Environmental assessment of CFC alternatives: Rate constants for the reactions of OH radicals with fluorinated compounds

The rate constants for the reactions of OH radicals with CF3OCHFCF3, and CF3CHFCF3 have been measured over the temperature range 250–430 K. Kinetic measurements have been carried out using the flash photolysis, and laser photolysis methods combined, respectively, with the laser induced fluorescence technique. The influence of impurities in the samples has been investigated by using gas chromatography. No sizable effect of impurities was found on the measured rate constants of these fluorinated compounds, if the purified samples were used in the measurements. The following Arrhenius expressions were determined: k(CF3OCHFCF3) = (4.39 ± 1.38) × 10−13 exp[−(1780 ± 100)/T] cm3 molecule−1 s−1, and k(CF3CHFCF3) = (6.19 ± 2.07) × 10−13 exp[−(1830 ± 100)/T] cm3 molecule−1 s−1.