The Experimental Physical Chemistry Program supports John S. Muenter of the University of Rochester as he continues his investigations into the structure and dynamics of highly vibrationally excited states of small and medium-sized molecules. He will populate the excited state using Ti:sapphire laser excitation, then probe the prepared state in the radiofrequency, microwave or infrared region using molecular beam electric resonance spectroscopy. By examining a variety of molecules with varying densities of states, he can characterize the high energy vibrational state as intramolecular vibrational relaxation begins to occur. The goals are to determine (a) the contributions of various vibrational modes, including dark states, to the excited state wavefunctions, and the (b) equilibrium structure and (c) dipole moment of the excited state. This knowledge of high energy molecular states will provide important foundation material for a wide variety of kinetics and dynamics experiments. High energy states serve as precursors to a broad range of chemical reactions. These experiments are designed to provide information to maximize the productivity of many kinetics and dynamics experiments. In addition, data obtained here will provide exacting tests of theoretical potential energy surfaces, and the knowledge of high energy states gained here will allow the construction of more accurate potential surfaces in the future. Finally, the techniques developed for this work can be applied to many other experiments in physical chemistry.
