Classical dynamics of the reaction of S(3 P) with O2(3Σ g -)

Quasiclassical trajectory calculations have been used to analyse the exchange reaction S(3 P) with O2(3Σ g -) using a recently reported potential energy surface for ground state SO2. The calculated macroscopic rate constants are 1·26 × 10-12 cm3 molecule-1 s-1 at 300 K and 4·97 × 10-12 cm3 molecule-1 s-1 at 450 K. These values span the experimental value 2·24 × 10-12 cm3 molecule-1 s-1 which was found to be independent of temperature in this range. An alternative method of calculation gives slightly higher values. Our finding of a positive activation energy suggests that the potential surface used is imperfect in the long range interaction region.