With this award, the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research by Dr. Steven P. Nolan of the Chemistry Department, University of New Orleans, for studies to determine bond strengths in organometallic compounds. Metal-ligand bond enthalpies will be determined primarily for carbonyl and phosphine bonds for compounds involved in homogeneous catalysis. Novel mono- and bi-dentate phosphines and phosphites of iron and ruthenium, and ruthenium and rhodium carbonyls will be studied. In addition some metal-carbon, metal-hydrogen, and metal-silicon bond enthalpies will be investigated. Thermodynamic data provides a quantitative basis for understanding reactivity in reactions, including catalytic reactions. The feasibility of new reactions can be predicted and design of new catalysts can be optimized. The available thermodynamic data on organometallic compounds is limited. This research will provide basic information on the enthalpy for breaking metal-carbon and metal-phosphorus bonds in compounds related to those found in important industrial catalysts.