REACTIONS OF CH3S AND CH3SOO WITH O3, NO2, AND NO

The atmospherically important reactions of both CH3S and CH3SOO were e xamined using the technique of pulsed laser photolysis/laser-induced f luorescence. Rate coefficients for the reactions CH3S + 03 --> product s (1) and CH3S + NO2 --> CH3SO + NO (2) were measured to be k1(T) = (1 .98 +/- 0.38) X 10(-12) exp[(290 +/-40)/T] cm3 molecule-1 s-1 and k2(T ) = (2.06 +/- 0.44) x 10(-11) exp[(320 +/- 40)/T] cm3 MolecUle-1 s-1. The reactions of the weakly bound CH3SOO adduct with O3, NO2, and NO w ere studied at low temperatures. The rate coefficients for the adduct reactions are as follows: CH3SOO + 03 --> products (4), k4 < 8 X 10(-1 3) CM3 molecule-1 s-1 at T = 227 K; CH3SOO + NO2 --> products (5), k5 = (2.2 +/- 0.6) X 10(-11) CM3 molecule-1 s-1 at T = 227-246 K; and CH3 SOO + NO --> products (6), k6 = (1.1 +/- 0.4) x 10(-11) CM3 Molecule-1 s-1 from T = 227-256 K. The measured values of k5 and k6 were indepen dent of temperature and pressure over the limited ranges employed. The atmospheric implications of these findings are discussed.