THE PHOTODISSOCIATION DYNAMICS OF DICHLOROETHENES AT 214 AND 220-NM

The nascent rotational distributions of HCl (upsilon = 0, 1, and 2) ge nerated in the photodissociation of three isomers of dichloroethenes ( DCE) at 214 and 220 nm were measured under molecular beam conditions. HCl molecules were probed by a (2+1) resonantly enhanced multiphoton i onization technique combined with time-of-flight mass spectrometry. Th e rotational distributions of vibrationally excited HCl (upsilon = 1 a nd 2) molecules were Boltzmann-type, while those of HCl (upsilon = 0) could not be represented by a Boltzmann distribution and consisted of two components. These results suggest that there are more than two pro cesses in the photodissociation of DCE. Cl(P-2(3/2)) and Cl(P-2(1/2)) could also be detected when DCE were photodissociated. The branching ratios of Cl(P-2(1/2) to Cl (P-2(3/2)) obtained in the present work w ere much larger than those obtained at 193 nm.