title: Ultrafast photodynamics of furan.
abstract: Ultrafast photodynamics of furan has been studied by time-resolved photoelectron imaging (TRPEI) spectroscopy with an unprecedented time resolution of 22 fs. The simulation of the time-dependent photoelectron kinetic energy distribution (PKED) has been performed with ab initio nonadiabatic dynamics "on the fly" in the frame of time-dependent density functional theory. Based on the agreement between experimental and theoretical time-dependent photoelectron signal intensity as well as on PKED, precise time scales of ultrafast internal conversion from S(2) over S(1) to the ground state S(0) of furan have been revealed for the first time. Upon initial excitation of the S(2) state which has π-π* character, a nonadiabatic transition to the S(1) state occurs within 10 fs. Subsequent dynamics invokes the excitation of the C-O stretching and C-O-C out of plane vibrations which lead to the internal conversion to the ground state after 60 fs. Thus, we demonstrate that the TRPEI combined with high level nonadiabatic dynamics calculations provide fundamental insight into ultrafast photodynamics of chemically and biologically relevant chromophores.
authors.affiliation: Chemical Dynamics Laboratory, RIKEN Advanced Science Institute, Hirosawa 2-1, Wako, Saitama, 351-0198, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fuji
authors.forename: Yoshi-Ichi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Takuya
authors.initials: T
authors.lastname: Horio
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Roland
authors.initials: R
authors.lastname: Mitrić
authors.forename: Ute
authors.initials: U
authors.lastname: Werner
authors.forename: Vlasta
authors.initials: V
authors.lastname: Bonačić-Koutecký
mesh_terms: D000042:Absorption; D005663:Furans / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D011789:Quantum Theory
chemical_list: D005663:Furans; C039281:furan