Dynamics of C-Br bond dissociation in methyl 2-bromopropionate at 235 nm: A resonance-enhanced multiphoton ionization study

摘要

The dynamics of the C-Br bond dissociation on UV excitation of methyl 2-bromopropionate mainly to the (1)(n sigma(*)) state, repulsive in the C-Br bond, has been investigated, employing resonance-enhanced multiphoton ionization. Both the ground state and spin-orbits excited bromine atoms were detected, with the former being the major channel. Bromine fragments show bimodal translational energy distributions, with slow and fast (major) bromine atoms arising mainly from the ground and excited electronic states, respectively. The measured recoil anisotropy suggests isotropic angular distributions of bromine atoms. Molecular orbital calculations reveal an important role of avoided curve crossing on C-Br bond dissociation dynamics. (C) 2015 Elsevier B.V. All rights reserved.