Collect. Czech. Chem. Commun. 1988, 53, 1902-1909

Theory of nonradiative decay from the lowest singlet state of benzene: Excess energy dependence

Makoto Takahashia, Tadaaki Ikomaa, Yuichi Fujimuraa, Azumao Toyotab and Takeshi Nakajimac

a Department of Chemistry, Faculty of Science, Tohoku University, Sendai 980, Japan
b The Liberal Arts and Science, Yamagata University, Yamagata 990, Japan
c Tohoku Dental University, Koriyama 963, Japan


A time-independent Green function formalism is developed to study the excess energy dependence on the nonradiative decay in the S1 state of benzene. Effects of purely electronic relaxation (internal conversion, IC) and intramolecular vibrational redistribution, IVR, are taken into account at the same time. Model calculations show that the drastic increase in the nonradiative decay rate at around 3 000 cm-1 excess energy is due to the same onset of both IC and IVR rates. Our theory can explain the difference in rate constant between IVR and IC observed by Moss and Parmenter.