Electronically Excited S₂(<i>x</i>¹Δ_<i>g</i>) in the Disproportionation and Abstraction Reactions of Sulfur Radicals

Abstract

Abstract A transient spectrum of S 2 which has been observed before only in emission and assigned to the b 1 Δ u → x 1 Δ g transition has been detected in flashed H 2 S 2 , H 2 S, COS, CS 2 , and SPF 3 indicating the presence of S 2 ( x 1 Δ g ) molecules in these systems. By detailed kinetic studies S 2 ( x 1 Δ g ) has been shown to arise from the self and cross disproportionation reactions of the SH and S 2 H radicals and from the abstractive attack of S( 1 D ) atoms on COS and SPF 3 . The recombination reaction of S( 3 P ) atoms in the presence of CO 2 also produces S 2 ( x 1 Δ g ).