title: Ultrafast dynamics of UV-excited imidazole.
abstract: The ultrafast dynamics of UV-excited imidazole in the gas phase is investigated by theoretical nonadiabatic dynamics simulations and experimental time-resolved photoelectron spectroscopy. The results show that different electronic excited-state relaxation mechanisms occur, depending on the pump wavelength. When imidazole is excited at 239.6 nm, deactivation through the NH-dissociation conical intersection is observed on the sub-50 fs timescale. After 200.8 nm excitation, competition between NH-dissociation and NH-puckering conical intersections is observed. The NH-dissociation to NH-puckering branching ratio is predicted to be 21:4, and the total relaxation time is elongated by a factor of eight. A procedure for simulation of photoelectron spectra based on dynamics results is developed and employed to assign different features in the experimental spectra.
authors: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany. crespo@kofo.mpg.de
authors: Rachel
authors: R
authors: Crespo-Otero
authors: Mario
authors: M
authors: Barbatti
authors: Hui
authors: H
authors: Yu
authors: Nicholas L
authors: NL
authors: Evans
authors: Susanne
authors: S
authors: Ullrich