VACUUM ULTRAVIOLET PHOTODISSOCIATION AND PHOTOIONIZATION STUDIES OF CH3SCH3 AND CH3S

We have measured the translational energy releases of the laser photodissociation processes CH3SCH3 + h-nu (193 nm) --> CH3 + CH3S [process (1)] and CH3SCH2 + H [process (2)]; and CH3S + h-nu (193 nm) --> S + CH3 [process (3)]. The onsets of the translational energy distributions for photofragments of processes (1) and (2) allow the direct determination of 74.9 +/- 1.5 and 91 +/- 2.5 kcal/mol for the dissociation energies of the CH3-SCH3 and H-CH2SCH3 bonds at 0 K, respectively. The threshold observed for S formed by process (3) is consistent with the conclusion that the production of S(3P) is small compared to S(1D). The photoelectron-photoion coincidence (PEPICO) spectra for CH3SCH3+, CH3SCH2+, CH3S+ (or CH2SH+), and CH2S+ resulting from photoionization of CH3SCH3 have been measured in the wavelength region of 900-1475 angstrom. The PEPICO study allows the construction of a detailed breakdown diagram for the formation of CH3SCH2+, CH3S+ (or CH2SH+), and CH2S+ from energy-selected CH3SCH3+ ions.