Professor Miguel Garcia-Garibay, of the Department of Chemistry and Biochemistry at the University of California at Los Angeles, is supported by the Organic Dynamics Program for his studies of the ground state and photochemical reactivity of triplet carbenes in the crystalline solid state. Carbenes are generated photochemically by extrusion of molecular nitrogen within crystals of their arylalkyldiazo precursors. Specific substrates are chosen to allow the investigation of intramolecular 1,2-hydride and 1,2-phenyl migrations as well as hydrogen abstractions. Professor Garcia-Garibay examines the correlation between solid-state structural aspects of the precursors and reaction trajectories of the resultant carbenes, studying both the energetics of the reaction processes and their potential application in the synthesis of organic compounds through stereoselective solid-state carbene rearrangements. Although the chemistry of carbon compounds, forming the basis of organic chemistry, is dominated by the preference of this element to form bonds to four other elements, compounds in which carbon is bonded to only two other elements are also known. These so-called carbenes, which arise as intermediates in a number of important chemical transformations, display a variety of intriguing properties, including high reactivity and a propensity to undergo molecular rearrangements. Professor Garcia-Garibay harnesses the chemistry of these reactive carbenes by generating them within crystalline hosts, thereby permitting the physical and chemical examination of their structures and chemical reactions. These studies address both fundamental issues regarding the chemistry of carbenes and practical issues regarding the use of carbenes in the controlled synthesis of important organic compounds.
