DOES THE HO2 RADICAL REACT WITH H2S, CH3SH, AND CH3SCH3

The kinetics of the title reactions were investigated in a discharge f low tube by using laser magnetic resonance detection of HO2. The upper limits for the bimolecular rate constants for the reactions of HO2 wi th H2S (k1), CH3SH (k2), and CH3SCH3 (k3) are <3 X 10(-15), <4 X 10(-1 5), and <5 x 10(-15) cm3 molecule-1 s-1, respectively, at 298 K. Our u pper limit for kl is three orders of magnitude lower than the previous ly reported value. Measurements at higher temperatures also yield simi lar upper limits. Our results suggest that HO2 is not an important oxi dant for these reduced compounds in the atmosphere. (C) 1994 John Wile y & Sons, Inc.