Photodissociation dynamics of OCS and CS2 adsorbed on water ice films at 193 nm

Photodissociation dynamics of OCS and CS2 adsorbed on water ice films at 90 K was investigated at 193 nm by measuring the time-of-flight spectra of photodissociated S(1D) and S(3P) atoms. The translational energy distributions are well represented by a combination of Gaussian and Maxwell–Boltzmann (M–B) distributions corresponding to the fast and slow time-of-flight components, respectively. Formation of the sulfur dimer on the ice surface is proposed as a secondary photoproduct. The fine-structure branching ratios of S(3PJ) from OCS and CS2 adsorbed on H2O or D2O water ice films were also determined.