Experimental and theoretical study of the recombination reaction FSO2 + O2 → FS(O2)OO

Abstract The kinetics of the recombination reaction FSO 2  + O 2  → FS(O 2 )OO (1) has been studied at 298 K. FSO 2 together with FSO 3 radicals were generated by 193 nm laser flash photolysis of FS(O 2 )O(O 2 )SF. The measured rate coefficient at one atmosphere total pressure is k 1  = (4.6 ± 0.6) × 10 −15  cm 3  molecule −1  s −1 . Molecular properties for the FS(O 2 )OO radical were calculated at the B3LYP/6-311+G(3df) and CCSD/6-311G(d) levels of theory. Consistent with the measured k 1 value, different density functional theory and G aussian -3 calculations predict an electronic energy barrier for reaction (1) close to 3 kcal mol −1 .