In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Alec Wodtke will investigate the role of bimolecular transition states in vibrational energy transfer in highly vibrationally excited molecules. The vibrational dependence of intermolecular energy transfer will be studied over a wide range of energy above and below the chemical transition states for endothermic chemical reactions in a variety of different systems. In these experiments the excited species will be created using Stimulated Emission Pumping (SEP). The main system for study is the diatomic molecule NO, but experiments will also be performed on the HCN - HNC isomerization, leading to some of the first experimental information on a molecule larger than a diatomic. %%% In this project Wodtke will use laser techniques to put large amounts of energy into vibrational motions of the chemical bonds of several molecules whose reactions are important for understanding atmospheric chemistry. Such excited molecules can undergo chemical reactions which unexcited species will not. This effort is relevant to understanding global warming, ozone hole formation, and the creation and remote sensing of nitric oxide, a known catalyzer of ozone destruction.