Dynamics at conical intersections: The influence of O–H stretching vibrations on the photodissociation of phenol.
- Resource Type
- Article
- Authors
- Hause, Michael L.; Yoon, Y. Heidi; Case, Amanda S.; Crim, F. Fleming
- Source
- Journal of Chemical Physics. 3/14/2008, Vol. 128 Issue 10, p104307. 8p. 1 Diagram, 4 Graphs.
- Subject
- *DYNAMICS
*PHOTODISSOCIATION
*PHENOLS
*SPECTRAL energy distribution
*PHOTONS
*DISSOCIATION (Chemistry)
*MOLECULES
*ELECTRONIC excitation
- Language
- ISSN
- 0021-9606
Comparing the recoil energy distributions of the fragments from one-photon dissociation of phenol-d5 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-d5 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-d5 radicals. The additional energy deposited in electronic excitation of the radical reduces the energy available for relative translation. [ABSTRACT FROM AUTHOR]