Reaction Dynamics and Energy RedistributionView this Special Issue
R. Voltz, A. Boeglin, A. A. Villaeys, S. H. Lin, "Intramolecular Vibrational Relaxation in Electronically Excited States", Laser Chemistry, vol. 2, Article ID 357986, 17 pages, 1983. https://doi.org/10.1155/LC.2.253
Intramolecular Vibrational Relaxation in Electronically Excited States
A density matrix approach for describing intramolecular dynamics, with special application to vibrational relaxation in excited electronic states, is presented. We derive the master equations governing intramolecular transfer of excitation energy between the states in a zeroth-order basis defined by considering the excitation and detection conditions in the time-resolved experiments. It is shown that, in this formalism, the memory function plays a central role. We note that the form of intramolecular memory is determined by the importance of quantum mechanical mixing of the zeroth-order states. A distinction is made between the subsystems of states with strong and weak mixing properties; while the former account for quasiperiodic character of coherent motion, the latter display a Markovian behavior. The physical conditions fixing the relative importance of quasiperiodic and statistical dynamics in individual systems are discussed. In the application to time resolved intramolecular vibrational relaxation, special consideration is given to the nature of the initially excited doorway states and the intermode couplings. The symmetry restrictions and the possible role of rotational motion in vibrational relaxation are also discussed, before considering the recent results obtained by Zewail et al. with anthracene in the first excited singlet state.
Copyright © 1983 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.