Kinetic study of the reaction of chlorine atoms with bromomethane and D-bromomethane in the gas phase

Abstract

Abstract The kinetics of the gas-phase reactions of chlorine atoms with bromomethane CH 3 Br and D-bromomethane CD 3 Br was studied experimentally. The relative rate method was applied using Cl + CH 4 as the reference reaction. The rate constants for H-abstraction from CH 3 Br ( k H ) and D-abstraction from CD 3 Br ( k D ) were measured in the temperature range of 298–527 K and at a total pressure of 100 Torr. The temperature dependencies of the rate constants are described by the expressions: k H = (1.43 ± 0.22) × 10 −11 × exp(−1040 ± 30/ T ) and k D = (1.36 ± 0.31)×10 −11 × exp(−1595 ± 30/ T ) cm 3 molecule −1 s −1 . The kinetic isotope effect, described by the ratio k H / k D , was found to be (1.07 ± 0.14) × exp(555 ± 20/ T ).