title: Dynamics at conical intersections: the influence of O-H stretching vibrations on the photodissociation of phenol.
abstract: Comparing the recoil energy distributions of the fragments from one-photon dissociation of phenol-d(5) with those from vibrationally mediated photodissociation shows that initial vibrational excitation strongly influences the disposal of energy into relative translation. The measurements use velocity map ion imaging to detect the H-atom fragments and determine the distribution of recoil energies. Dissociation of phenol-d(5) molecules with an initially excited O-H stretching vibration produces significantly more fragments with low recoil energies than does one-photon dissociation at the same total energy. The difference appears to come from the increased probability of adiabatic dissociation in which a vibrationally excited molecule passes around the conical intersection between the dissociative state and the ground state to produce electronically excited phenoxyl-d(5) radicals. The additional energy deposited in electronic excitation of the radical reduces the energy available for relative translation.
authors.affiliation: Department of Chemistry, University of Wisconsin Madison, Madison, WI 53706, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Hause
authors.forename: Y
authors.initials: Y
authors.lastname: Heidi Yoon
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Case
authors.forename: F Fleming
authors.initials: FF
authors.lastname: Crim