Does the HO 2 radical react with H 2 S, CH 3 SH, and CH 3 SCH 3 ?

The kinetics of the title reactions were investigated in a discharge flow tube by using laser magnetic resonance detection of HO 2 . The upper limits for the bimolecular rate constants for the reactions of HO 2 with H 2 S ( k 1 ), CH 3 SH ( k 2 ), and CH 3 SCH 3 ( k 3 ) are <3 × 10 −15 , <4 × 10 −15 , and <5 × 10 −15 cm 3 molecule −1 s −1 , respectively, at 298 K. Our upper limit for k 1 is three orders of magnitude lower than the previously reported value. Measurements at higher temperatures also yield similar upper limits. Our results suggest that HO 2 is not an important oxidant for these reduced compounds in the atmosphere. © 1994 John Wiley & Sons, Inc.