Using laser flash photolysis/transient absorption technique for the study of two photon photodissociation of carbon disulfide in acetonitrile solution at 266 nm, the transient UV-Vis absorption spectrum of Rydberg state CS2 （6sσg） within 240-370 nm and subsequent dissociation product CS （α^3П） with the maximum absorption at 260 nm were directly observed. The lifetime of CS （α^3П） in the nitrogen and oxygen saturated solution is also studied in our experiment.
The laser flash photolysis technique is em- ployed to investigate the reaction mechanism of CS2 with ·OH in the nitrogen-saturated aqueous solution. By comparison of the transient absorption spectra obtained at different phases and pHs and through the addition of proper radical cation scavenger, CS2 is determined to react with ·OH to form ·CS2OH adduct, instead of the CS2+ radical cation. At pH 1―5, ·CS2OH decomposes into COS and ·HS, while at pH>5, it further reacts with OH- to form CS2O-. The tem- perature dependent kinetics for the reaction CS2 + ·OH → ·CS2OH is also reported in this paper with an estimated activation energy of (26.9±1.0) kJ·mol?1.
