Kinetics of the reaction of HSO with O3 at temperatures 273–423 K

The rate coefficient of the reaction of HSO with O3 at five temperatures in the range 273–423 K was determined by means of the discharge-flow/laser-induced-fluorescence technique. The laser-induced fluorescence of HSO was detected by the gated photon-counting technique; a detection limit ∼4×109 molecules cm−3 was achieved. The reaction was carried out under pseudo-first-order conditions with [O3]≫[HSO]; the rate coefficient was determined to be k=(4.7±1.0)×10−14 cm3 molecule−1 s−1 at 298 K, approximately 30% greater than, but within experimental uncertainty of the only previous measurement by Wang and Howard by means of the discharge-flow/laser-magnetic-resonance technique. The temperature dependence of the rate coefficient is expressed in the Arrhenius form, k(T)=(2.1±0.7)×10−12 exp[−(1120±320)/T] cm3 molecule−1 s−1.