Photoinitiated Reactions in Ultracold Helium Clusters

University Of Southern California, Los Angeles CA

Investigators

Abstract

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Wittig will investigate photoinitiated processes that involve polyatomic molecules embedded in helium droplets, He(n). This work stands at the forefront of contemporary physical chemistry and its goal is to obtain quantitative understanding of relaxation and reactive processes that take place in an exceptionally well-characterized bath of liquid helium. Broad knowledge developed for gas phase photochemistry will be used in the modeling of processes in the condensed medium. New chemical systems, almost unperturbed by surroundings, but difficult in being formed and studied in jet expansions, will be investigated. This research deals with the properties of molecules trapped in and on the surfaces of ultracold droplets of liquid helium. Such embedded, or attached, molecules can rotate freely, but with a rotational parameter that is different from the one that characterizes the rotation of molecules in a dilute gas. Molecular systems that are very difficult to prepare by conventional methods due to their high reactivity can thereby be made accessible to study. Such highly reactive species play an important role in chemical reactions and the proposed research will provide information not otherwise available or very difficult to obtain. The research will be conducted with the assistance of graduate and undergraduate students, and postdoctoral research associates. These collaborators will acquire skills and knowledge in a forefront area of physical chemistry that prepares them for advanced studies or employment in industry, government research laboratories, or academia.