-Thomas, W. J., 96

Packard, M. E., 186
Parr, R. G., 180
Pascal, P., 119
Pauling, L., 17, 53, 58, 77, 99, 104, 121, 136, 194
Pearson, E. G., 89
Pekeris, C. L., 11
Pelzer, H., 171
Pfeiffer, P., 48
Phillips, J. W. C., 50
Phillips, W. D., 194
Piloty, O., 125
Platt, I. R., 155
Polansky, O. E., 71
Polanyi, M., 171
Pople, J. A., 193
Pound, R. V., 186
Pullman, A., 194
Pullman, B., 194
Purcell, E. M., 186

Raman, C. V., 121
Reed, J. B., 50
Reif, W., 185
Reppe, W., 71
Richardson, W., 153
Rieke, C. A., 142, 150
Roberts, J. D., 58, 139, 193
Robertson, P. W., 94
Rohde, W., 104
Rothbaum, H. P., 94
Ruark, A. E., 39
Rutherford, E., 9

Sachsse, H., 126
Saika, A., 192
Salein, L., 89
Schlenk, W, 126
Schlichting, O., 71
Schmidt, 0., 155
Schneider, W. G., 193
Schroedinger, E., 16
Schubert, W. M., 92
Schwab, G. M., 127
Schwartz, J. R., 185
Schwartzmann, L. H., 153
Seel, F., 94, 142
Selwood, P. W., 116, 120
Sidgwick, N. V., 48, 54
Simon, F., 19
Simpson, W. T., 155
Sklar, A. L., 142
Slater, J. C., 58
Smyth, C. P., 99
Sohma, J., 192
Sommerfeld, A., 10, ll(lc)
Sondheimer, F., 71, 153
Speakman, J. C., 194
Stevens, K. W. H., 193
Sugden, S., 50
Sutherland, G. B., 52
Svendson, M., 92
Sweeney, W. A., 92

Taft, R. W., Jr., 140
Taher, N. A., 94
Taylor, N. W., 123
Teller, E., 127
Thai, A., 126
Theilacker, W., 73, 104
Thomson, J. J., 7
Ting, I., 94
Toepel, T., 71
Toogood, J. B., 153
Topley, B., 171
Torrey, H. C., 186
Turner, R. B., 153

Uhlenbeck, G. E., 22
Urey, H. C., 39

van't Hoff, J. H., 44
Van Vleck, J. H., 36, 106, 120
Vivo, J. L., 193
Vogel, A. I., 50
Vogel, W., 125
Voitle, D. W., 153
von Baeyer, A., 54
von E. Doering, W., 70, 177

Walsh, A. D., 136
Waser, E., 71
Weickel, T., 126
Weinberg, I., 192
Weiss, J., 171
Wertz, J. E., 193
Wessel-Ewald, M. L., 104
Wheatley, P. W., 194
Wheland, G. W., 55, 58, 68, 69, 70, 86, 104, 185, 194
Whiffen, D. H., 86
Wiberg, E., 112
Wiegand, C., 73
Wigner, E., 127, 171
Wilkins, H., 50
Willstätter, R., 71
Wilms, H., 71
Wilson, E. B., Jr., 17, 194
Wittig, G., 82
Wolovsky, R., 71
Wooding, N. S., 178
Wyman, G. M., 89

Ziegler, K., 71, 105
Zimmermann, J. R., 192

Subject Index

Acenes, 146
Acetic acid, 69, 133
Acetoacetic ester, 54
Acetone, 145
Acetonitrile, 86, 87
Acetylene, 85, 136
Acridine, 163
Activated complex, 172
â-Alanine, 107
Albumin, 107
Alkali halides, lattice energies, 46
Alkyl halides, dipole moments, 101
Amino acids, 107
p-Aminobenzoic acid, 138
Aminobenzoic acids, 100
Aminocaproic acid, 107
p-Aminophenol, 185
p,p'-Aminostilbene, 88
Ammonia, 166, 178
Aniline, 69, 135, 170, 180
Anionoid reactions, 166
Anionotropic reaction, 184
Anisole, 113
Anthracene, 60, 64, 69, 121, 122, 146, 169, 170
Antibonding states, 151, 152
Aromaticity, 70
Aryl halides, dipole moments, 101
Atomic distance, 85
Atomic refractions, 110
Atomic susceptibilities, 119
Auxochromic group, 141
Azulene, 69, 148

Balmer series, 10
Bathychromic effect, 143, 144, 146
Beckmann rearrangement, 185
Benzaldehyde, 153
Benzene, 55, 60, 64, 68, 69, 70, 72, 73, 85, 87, 89, 90, 121, 122, 146, 147, 179, 180, 181
MO calculation, 62
resonance energy, 59
Benzoic acid, 69, 70, 134, 138
Benzofulvene, 150, 152
Benzophenone, 153
Benzophenone potassium, 126
Benzoquinone, 69
Beryllium compounds, 81
4R-Bicyclo-(2,2,2)-octane-1-oic acid, 139
Biphenyl, 60, 64, 69, 72, 73, 89, 122, 144, 146
Black body, 3
Bohr atomic model, 9, 29
Bohr magneton, 123, 124, 125, 190, 192
Boltzmann constant, 2
Boltzmann distribution, 188
ð-Bond, MO, 80
Bond order, 85, 86
Bond strength, 44
Bonding states, 151, 152
Boron compounds, 81
Bromoacetylene, 102
Bromobenzene, 182
l-Bromo-2-chloroethane, 177
l-Bromo-2,4-dinitrobenzene, 183
Bromoethylene, 102
Butadiene, 60, 64, 68, 69, 89, 151, 169
sec. Butanol, 173
Butene, 68
Butyric acid, 134

Camphenyl chloride, 184
Camphor, 177
Canonical structures, 67, 147, 148, 150
Carbanion, 178
Carbazole, 135
Carbonium ion, 177
Catalysis, 165
Charge distribution, 167, 170
Chelates, 52
Chemical bond, 43, 109
Chemical shift, 190
Chlorobenzene, 88, 99, 105, 176, 182
Chloroethylene, 136
Chromobenzene, 83
Chromophore, 141, 145
Chrysene, 67, 69, 121, 122
cis-Cinnamic acid, 75
trans-Cinnamic acid, 75
Claisen reaction, 185
Clausius-Mosotti equation, 96, 97
Cobalt complexes, 83
Color, 141
Combustion, heat of, 44, 67
Complex conjugate, 28
Complex salts, 48
Composite bond type, 49
Compton effect, 25
Conjugated double bonds, 149
Constitution, 141
Copenhagen interpretation, 22
Coplanarity, 66, 71, 104, 146
Copper acetylene, 138
Corpuscle theory, 8
Correspondence principle, 11
Coulomb attraction, 9, 46, 151
Coulomb integral, 34, 169
Coupling integral, 63
Covalent bond, 33
Covalent character, 106
Crotonic acid, 134
Cryptoionic reactions, 165, 177
Cyanine dyestuffs, 157, 162
Cycloheptatriene, 70
Cycloheptatrienyl bromide, 70
Cycloheptatrienyl cation, 72
1,3-Cyclohexadiene, 68
Cyclohexane carboxylic acid, 134, 140
1,3,5-Cyclohexatriene, 68
Cyclohexene, 68
Cyclooctatetraene, 69, 71
Cyclopentadiene, 69, 89
Cyclopentadienyl anion, 72
Cyclopentene, 68

De Broglie wave concept, 13
Debye equation, 99
Degeneracy, 32, 36, 61
Delocalization, 68, 91, 155, 167
Desmotropism, 54
Determinant, 63
Dewar structures, 60
Diacetylene, 87
Diamagnetic shielding constant, 189
Diamagnetism, 114, 115, 121
3,3'-Diaminodimesityl, 75
p-Diaminodiphenyl, 185
Diamond, 86, 121
specific heat, 6
Diazomethane, 87
Diazonium ion, 176, 183, 184
Dibenzal acetone, 56
Dibenzofulvene, 150, 152
m-Dichlorobenzene, 99
o-Dichlorobenzene, 99
p-Dichlorobenzene, 99, 100, 127
1,1-Dichloroethane, 174
Dichlorosulfoxide, 50
Dicyclopentadienyl beryllium, 84
Dielectric constant, 97
Dielectric polarization, 96
Diethylsulfone, 49
6,15-Dihydroanthracene, 146
Diketopiperazine, 86
Dimethyl ether, 113, 143
trans-Dimethylethylene, 90
cis-Dimethylethylene carboxylic acid, 136
trans-Dimethylethylene carboxylic acid, 136
Dimethyl phenylamine, 113
Dinaphthofulvene, 152
Dinitrodiphenic acid, 73, 75
Diphenylacetylene, 69
Diphenylamine, 74, 135, 170
Diphenyl ether, 113
Diphenylhydrazine, 185
Diphenylmethane, 74, 136, 146
Diphenylpolyenes, 144
Dipole moment, 95
Directional chemical bond, 44
Dissociation constants, 128, 130
Dulong-Petit law, 5

Eigenfunctions, 17, 19
Eigenvalues, 17
Electron gas model, organic compounds, 42, 155
Electron interference, 15
Electron in the box, 155, 159, 160
Electron paramagnetic resonance, 192, 193
Electron, wave nature, 14
Electronegativity of elements, 96
Electronic charge, spatial distribution, 28
Electronic configuration, elements, 39-41
Electronic density distribution, 30
Electrophilic substitution, 166, 170, 176
Elements, electronic configuration, 39-41
Elimination reactions, 178
Ethane, 85, 86, 92
Ethanol, 189
Ethylbenzene, 68
Ethyl benzoate, 181
Ethyl bromide, 102
Ethyl chloride, 101
Ethylene, 68, 90, 136, 148, 149, 151
Ethylvinylether, 68
Equilibria, 128
Equipartition principle, 3
Exchange degeneracy, 36
Exchange integral, 34, 61
Exclusion principle, see Pauli principle

Ferrocene, 83
Fluorene, 69
Fluorobenzene, 182
Forbidden states, 9
Formic acid, 52, 69, 70, 133
Franck-Condon principle, 154
Free radicals, 193
Friedel-Crafts reaction, 176
Fulvene, 147, 150, 152
Furane, 68, 69

g-factor, 192
Glycine, 107
Glyoxal, 89
Graphite, 85, 89, 122

Hamiltonian operator, 59
Hammett equation, 137, 138, 139
Hammett's ó values, 139, 140
Heisenberg uncertainty principle, 24, 191
Helium, ionization energy, 11
Heteropolar compounds, 46
Hexaglycine, 107
Hexamethylbenzene, 69
Hexaphenyl, 144
Hexaphenylethane, 104, 124
Hexatriene, 64, 151
Homopolar'bond, 33, 47
Hooke's law, 18
Hückel's rule, 72, 79
Hund's rule, 77, 117
Hybridization, 76, 85
Hydrochloric acid, 105
ortho-Hydrogen, 126, 127
para-Hydrogen, 126, 127
Hydrogen bonds, 51
Hydrogen fluoride, 51, 106
Hydrogen halides, dipole moments, 112
Hydrogen molecule, 33
energy curves, 36
Hydrogenation, heat of, 67
1-Hydroxyanthraquinone, 52
Hydroxybenzaldehyde, 51
Hyperconjugation, 90, 92, 103, 133, 173, 181
Hyperfine structure, 193
Hypsochromic effect, 143

Indigo, 88, 89
Indole, 135
Induction effect, 101
Iodobenzene, 113
Ionization constants, 128, 130
Isobornyl chloride, 184
Isobutyl group, hyperconjugation, 94
Isoelectronic compounds, 112
Isomers, 44
Isopropyl bromide, 174, 178

Kekule structures, 60
Ketylene, metal, 126

Langevin equation, 120, 122
Laplace operator, 19
Larmor-Langevin equation, 120, 121
Larmor frequency, 186, 187, 188
Larmor precession, 192
Lattice energies, alkali halides, 46
Lenz' rule, 115
Light theory, 7
Limiting formula, 57
Lyman series, 10

Magnetic permeability, 116
Magnetic quantization, 22
Magnetic susceptibility, 109, 121
Magnetogyric ratio, 187
Markownikoff rule, 174, 175
Matrix mechanics, 11
Maxwell relationship, 98
Menthol, 173
Meri-quinoid structure, 141
Mesitylene, 68, 69, 74
Mesomeric effect, 103
Mesomerism, 45, 54, 55, 132, 134, 141, 153, 182
Metals, electron theory, 42
Methane, 136
Methanol, 134
Methylacetylene, 86, 91
Methylamine, 135
Methyl bromide, 171
Methyl chloride, 101, 105
Methylcyclohexanol, 173
Methylene blue, 163
Methylene red, 163
Methyl group, hyperconjugation, 91
Methyl iodide, 113
Methylisocyanate, 88
Methyl mercaptan, 113
Methylpropiolic acid, 134
Methyl sulfate, 50
Michael reaction, 179
Microwave spectra, 108
Mica, electron interference, 15
Microprocesses, 26
Molar polarization, 97
Molar refraction, 109
Molar susceptibility, 117, 122
Molecular orbital theory, 58, 167, 169

Naphthalene, 60, 64, 67, 69, 72, 89, 121, 122, 146, 148, 169, 170, 176
á-Naphthylamine, 69
Nickel complexes, 83
Nitration, 176, 183
p-Nitroaniline, 103
m-Nitroanisole, 182
Nitrobenzene, 90, 182
Nitrogen pentachloride, 82
Nitronium ion, 176
p-Nitrophenol, 54, 135
Nitrophenols, 52
p-Nitrosophenol, 54
p-Nitrotoluene, 90
Nuclear magnetic resonance, 186
Nucleophilic addition, 177, 178
substitution, 183, 184
N -> V transitions, 152

Octatetraene, 89
Octatriene, 149
Octet theory, 47
2-Octyl iodide, 171
Olefins, polymerization, 178
Onsager equation, 99
Oscillator, 3
Overlap integral, 34

Palladium complexes, 83
Parachor, 50
Paramagnetism, 114, 115, 118, 124
Paschen series, 10
Pauli principle, 34, 37
Pentacene, 124, 145
Pentaphenylpentadienyl, 124
Per cent double bond character, 89, 102, 167
Per cent ionic character, 105, 106
Periodic system, 38
Perylene, 145
Phenanthrene, 64, 122
Phenol, 134
Phenylacetylene, 69
Phenyl bromide, 102
Phenylcarboxylic acid, 136
á-Phenylethylalcohol, 173
Phenylhydroxylamine, 185
Phenyl mercaptan, 113, 175
Phenyltrimethylammonium ion, 181
Phosgene, 88
Photoelectric effect, 7, 13
Photon, 7
Planarity, 68, 103, 153
Platinum complexes, 83
Polar coordinates, 20
Polarizability, 97, 109, 112
Polymerization, olefins, 178
Polymers, 192
Polypeptides, 53
Porphyridin, 125
Potassium chloride, 105
Potassium tetrafluoroborate, 48
Potential energy curves, 172
Predissociation spectra, 27
Propionic acid, 133
n-Propyl bromide, 174
Propyl chloride, 101
Propylene, 68, 174, 175, 178
Pyrene, 122
Pyridine, 72, 121
Pyridinium, quaternary salt, 93
ã-Pyrones, 56
Pyrrole, 69, 72, 135

Quantum, 1
Quantum mechanics, 1
Quinoid structures, 141, 180, 182

Racemization, 171, 173
Radiation laws, 1
Rare earths, 193
Rare gas configuration, 47
Reactivity, 165
Rearrangement reactions, 177, 184, 185
Resonance, 54, 66
energy, 66, 140, 147, 151
hybrid, 58
integral, 63, 169
Rutherford atomic model, 9
Rydberg constant, 10

Schlenck's hydrocarbon, 125
Schroedinger equation, 16
Secular equations, 63
p-Semi-quinone, 193
Silver, specific heat, 6
Singlet state, 36
Solvolysis, 173
Spatial distribution of electronic charge, 28
Specific Heat, 5
Spin-spin splitting, 192
Stark effect, 108
Stationary states, 9
Stereoisomers, 44
Steric hindrance, 66, 149
Stilbene, 69
cis-Stilbene, 72
trans-Stilbene, 72
Styrene, 68
Sulfones, 49
Sulfoxides, 49
Susceptibility, atomic, 119
molar, 117, 122

Tautomerism, 55, 184
Tetracene, 144
2,2',6,6'-Tetrachloro-4,4'-bisdiphenyl-methylbiphenyl, 125
Tetramethylammonium iodide, 166
Tetramethylethylene, 68
Tetraphenylnaphthacene, 124
2,3,5,6-Tetramethylnitroaniline, 104
Thiophene, 69, 72, 121
Toluene, 69, 90, 181
Transition state, 94
Tribiphenylmethyl radical, 104, 124, 127
Trichloromethylbenzene, 181
2,3,4-Triketopentane, 146
Trimethylamine, 111, 113
Trimethylnitrosomethane, 145
Trimethyl phosphine, 113
p-Trinitrotriphenylmethane potassium, 136
Triozonide, 56
Triphenyl, 122
Triphenylamine, 135, 170, 171
1,3,5-Triphenylbenzene, 67, 69
Triphenylene, 144
Triphenylmethane, 136
Triphenylmethyl, 124, 127
Triphenyl phosphine, 113
Triplet state, 36
Tropolone, 69, 71
Tropylium bromide, 70
Tschitschibabin's hydrocarbon, 123, 125, 127

Uncertainty principle, 24, 191
Urea, 69

Valence bond theory, 58, 167, 182
Variation method, 58
Vinylamine, 102
Vinyl bromide, 102
Vinyl chloride, 88, 175
Vinylether, 68

Wagner-Meerwein rearrangement, 177, 184
Wave mechanics, 16
Wave theory, 8

X-ray interference, 15
o-Xylene, 68, 69

Zeeman effect, 32
Zero point energy, 27