title: Vibrational excitations in chloromethyl radical formed by the photodissociation of chlorobromomethane.
abstract: Using velocity map ion imaging, the photodissociation of chlorobromomethane (CH2BrCl) at 233-234 nm has been studied. The total translational energy distributions and the anisotropy parameters have been determined from the ion images of the photofragments Br ((2)P1/2) (denoted as Br(*)) and Br ((2)P3/2) (denoted as Br) for the dominant CH2BrCl + hv → CH2Cl + Br(*) and CH2BrCl + hv → CH2Cl + Br channels. Using an impulsive model invoking angular momentum conservation, the vibrational energy distributions of the chloromethyl radicals have been derived from the total translational energy distributions for the two channels. The study suggests that there are a number of vibrational modes of the chloromethyl radical to be excited in both of the two photodissociation channels. In the Br* channel, the CH2 s-stretch mode v1 has the most probability of excitation. While in the Br channel, the CH2 scissors mode ν2 is attributed to the highest peak of the vibrational energy curve of the chloromethyl radical. The results further imply that, following absorption of one UV photon of 234 nm, other vibrational modes besides v5 (C-Br stretch mode) are also excited in the parent molecule.
authors: Department of Physics, Hubei Engineering University, Xiaogan City, Hubei Province 432000, People's Republic of China.
authors: Qianguang
authors: Q
authors: Li
authors: Environmental Science and Engineering Research Center, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, People's Republic of China.
authors: Rongshu
authors: R
authors: Zhu
authors: Department of Physics, Hubei Engineering University, Xiaogan City, Hubei Province 432000, People's Republic of China.
authors: Jinjun
authors: J
authors: Lu
authors: Department of Physics, Hubei Engineering University, Xiaogan City, Hubei Province 432000, People's Republic of China.
authors: Xiu
authors: X
authors: Zhang
authors: Department of Physics, Hubei Engineering University, Xiaogan City, Hubei Province 432000, People's Republic of China.
authors: Bifeng
authors: B
authors: Tang