Dr. Hai-Lung Dai is supported by a grant from The Experimental Physical Chemistry Program to study intermolecular potential functions for van der Waals complexes using molecular beam and laser spectroscopic methodology. Dr. Dai is using stimulated emission pumping (SEP) on van der Waals complexes to study the interaction potential between molecules and the dynamics of reaction and energy transfer of vibrationally excited molecules. Model intermolecular potentials are being developed and tested with the van der Waals mode frequencies and the complex structures which are experimentally observed. Vibrational predissociation of the complexes is being examined as a function of both the vibrational energy and the vibrational mode. Stimulated emission pumping will also be used to prepare a large quantity of complexes in a selectively excited vibrational level. The product vibrational state distribution after predissociation will be probed. Correlation between the excited level and the product states may reveal the effect of attractive forces in vibrational energy transfer and the propensities of low energy collision-induced V-V transfer.
