Table of Contents
Laser Chemistry
Volume 14, Issue 1-3, Pages 15-29

Photodissociation Dynamics of Arn+ Cluster Ions

1Department of Chemistry, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
2Department of Chemistry, College of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153, Japan

Received 23 March 1993

Copyright © 1994 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 time-of-flight (TOF) spectra of Ar+ and Ar fragments produced in the photodissociation of Arn+ (3 ≦ n ≧ 24) were measured at wavelength around 540 nm. The kinetic-energy and angular distributions of the neutral photofragments were obtained for n = 3, 9 and 24 by a simulation analysis of the measured TOF spectral profiles. The overall aspect of the photodissociation process of Arn+ is deduced from these distributions within the context of trimer ion core model; a linear Ar3+ core is solvated by neutral Ar atoms. For Arn+ with 4 ≦ n ≲ 14, direct dissociation of the Ar3+ chromophoric core gives rise to Ar+ and/or Ar fragments with a high kinetic energy release. For the larger Arn+ (n ≳ 14), the production of high-kinetic-energy fragments is suppressed; “evaporation” of the solvent Ar atoms is instead the dominant channel of photofragmentation.