title: Excited-state dynamics of trans,trans-distyrylbenzene: transient anisotropy and excitation energy dependence.
abstract: We report a study of excited-state dynamics of trans,trans-distyrylbenzene in hexane solution with femtosecond two-color transient absorption spectroscopy. A consistent model of two distinct excited states, S1 and X, connected by the 10 ps dynamics is proposed with the support from the analysis of excited-state anisotropy. An investigation on the 10 ps dynamics with varying excitation energy has been also conducted. In the assumption of fast intramolecular vibrational redistribution, a dependence of this nonradiative 10 ps process on intramolecular temperature in the S1 state has been analyzed. We have found that an effective mode of approximately 1270 cm-1 is responsible for the 10 ps dynamics. The analysis of both anisotropy and pump-dependent results further implies that a distribution of rotamers may exist in the X state. The result indicates a drastic different excited-state relaxation pathway than that of trans-stilbene.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, Taiwan 106.
authors.forename: Feng-Cheng
authors.initials: FC
authors.lastname: Hsu
authors.forename: Michitoshi
authors.initials: M
authors.lastname: Hayashi
authors.forename: Houng-Wei
authors.initials: HW
authors.lastname: Wang
authors.forename: Sheng Hsien
authors.initials: SH
authors.lastname: Lin
authors.forename: Juen-Kai
authors.initials: JK
authors.lastname: Wang