Lisa McElwee-White of the Chemistry Department of Stanford University is supported by the Inorganic, Bioinorganic, and Organometallic Program for continued investigation of the reactions of photochemically-generated organometallic radical cations. Metal carbyne complexes of molybdenum and tungsten, which also contain cyclopentadiene, carbonyl and phosphine ligands, are the starting materials. Depending on reaction condition, the radicals produced undergo ligand substitution or carbyne ligand rearrangement reactions. The rearrangement reactions produce organic products stereospecifically. In this study, the mechanism of the rearrangement reaction will be studied using spectroscopic and isotopic labelling experiments,and a variety of carbyne ligands will be tested. The goal of the research is to develop new methods of organic synthesis, especially for desirable stereospecific products. %%% In this fundamental research project, light will be used to induce the production of organic molecules of specific symmetries. The reactant molecule, which contains a carbon-carbon triple bond, is originally bound to a metal complex. Upon irradiation, it rearranges in a specific way and is released to form the product. The project will develop new methods of synthesis for various organic products.