Rate constants for the reactions of OH radicals with CH3OCF2CF3, CH3OCF2CF2CF3, and CH3OCF(CF3)(2)

The rate constants for the reactions of OH radicals with CH3OCF2CF3, CH3OCF 2CF2CF3, and CH3OCF(CF3)(2) have been measured over the temperature range 2 50-430 K. Kinetic measurements have been carried out using the flash photol ysis, laser photolysis, and discharge flow methods combined respectively wi th the laser induced fluorescence technique. The influence of impurities in the samples was investigated by using gas-chromatography. The following Ar rhenius expressions were determined: k(CH3OCF2CF3) = (190(-0.61)(+0.90)) X 10(-12) exp[- (1510 +/- 120)/T], k(CH3OCF2CF2CF3) = (2.06(-0.45)(+0.58)) X 10(-12) exp[-(1540 +/- 80)/T], and k(CH3OCF(CF3)(2)) = (1.94(-0.3)(+0.48)) X 10(-12) exp[-(1450 +/- 70)/T] cm(3) molecule(-1) s(-1). (C) 1999 John Wil ey & Sons, inc.