The objective of our research is to understand, at the detailed molecular level, the mechanisms of chemical reactions relevant to catalysis, combustion, and atmospheric chemistry. Reactive species such as molecular free radicals are prepared in molecular beams using a variety of novel laser-based methods. Photoinduced unimolecular reactions and bimolecular reactions with stable molecules are studied in crossed molecular beams. Reactions are induced by single collisions between molecules in the gas phase in crossed molecular beams, at liquid interfaces, or induced by absorption of a photon. Neutral products from these reactions are ionized using “soft” single photon ionization using high-intensity vacuum ultraviolet (VUV; λ < 180 nm) and extreme ultraviolet (XUV; λ < 110 nm) light produced by frequency upconversion using novel tabletop laser-based light sources. The ions are then detected using various highly sensitive mass spectrometric techniques. For reactions producing atomic products such as H, D or O, Rydberg tagging time-of-flight spectroscopy is employed. Most of the information is derived from measurements of product angular and velocity distributions as a function of collision energy and reactant internal energy.
Our research is currently supported by the National Science Foundation, and the U.S. Department of Energy. In the past, we have also been supported by the Office of Naval Research, ACS Petroleum Research Fund, and the Alfred P. Sloan Foundation. We are grateful to these funding agencies for support of our research efforts.