PHOTODISSOCIATION DYNAMICS OF H2S ISOLATED IN KRYPTON MATRICES

Photodissociation of H2S in krypton matrices is followed by monitoring laser-induced fluorescence from the SH photofragment. No evidence of an energy threshold for dissociation is observed. Quantum yields of dissociation, referenced to gas-phase absorption cross sections, increase nearly linearly from 0.04 +/- 0.01 to 0.25 +/- 0.08, in the spectral range between 266 and 193 nm (excess energies of 0.75-2.5 eV). In addition to the SH + H direct dissociation channel, production of S atoms is observed. The latter channel is ascribed to secondary, in-cage collisions between the SH and H fragments to produce S + H-2.