UV ABSORPTION-SPECTRUM OF CF3CFCLO2 AND KINETICS OF THE SELF-REACTIONOF CF3CFCL AND CF3CFCLO2 AND THE REACTIONS OF CF3CFCLO2 WITH NO AND NO2

The ultraviolet absorption spectrum of CF3CFClO2 and the kinetics of t he self reactions of CF3CFCl and CF3CFClO2 radicals and the reactions of CF3CFClO2 with NO and NO2 have been studied in the gas phase at 295 K by pulse radiolysis/transient W absorption spectroscopy. The UV abs orption cross section of CF3CFCl radicals was measured to be (1.78 +/- 0.22) x 10(-18) cm(2) molecule(-1) at 220 nm. The UV spectrum of CF3C FClO2 radicals was quantified from 220 nm to 290 nm. The absorption cr oss section at 250 nm was determined to be (1.67 +/- 0.21) x 10(-18) c m(2) molecule(-1). The rate constants for the self reactions of CF3CFC l and CF3CFClO2 radicals were (2.6 +/- 0.4) x 10(-12) cm(3) molecule(- 1) s(-1) and (2.6 +/- 0.5) x 10(-12) cm(3) molecule(-1) s(-1), respect ively. The reactivity of CF3CFClO2 radicals towards NO and NO2 was det ermined to (1.5 +/- 0.6) x 10(-11) cm(3) molecule(-1) s(-1) and (5.9 /- 0.5) x 10(-12) cm(3) molecule(-1) s(-1), respectively. Finally, the rate constant for the reaction of F atoms with CF3CFClH was determine d to (8 +/- 2) x 10(-13) cm(3) molecule(-1) s(-1). Results are discuss ed in the context of the atmospheric chemistry of HCFC-124, CF3CFClH. (C) 1994 John Wiley & Sons, Inc.