Photodissociation of 1,1- and 1,2-C2F2Cl2 at 193 nm by product translational spectroscopy

Abstract

In this work, we have investigated the photodissociation of 1,1- and 1,2-C2F2Cl2 (DCDFE) at 193 nm using product translational spectroscopy. Results show that both molecules undergo the competing dissociation of the C–Cl and the C=C bond ruptures with a branching ratio of approximately 1:∼0.3. For 1,1-DCDFE, a slow Cl component was detected in addition to the fast Cl product. In contrast, we observed no slow component for 1,2-DCDFE, but a pair of secondary products Cl+C2F2 from the internally excited fragment CF=CFCl. From the measured anisotropy and energy disposal of the products, we conclude that upon excitation to the ππ* state, both molecules dissociate primarily on the excited potential energy surface.