Kinetic study of the reactions of chlorine atoms with fluoromethane and D-fluoromethane in the gas phase

The kinetics of the gas-phase reactions of chlorine atoms with fluoromethane (CH3F) and D-fluoromethane (CD3F) was studied experimentally. The relative rate method was applied using Cl + CH4 as the reference reaction. The rate constants for H-abstraction from CH3F (kH) and D-abstraction from CD3F (kD) were measured in the temperature range of 298–527 K and at a total pressure of 100 Torr using N2 as a diluent. The temperature dependency of the rate constants are described by the expressions: kH = (1.65 ± 0.26) × 10−11 × exp(−1150 ± 30/T) and kD = (1.21 ± 0.14) × 10−11 × exp(−1600 ± 25/T) cm3 molecule−1 s−1. The kinetic isotope effect, described by the ratio kH/kD, was found to be 6.2 ± 0.4 at room temperature.