title: Full observation of ultrafast cascaded radiationless transitions from S2(ππ(∗)) state of pyrazine using vacuum ultraviolet photoelectron imaging.
abstract: A photoexcited molecule undergoes multiple deactivation and reaction processes simultaneously or sequentially, which have been observed by combinations of various experimental methods. However, a single experimental method that enables complete observation of the photo-induced dynamics would be of great assistance for such studies. Here we report a full observation of cascaded electronic dephasing from S2(ππ(*)) in pyrazine (C4N2H4) by time-resolved photoelectron imaging (TRPEI) using 9.3-eV vacuum ultraviolet pulses with a sub-20 fs time duration. While we previously demonstrated a real-time observation of the ultrafast S2(ππ(*)) → S1(nπ(*)) internal conversion in pyrazine using TRPEI with UV pulses, this study presents a complete observation of the dynamics including radiationless transitions from S1 to S0 (internal conversion) and T1(nπ(*)) (intersystem crossing). Also discussed are the role of (1)Au(nπ(*)) in the internal conversion and the configuration interaction of the S2(ππ(*)) electronic wave function.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Horio
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Roman
authors.initials: R
authors.lastname: Spesyvtsev
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Ingle
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Yoshi-Ichi
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki