Journal of Physical Chemistry, Vol.98, No.16, 4312-4315, 1994
Reactions of Hydroxyl Radicals with Several Hydrofluorocarbons - The Temperature Dependencies of the Rate Constants for Chf2Cf2Ch(2)F (Hfc-245Ca), Cf3Chfchf2 (Hfc-236Ea), Cf3Chfcf3 (Hfc-227Ea), and Cf3Ch2Ch2Cf3 (Hfc-356Ffa)
Rate constants were determined for the gas-phase reactions of the hydroxyl radical with four hydrofluorocarbon compounds, CF3CHFCF3 (HFC-227ea), CF3CHFCHF2 (HFC-236ea), CHF2CF2CH2F (HFC-245ca), and CF3CH2CH2CF3 (HFC-356ffa), using the flash photolysis resonance fluorescence technique over the temperature range 260-365 K. Arrhenius expressions were derived for the four OH reactions : k(CF3CHFCF3) = 3.63 X 10-(13) exp[(1613 +/- 135)/T], k(CF3CHFCHF2) = 1.05 x 10(-12) exp[(1434 +/- 161)/T], k(CHF2CF2CH2F) = 2.87 X 10(-12) exp[(1661 +/- 170)/T],and k(CF3CH2CH2CF3) = 2.94 X 10(-12)exp[(1734 +/- 87)/T] cm(3) molecule(-1) s(-1). Tropospheric lifetimes for the four compounds were estimated to be 43, 7.8, 6.5, and 8.2 years, respectively.