ATMOSPHERIC CHEMISTRY OF CF3CH2OCH2CF3 - UV SPECTRA AND KINETIC DATA FOR CF3CH(CENTER-DOT)OCH2CF3 AND CF3CH(OO-CENTER-DOT)OCH2CF3 RADICALS AND ATMOSPHERIC FATE OF CF3CH(O-CENTER-DOT)OCH2CF3 RADICALS

Pulse radiolysis transient UV absorption spectroscopy was used to stud y the ultraviolet absorption spectra (220-320 nm) and kinetics of CF3C H(.)OCH2CF3 and CF3CH(OO .)OCH2CF3 radicals at 296 K, At 230 nm sigma( CF3CH(.)OCH2CF3) = (1.95 +/- 0.24) x 10(-18) and sigma(CF3CH(OO .)OCH2 CF3) = (4.40 +/- 0.51) x 10(-18) cm(2) molecule(-1), Rate constants fo r the reaction of F atoms with CF3CH2OCH2CF3, the self-reactions of CF 3CH(.)OCH2CF3 and CF3CH(OO .)OCH2CF3 radicals, the association reactio n of CF3CH(.)OCH2CF3 radicals with O-2, and the reactions of CF3CH(OO .)OCH2CF3 radicals with NO and NO2 were (1.5 +/- 0.7) x 10(-11), (2.6 +/- 0.4) x 10(-11), (5.4 +/- 0.7) x 10(-12) (uncorrected for possible secondary chemistry), (2.3 +/- 0.3) x 10(-12), (1.45 +/- 0.4) x 10(-11 ), and (8.4 +/- 0.8) x 10(-12) cm(3) molecule(-1) s(-1), respectively. Using an FTIR technique, rate constants for the reaction of Cl atoms with CF3CH2OCH2CF3 and CF3C(O)OCH2CF3 were determined to be (7.1 +/- 0 .9) x 10(-13) and (9.4 +/- 1.3) x 10(-16) cm(3) molecule(-1) s(-1). Fi nally, it was determined that the atmospheric fate of CF3CH(O .)OCH2CF 3 radicals is decomposition via C-C bond scission to give CS radicals and 2,2,2-trifluoroethyl formate (CF3CH2OCHO) which occurs at a rate o f approximately 7 x 10(5) s(-1). The results are discussed with respec t to the atmospheric chemistry of CF3CH2OCH2CF3 and analogous compound s.