Reactions of HS with NO and NO2 at 298 K

Abstract

HS radicals have been generated by the photodissociation of H2S at 193 nm and their disappearance monitored by LIF. The reaction of HS with NO, like the analogous reaction of OH with NO, has been shown to involve a third body. The low pressure rate coefficients have been determined for He, Ar, and N2. The values are 2.1, 2.2, and 2.4×10−31 cm6 molecule−2 s−1, respectively, with estimated uncertainties of ±10%. The high pressure limit is (2.8±1.0)×10−11 cm3 molecule−1 s−1. The reaction with NO2 (HS+NO2→HSO+NO) is second order with a rate coefficient of (3.5±0.4)×10−11 cm3 molecule−1 s−1. An upper limit for the rate coefficient with O2 has been estimated (4×10−17 cm3 molecule−1 s−1).