title: Excited states in electron-transfer reaction products: ultrafast relaxation dynamics of an isolated acceptor radical anion.
abstract: The spectroscopy and ultrafast relaxation dynamics of excited states of the radical anion of a representative charge-transfer acceptor molecule, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, have been studied in the gas phase using time-resolved photoelectron spectroscopy. The photoelectron spectra reveal that at least two anion excited states are bound. Time-resolved studies show that both excited states are very short-lived and internally convert to the anion ground state, with the lower energy state relaxing within 200 fs and a near-threshold valence-excited state relaxing on a 60 fs time scale. These excited states, and in particular the valence-excited state, present efficient pathways for electron-transfer reactions in the highly exergonic inverted region which commonly displays rates exceeding predictions from electron-transfer theory.
authors.affiliation: Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, United Kingdom.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Horke
authors.forename: Gareth M
authors.initials: GM
authors.lastname: Roberts
authors.forename: Jan R R
authors.initials: JR
authors.lastname: Verlet