RATE CONSTANTS FOR THE GAS-PHASE REACTIONS OF CL ATOMS WITH A SERIES OF HYDROFLUOROCARBONS AND HYDROCHLOROFLUOROCARBONS AT 298-K+/-2-K

A relative rate method has been used to determine rate constants for the gas-phase reactions of a series of hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) at 298 +/- 2 K and atmospheric pressure of air. Based on a rate constant for the reaction of the Cl atom with CH4 of (1.0 +/- 0.2) x 10(-13) cm3 molecule-1 s-1 at 298 K, the following Cl atom reaction rate constants (in units of 10(-15) cm3 molecule-1 s-1) were obtained: CH3F, 340 +/- 70; CH3CHF2, 240 +/- 50; CH2FCl, 110 +/- 25; CHFCl2, 21 +/- 4; CHCl2CF3, 14 +/- 3; CHFClCF3, 2.7 +/- 0.6; CH3CFCl2, 2.4 +/- 0.5; CHF2Cl, 2.0 +/- 0.4; CH2FCF3, 1.6 +/- 0.3; CH3CF2Cl, 0.37 +/- 0.08; and CHF2CF3, 0.24 +/- 0.05. These Cl atom reaction rate constants are compared with literature data and with the corresponding OH radical reaction rate constants.