Theoretical study of the molecular properties and the formation kinetics of the FS(O2)OCO radical

Molecular and kinetics properties of the FS(O2)OCO radical have been studied. Equilibrium structure, harmonic vibrational frequencies, conformational mobilities, enthalpy of formation of this radical and the energetic of the reaction FSO3 + CO → FS(O2)OCO have been investigated at different levels of the density functional theory and of the Gaussian composite models. The standard enthalpy of formation for FS(O2)OCO is predicted to be ΔHf,298 = −155.0 kcal mol−1. In very good agreement with reported experimental values, a rate coefficient at 296 K of 3.6 × 10−17 cm3 molecule−1 s−1 and an activation energy of 7.6 kcal mol−1 have been calculated.