Spectroscopy and Dynamics of Radicals and Clusters by Tunable-Laser Dissociative Photodetachment

University Of California-San Diego, La Jolla CA

Investigators

Abstract

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Continetti will use a tunable laser to study the dissociative photodetachment (DPD) and photodetachment dynamics of radicals and clusters. In these experiments, photoelectron-photofragment coincidence (PPC) spectroscopy combined with tunable laser photodetachment/threshold photoelectron spectroscopy will be used to carry out high-resolution studies on organic radicals as well as the wavelength-dependent DPD dynamics of cluster anions. These studies will focus on the spectroscopy and dissociation dynamics of alkoxy radicals important in atmospheric chemistry. Electronic structure and unimolecular dissociation calculations will be carried out to aid in the interpretation of the observed energetics and dissociation dynamics. Studying the wavelength dependence of the photodetachment dynamics of cluster anions and other transient species provides important information on the electronic structure of these systems and problems in electron-molecule interactions that are at the forefront of modern electronic structure theory. This grant supports the application of spectroscopic techniques to the study of short-lived, reactive molecules important in atmospheric and combustion chemistry. An important focus of the research will be on a class of molecules known as alkoxy radicals. They play an important role in aspects of urban air pollution chemistry, but in spite of their importance, basic information about their stability and reactions are not known. This research project will help to fill in these gaps in our understanding of these important species, providing a solid empirical foundation for efforts to improve the modeling of atmospheric pollution phenomena. Graduate and undergraduate students will participate in experiments involving state-of-the-art lasers and detection techniques, computer modeling and prediction of chemical properties. They will thereby receive training in forefront methods of chemical research in preparation for advanced studies or entry into the scientific/technical workforce.