Dr. Laurie J. Butler is supported by a grant from the Experimental Physical Chemistry Program to study the time evolution of molecular dissociation processes from electronically excited molecules. These measurements will allow for an enhanced detailed understanding of how molecules decompose and form various sub-molecular moieties or of how chemical species react with other systems. The initial experiments use polarized emission spectroscopy, which measures the wavelength and polarization of the photons emitted during dissociation, to probe the change in the nuclear dynamics induced by forces at a conical intersecton along the dissociative pathway. Professor Butler focuses on determining the change in the dissociation dynamics and the branching between energetically allowed fragmentation products induced by 1) the presence of a conical intersection along the dissociation pathway, 2) the excitation of a selected vibrationally activated molecule to the electronically dissociative state, allowing access to the excited potential surface beyond the Franck-Condon region, and 3) the change in the nonadiabatic coupling between two dissociative electronic states when a vibrationally excited molecule is promoted to the dissociative surface.
