Photodissociation of Oxalyl Chloride at 193 nm Probed via Synchrotron Radiation

Abstract

The photodissociation dynamics of oxalyl chloride, (ClCO)2, have been studied at 193 nm using photofragment translational spectroscopy with intense tunable vacuum-UV probe light provided by undulator radiation at the Advanced Light Source. Time-of-flight spectra for m/e 28 (CO+), 35 (Cl+), and 63 (ClCO+) are presented, along with translational energy distributions (P(E)) derived from forward convolution fitting. While the P(E) of (ClCO+) has a single sharp peak, those of (CO+) and (Cl+) show quite similar bimodal distributions. These observations suggest that the first step is an impulsive three-body dissociation yielding fast components of CO and Cl and that the remaining ClCO subsequently decomposes to give the slow components. This picture confirms a previous study of the photodissociation of oxalyl chloride at 230 nm using the photofragment imaging technique and provides more insight into the overall dynamics of the process. In addition, the tunable vacuum-UV photoionization has allowed for the measur...