Time resolved absorption spectra

Abstract

A theory for the time resolved electronic absorption spectrum of a molecule undergoing collisional vibrational relaxation is proposed. Symmetry forbidden and symmetry allowed transitions are considered. Changes in absorption spectra with time for some model cases are presented. Experimental data on the triplet–triplet absorption spectrum of anthracene are interpreted in the light of the theory. A brief discussion of time resolved emission spectra, and of fluorescence from high vibrational levels is also given.