Table of Contents
Laser Chemistry
Volume 15, Issue 2-4, Pages 93-111

Photodissociation Mechanisms of Benzene Cluster Ions on the Excitation With hv = 0.5-3.0 eV

Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Fukuoka 812, Japan

Received 16 April 1994

Copyright © 1995 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The photodissociation of mass-selected benzene cluster ions, (C6H6)n+(n=28), is studied to elucidate the dynamics of dissociation and the mechanism of fragmentation. For (C6H6)2+, the average translational energy and the angular distributions of the photofragments are measured as a function of photon energy (hv). The photoexcitation to an upper bound state with hv = 2.81 eV results in statistical energy disposal. Regardless of the excitation to a dissociative state with hv = 1.17-1.62 eV, only a small fraction (at most 10%) of the available energy is partitioned into the translation. For (C6H6)n+ with n = 5-8, the average number of neutral molecules ejected following photoexcitation increases linearly with increasing hv until (C6H6)2+ is reached as the product. The result suggests that the photofragmentation proceeds via the sequential evaporation of neutral monomers rather than the direct ejection of a neutral cluster.