Rate constants for the reactions of OH radicals with CH3OCF2CHFCl, CHF2OCF2CHFCl, CHF2OCHClCF3, and CH3CH2OCF2CHF2

The rate constants for reactions of OH radicals with CH3OCF2CHFCl, CHF2OCF2 CHFCl, CHF2OCHClCF3, and CH3CH2OCF2CHF2 have been measured over the tempera ture range 250-430 K. Kinetic measurements have been carried out using the flash photolysis, laser photolysis, and discharge flow methods, combined wi th the laser-induced fluorescence technique to monitor the OH radical conce ntration. The influence of impurities contained in the samples has been exa mined by means of sample purification using gas chromatography, No sizable effect of impurities was found on the measured rate constants of these four halogenated ethers when the purified samples were used in the kinetic meas urements. The Arrhenius rate constants have been determined from the respec tive kinetic data as k(CH3OCF2CHFCl) = (2.59 +/- 0.51) x 10(-12) exp [-(12. 60 +/- 60)/T], k(CHF2OCF2CHFCl) = (7.46 +/- 1.85) x 10(-13) exp[-(1230 +/- 80)/T], k(CHF2OCHClCF3) = (1.12 +/- 0.18) x 10(-12) exp[-(1280 +/- 50)/T], and k(CH3CH2OCF2CHF2) = (2.57 +/- 0.44) x 10(-12) exp[-(730 +/- 50)/T] cm(3 ) molecule(-1) s(-1).