Professor Barbara is supported by the Experimental Physical Chemistry Program in an experimental investigation in "real time" of the dynamics of motion along the reaction coordinate for chemical reactions in solution. Systems are chosen that are especially amenable to theoretical interpretation and that allow fundamental insight into liquid phase reactions. The research directly impacts on the understanding of metal-metal charge transfer reactions and low temperature electron transfer mechanisms relevant to photosynthesis. Professor Barbara is developing various novel pump-probe techniques for ultrafast spectroscopy and applying them to electron transfer reactions in both ground and excited states. Resonant electronic excitation by an ultrashort laser pulse is used to prepare a reaction system in a distribution of geometries near the transition state. The subsequent evolution of the system along the reaction coordinate is then monitored by femtosecond spectroscopy. Various theoretical models and simulations are used to aid in interpreting the experimental results.
