3.6 Nonadiabatic Transitions. Perturbation Theory. Probabilities
of Adiabatic and Nonadiabatic Transitions . . . . . . . . . . . . . . . . . . 70
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4 Photolysis of Free Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.1 Primary and Secondary Processes of Gas-Phase Photolysis.
Quantum Yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.2 Radiative Electronic Transitions. Selection Rules for Radiative
Electronic Transitions. Spin–Orbit Coupling and Spin-Forbidden
Radiative Electronic Transitions . . . . . . . . . . . . . . . . . . . . . . . . . 86
4.2.1 Allowed Radiative Electronic Transitions . . . . . . . . . . . . . 86
4.2.2 Forbidden Electronic Transitions. . . . . . . . . . . . . . . . . . . . 88
4.2.3 Spin–Orbit Coupling and Spin-Forbidden
Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.3 Absorption. Absorption Band Intensities. Einstein Absorption
and Stimulated Emission Coefficients. Beer-Lambert Law.
Oscillator Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.4 Luminescence. Radiative Lifetime. Einstein Spontaneous
Emission Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.5 Franck–Condon Principle for Bound–Bound and Bound-Free
Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.6 Intramolecular Perturbations. Selection Rules and Franck–
Condon Principle for Intramolecular Perturbation. Perturbations
Between Bound States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4.6.1 Perturbations Between Bound States of Diatomic
Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
4.6.2 Perturbations Between Bound States of Polyatomic
Molecules. Anomalously Long Radiative Lifetime
of Polyatomic Molecules . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.7 Electronic Predissociation of Di- and Polyatomic Molecules.
Types of Predissociation Processes . . . . . . . . . . . . . . . . . . . . . . . 134
4.7.1 Predissociation of Diatomic Molecules . . . . . . . . . . . . . . . 136
4.7.2 Predissociation of Polyatomic Molecules . . . . . . . . . . . . . . 140
4.8 Dissociation of Polyatomic Molecules. Long-Lived States
of Polyatomic Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
5 Energy Transfer in Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
5.1 Translational-Translational Energy Transfer
(T $ T Exchange) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
5.2 Rotational-Translational Energy Transfer (R $ T Exchange) . . . . 155
5.3 Vibrational Energy Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
x
Contents
of Adiabatic and Nonadiabatic Transitions . . . . . . . . . . . . . . . . . . 70
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4 Photolysis of Free Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.1 Primary and Secondary Processes of Gas-Phase Photolysis.
Quantum Yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.2 Radiative Electronic Transitions. Selection Rules for Radiative
Electronic Transitions. Spin–Orbit Coupling and Spin-Forbidden
Radiative Electronic Transitions . . . . . . . . . . . . . . . . . . . . . . . . . 86
4.2.1 Allowed Radiative Electronic Transitions . . . . . . . . . . . . . 86
4.2.2 Forbidden Electronic Transitions. . . . . . . . . . . . . . . . . . . . 88
4.2.3 Spin–Orbit Coupling and Spin-Forbidden
Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
4.3 Absorption. Absorption Band Intensities. Einstein Absorption
and Stimulated Emission Coefficients. Beer-Lambert Law.
Oscillator Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.4 Luminescence. Radiative Lifetime. Einstein Spontaneous
Emission Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
4.5 Franck–Condon Principle for Bound–Bound and Bound-Free
Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.6 Intramolecular Perturbations. Selection Rules and Franck–
Condon Principle for Intramolecular Perturbation. Perturbations
Between Bound States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4.6.1 Perturbations Between Bound States of Diatomic
Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
4.6.2 Perturbations Between Bound States of Polyatomic
Molecules. Anomalously Long Radiative Lifetime
of Polyatomic Molecules . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.7 Electronic Predissociation of Di- and Polyatomic Molecules.
Types of Predissociation Processes . . . . . . . . . . . . . . . . . . . . . . . 134
4.7.1 Predissociation of Diatomic Molecules . . . . . . . . . . . . . . . 136
4.7.2 Predissociation of Polyatomic Molecules . . . . . . . . . . . . . . 140
4.8 Dissociation of Polyatomic Molecules. Long-Lived States
of Polyatomic Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
5 Energy Transfer in Collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
5.1 Translational-Translational Energy Transfer
(T $ T Exchange) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
5.2 Rotational-Translational Energy Transfer (R $ T Exchange) . . . . 155
5.3 Vibrational Energy Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
x
Contents