Femtosecond Studies of Chemical Reaction Dynamics in Liquids

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Charles Harris of the University of California, Berkeley is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for research on the kinetics (at the femto-second time scale) and the intimate mechanisms of rather complex organometallic reactions. Using femtosecond infrared spectroscopy coupled with high pressure techniques, the intimate mechanisms of a variety of complex chemical reactions will be elucidated. Special attention will be paid to the role of solvent molecules in these reactions. Initial interest will be centered on the activation by transition metal complexes of selective C-H and Si-H bond ruptures. A variety of more complex reactions, including alkyne polymerization, will also be examined. Reaction dynamics will be interpreted with the aid of stochastic dynamic simulations. Several theoretical methods, including ab initio calculations and density functional methods, will be applied to characterization of intermediates. This research is extending the time range accessible in the study of the intimate mechanisms of solution-phase inorganic reactions by several orders of magnitude. The details of reactions that are instantaneous by other measures will be brought under examination. Such heretofore inaccessible chemical changes stand at critical points in networks of reactions that are of central importance in many scientific and technological areas. Specific examples of topics where this research may have great importance include studies of the mechanisms of biological processes such as photosynthesis and respiration, and also improvement of metal-catalyzed polymerizations that are of central importance in the chemical industry.