The temperature dependence of the rate constants for the reactions F + CH3F and F + CH2F2

The temperature dependence of the rate constants for the reactions F + CH3F and F + CH2F2 has been determined by a competitive method using the F + D2 reaction as a reference reaction. Ratios of rate constants kF+CH3F/kF+D2 and kF+CH2F2/kF+D2 were determined by a discharge–flow–mass spectrometric technique at four temperatures in the ranges 189–298 and 182–298 K for the two reactions, respectively. These ratios were combined with recommended values for kF+D2 to obtain absolute values for kF+CH3F and kF+CH2F2. The present results are compared with previous published results, which are available almost exclusively only for room temperature.