title: Time-resolved photoelectron imaging of S2 → S1 internal conversion in benzene and toluene.
abstract: Ultrafast internal conversion of benzene and toluene from the S(2) states was studied by time-resolved photoelectron imaging with a time resolution of 22 fs. Time-energy maps of the photoelectron intensity and the angular anisotropy were generated from a series of photoelectron images. The photoelectron kinetic energy distribution exhibits a rapid energy shift and intensity revival, which indicates nuclear motion on the S(2) adiabatic surface, while the ultrafast evolution of the angular anisotropy revealed a change in the electronic character of the S(2) adiabatic surface. From their decay profiles of the total photoelectron intensity, the time constants of 48 ± 4 and 62 ± 4 fs were determined for the population decay from the S(2) states in benzene and toluene, respectively.
authors.affiliation: Japan Science and Technology Agency, CREST, Sanbancho, Chiyoda-ku, Tokyo, Japan.
authors.forename: Yoshi-Ichi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Takuya
authors.initials: T
authors.lastname: Horio
authors.forename: Takao
authors.initials: T
authors.lastname: Fuji
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki