Rate constants for the gas-phase reactions of OH radicals with CH₃CHF₂ and CHCl₂CF₃ over the temperature range 295-388 K

Rate constants for the reactions of OH radicals with CH3CHF2 and CHCl2CF3 have been determined over the temperature range 295-388 K and a total pressure of 1 atm. The OH rate data were obtained using the absolute rate technique of pulse radiolysis combined with kinetic spectroscopy. The data can be fit to the Arrhenius expressions: k(OH + HFC-152a) = 3.9 X 10(-12) exp[(-1370 +/- 260)/T] cm3 molecule-1 s-1 and k(OH + HCFC-123) = 1.1 X 10(-12) X exp[(-940 +/- 200)/T] cm3 molecule-1 s-1. The results are compared to the available literature data and discussed in terms of reactivity trends and in the light of the important role CH3CHF2 and CHCl2CF3 play as alternatives to the fully halogenated chlorofluorocarbons.