This grant, funded jointly by Special Projects in Chemistry and the Division of Materials Research provides support for the research of Profs. Stair and Weitz at Northwestern University. The objective of the research is to study, both experimentally and theoretically, the photodissociation dynamics of small molecules adsorbed on single-crystal insulator surfaces. Such information is of importance to the understanding of photochemistry at the gas-solid interface. In addition to studies of the adsorption and surface chemistry of the adsorbed molecular species, the experimental program will also focus on measurements of the angular distribution, the kinetic energy distribution and the rotational and vibrational distributions of the photodissociated fragments. The molecules to be studied were selected as representative examples of rapid direct and predissociative photodissociation mechanisms on the basis of gas phase photodissociation measurements. They also provide both atomic and molecular fragments that are amenable to high sensitivity detection as well as theoretical description. The magnesium oxide adsorbant surface was selected for its insulating properties,ease of handling and characterization and its chemical stability. Theoretical models to be developed will aim at calculating the experimentally measured fragment distributions.
