title: Dynamics of charge-transfer-to-solvent precursor states in I- (water)n (n = 3-10) clusters studied with photoelectron imaging.
abstract: The dynamics of charge-transfer-to-solvent states are studied in I- (H2O)(n=3-10) clusters and their deuterated counterparts using time-resolved photoelectron imaging. The photoelectron spectra for clusters with n > or = 5 reveal multiple time scales for dynamics after their electronic excitation. An increase in the vertical detachment energy (VDE) by several hundred millielectronvolts on a time scale of approximately 1 ps is attributed to stabilization of the excess electron, primarily through rearrangement of the solvent molecules, but a contribution to this stabilization from motion of the I atom cannot be ruled out. The VDE drops by approximately 50 meV on a time scale of tens of picoseconds; this is attributed to loss of the neutral iodine atom. Finally, the pump-probe signal decays with a time constant of 60 ps-3 ns, increasing with cluster size. This decay is commensurate with the growth of very slow electrons and is attributed to autodetachment. Smaller clusters (n = 3, 4) display simpler dynamics. Anisotropy parameters are reported for clusters n = 4-9.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Aster
authors.initials: A
authors.lastname: Kammrath
authors.forename: Jan R R
authors.initials: JR
authors.lastname: Verlet
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Bragg
authors.forename: Graham B
authors.initials: GB
authors.lastname: Griffin
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Neumark