Some Reactions of Ground-State (3P) and Electronically Excited (1D) Sulfur Atoms

Reactions of S(3P) and S(1D) have been studied by utilizing carbonyl sulfide photolysis as a source of both species. It has been shown that 46% ± 4% of the sulfur atoms generated in the photolysis of OCS in the 2250–2650-Å spectral region can react as S(3P), but that substantial portion of the S(3P) is likely produced by deactivating collisions of OCS molecules with S(1D). Both S(1D) and S(3P) react with CS2. The rate constant ratios for these reactions relative to the reactions with OCS have been determined as ∼ 1.9 and ∼ 2.4 × 102, respectively. Efficient isotopic exchange of S(3P) with CS2 is proposed to occur by means of CS3 formation in a reaction independent of pressure above 50 torr. The reaction of S(1D) with N2O yields N2, but kinetic complexities suggest the intermediate formation of a species such as N2OS. Measurement of the quenching of the N2 yield has led to the determination of the relative rates of collisional deactivation of S(1D) for several gases.