The 193 nm photodissociation of CH2 = CClF

The photodissociation of CH2=CClF at 193 nm has been studied by product tra nslational spectroscopy. A total of five primary dissociation channels was detected for the products of Cl (fast), HCl, HF, Cl (slow), and F in the de creasing order of relative yield. Product translational energy distribution s have been measured for these reaction products. While a thermal-like dist ribution was detected for the slow Cl and F atoms, a nonthermal distributio n was determined for the fast Cl atom and the molecular elimination of HCl and HF. Apart from the fast Cl atom with anisotropy parameter beta=0.5, the remaining products recoil isotropically following photolysis with linearly polarized light. By analogy with the photodissociation of chloroethylenes, these products are found to originate from two potential energy surfaces. In addition to the primary dissociation channels, we have detected the seco ndary products of F+C2H2 from the internally excited alpha-fluorovinyl radi cal through a fast fragment isomerization. (C) 2000 American Institute of P hysics. [S0021-9606(00)00636-X].