PHOTODECOMPOSITION DYNAMICS OF MO(CO)6/SI(111)7X7 - CO INTERNAL STATE AND TRANSLATIONAL ENERGY-DISTRIBUTIONS

The rotational state and translational energy distributions of CO photodesorption products resulting from the 266 nm photolysis Of Mo (CO)6 adsorbed on Si(111) 7 X 7 with coverages in the multilayer regime are reported. State-resolved measurements show two desorption components with highly disparate energy dispositions. Results for different surface temperatures indicate that the energy content in one component reaches quasi-equilibration with the surface temperature, which is attributed to collisional relaxation of nascent photodecomposition products within the adlayer. The other component exhibits disparate rotational and translational ''temperatures'' that are significantly greater than, and independent of, the surface temperature. These nascent photodecomposition products are influenced by both energy quenching effects and dynamical constraints imposed by the existence of the adlayer.