Formation of vibrationally excited OH radicals in the O ( 1D) + H 2S reaction

Abstract

The rate constant, macroscopic branching ratio and vibrational distribution for the reaction O( 1 D) + H 2 S→OH + SH were measured. Temporal dependencies of the OH radical concentration in different ro-vibronic states were monitored by the LIF technique after laser flash photolysis of ozone which generated O( 1 D) atoms. The total rate constant was found to be (2.2±0.5 ) × 10 −10 cm −3 molecule −1 s −1 . The relative fraction of channel producing OH and SH radicals is 0.26 ± 0.04. The vibrational distribution of OH radicals P (ν=0): P (ν= 1) : P (ν=2) : P (ν=3) : P (ν=4) : P (ν=5) = 0.19:0.21:0.26:0.2:0.11:0.03 is similar to that for the reaction of O ( 1 D) atoms with H 2 , CH 4 and NH 3 which indicates the similar dynamics of these reactions.