Flash Photolysis of HiS

Abstract

Hydrogen atoms produced by flash photolysis of H2S are “hot” and react with CO2 by process (13). H + CO2→CO + OH, ΔH= 102 kJ mol–1(13)

Flash spectroscopy has been used to determine [SH] and [S2] as functions of time following flash photolysis of H2S diluted with CO2. The rate-determining step in the decay of SH is either (3) or (4), with k3= 1 × 10–11 or k4= 3 × 10–11 cm3 molecule–1 s–1. The removal of S2 occurs principally by reaction (8), which is third order over the range of pressures studied, and the order of magnitude of k8 is 2.5 × 10–30 cm6 molecule–2 s–1. H + SH→H2+ S (3), 2SH→H2S + S (4), 2S2+ CO2→S4+ CO2. (8)