Pronounced non-Condon effect as the origin of the quantum beat observed in the time-resolved absorption signal from excited-state cis-stilbene

The wavelength-dispersed time-resolved transient absorption measurements of [S.sub.1] cis-stilbene in a nonpolar solvent as well as numerical simulation based on the linear response theory is reported. The results offer insight into significance of the non-Condon effect in spectroscopy involving highly excited electronic states.