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)
Zg. Zhang et al., 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), Journal of physical chemistry, 98(16), 1994, pp. 4312-4315
Rate constants were determined for the gas-phase reactions of the hydr
oxyl radical with four hydrofluorocarbon compounds, CF3CHFCF3 (HFC-227
ea), CF3CHFCHF2 (HFC-236ea), CHF2CF2CH2F (HFC-245ca), and CF3CH2CH2CF3
(HFC-356ffa), using the flash photolysis resonance fluorescence techn
ique 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(CF3CH2CH
2CF3) = 2.94 X 10(-12)exp[(1734 +/- 87)/T] cm(3) molecule(-1) s(-1). T
ropospheric lifetimes for the four compounds were estimated to be 43,
7.8, 6.5, and 8.2 years, respectively.