An experimental and computational study of the reaction of ground-state sulfur atoms with carbon disulfide Available to Purchase

The pulsed laser photolysis/resonance fluorescence technique was used to study the reaction of S(³P_J) with CS₂ in an Ar bath gas. Over 290–770 K pressure-dependent kinetics were observed and low- and high-pressure limiting rate constants were derived as k₀ = (11.5–0.0133 T/K) × 10⁻³¹ cm⁶ molecule⁻² s⁻¹ (error limits ± 20%) and k_∞ = (2.2 ± 0.6) × 10⁻¹² cm³ molecule⁻¹ s⁻¹. Equilibration observed at 690–770 K yields a CS₂–S bond dissociation enthalpy of 131.7 ± 4.0 kJ mol⁻¹ at 298 K. This agrees with computed thermochemistry for a spin-forbidden C_2V adduct, estimated at the coupled-cluster single double triple level extrapolated to the infinite basis set limit. A pressure-independent pathway, assigned to abstraction, was observed from 690 to 1040 K and can be summarized as 1.14 × 10⁻¹⁰ exp(−37.0 kJ mol⁻¹/RT) cm³ molecule⁻¹ s⁻¹ with error limits of ± 40%. The results are rationalized in terms of a computed potential energy surface and transition state theory and Troe's unimolecular formalism.