Vibrational excitations in chloromethyl radical formed by the photodissociation of chlorobromomethane
- Department of Physics, Hubei Engineering University, Xiaogan City, Hubei Province 432000 (China)
- Environmental Science and Engineering Research Center, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055 (China)
Using velocity map ion imaging, the photodissociation of chlorobromomethane (CH{sub 2}BrCl) 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 ({sup 2}P{sub 1/2}) (denoted as Br{sup *}) and Br ({sup 2}P{sub 3/2}) (denoted as Br) for the dominant CH{sub 2}BrCl + hv → CH{sub 2}Cl + Br{sup *} and CH{sub 2}BrCl + hv → CH{sub 2}Cl + 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 CH{sub 2} s-stretch mode v{sub 1} has the most probability of excitation. While in the Br channel, the CH{sub 2} scissors mode ν{sub 2} 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 v{sub 5} (C–Br stretch mode) are also excited in the parent molecule.
- OSTI ID:
- 22255281
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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