In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Patrick Vacarro of Yale University will exploit a newly developed high-resolution laser spectroscopic method to explore the ground state potential energy hypersurfaces for a number of polyatomic systems, including both stable and unstable species. This degenerate four-wave mixing (DFWM) technique relies on the simultaneous creation and detection of transient spatial gratings within a gas-phase ensemble of molecules and offers several advantages over traditional spectroscopies. The current project will furnish information on the structure and dynamics of molecules with very highly excited vibration-rotation levels which can lead to an enhanced understanding of the intra- and intermolecular processes involved with highly excited polyatomic species, such as predissociation and ground-state isomerism. %%% Polyatomic molecules which contain large amounts of energy in vibrating bonds have an important impact on a wide variety of phenomena, such as combustion diagnosis and atmospheric modelling. This study proposes to user laser-based techniques to study small transient polyatomic molecules possessing considerable vibrational excitation to determine their behavior as a result of the excess energy.
