Photodissociation dynamics of dichloroethenes

The nascent rotational distributions of HCl (υ=0, 1, and 2) generated 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 ionization technique combined with time-of-flight mass spectrometry. The rotational distributions of vibrationally excited HCl (υ=1 and 2) molecules were Boltzmann-type, while those of HCl (υ=0) could not be represented by a Boltzmann distribution and consisted of two components. These results suggest that there are more than two processes in the photodissociation of DCE. (author)