Sulfur atom exchange in the reaction of SH radicals with S atoms

The structural and energetic properties of the HSS-->SSH transition state are examined using the single and double coupled-cluster method. The energy change for the isomerization reaction is estimated to be 31.7+/-1 kcal mol(-1). The results suggest that the reaction between SH radicals and S atoms should isotopically exchange because the isomerization barrier is significantly less than the S-S bond dissociation energy in the HSS radical.