The SH + CH3 product channel for the photodissociation of CH3SH at 204 nm was investigated using the sliced velocity map ion imaging technique with the detection of CH3 products using state selective (2+1) resonance enhanced multiphoton ionization (REMPI). Images were measured for CH3 formed in the ground and excited vibrational states (v2 = 0, 1, and 2) of the umbrella mode from which the correlated SH vibrational state distributions were determined. The vibrational distribution of the SH fragment in the SH + CH3 channel at 204 nm is clearly inverted and peaks at v = 1. The highly negative anisotropy parameter of the CH3 (v2 = 0, 1, and 2) products is indicative of a fast dissociation process for C–S bond cleavage. Two kinds of slower CH3 products were also observed (one of which was partly vibrationally resolved) that are assigned to a two-step photodissociation processes, in which the first step is the production of the CH3S (X2E) radical via cleavage of the S–H bond in CH3SH, followed by probe laser photodissociation of nascent CH3S radicals yielding CH3(X2A1, v2 = 0–2) + S(3Pj/1D) products.
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