Decomposition and isomerization of the CH3CHClO radical: ab initio and RRKM study

Twelve unimolecular reaction channels of the CH3CHClO radical have been stu died using the ab initio G2-(MP2,SVP) method. The calculations detailed thr ee kinds of mechanisms, i.e., bond scission, intramolecular three-center el imination, and isomerization. On the basis of eb initio data, we performed multichannel (up to eight channels) RRKM calculation and numerical master e quation analysis. The energy-specific rate constants, k(E), and the thermal rate constants, k(T,P), were obtained. The three-center elimination of HCl from CH3CHClO was shown to be the dominant decomposition pathway. This fin ding provides theoretical evidence for the previous experimental result. Th e implication of our results was discussed in terms of understanding the at mospheric fate of the chemically activated or thermally balanced CH3CHClO r adicals.