KINETICS OF THE REACTIONS OF CF3O RADICALS WITH CO AND H2O

The techniques of pulsed laser photolysis/pulsed laser-induced fluores cence and discharge flow/chemical ionization mass spectroscopy have be en employed to study the reactions CF3O + H2O --> CF3OH + OH and CF3O + CO (+M) --> products (+M). No reaction could be observed between CF3 O and H2O at both 298 and 381 K, yielding upper limits of k(3)(298 K) less than or equal to 1 x 10(-16) and k(3)(381 K) less than or equal t o 2 x 10(-16) cm(3) molecule(-1) s(-1). The rate coefficient, k(4), fo r the reaction of CF3O with CO was observed to be dependent upon press ure, analogous to the OH + CO reaction. The high-pressure limiting rat e coefficient was found to exhibit a weak positive temperature depende nce with k(4 infinity)(298 K) (6.8 +/- 1.2) x 10(-14) cm(3) molecule(- 1) s(-1). A limit of less than or equal to 2 x 10(-15) cm(3) molecule( -1) s(-1) for the pressure independent pathway was also obtained and a limit of less than or equal to 4 x 10(-16) cm(3) molecule(-1) s(-1) w as determined for the bimolecular path yielding CF3 and CO2 as product s, both at 298 K. Information on the OH + CF3OOCF3, OH + CF3O, and CF3 OO + CO reactions and on the products of the 248 nm photolysis of CF3O OCF3 was also obtained. The atmospheric implications of the results ar e discussed.