This award by the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Carl J. Carrano at San Diego State University to study a family of ligands that allows for the systematic variance of donor atom, charge, steric bulk, hydrogen-bonding and other factors that can have an important effect on metal-catalyzed biotransformations. Ligand effects on oxygen atom transfer reactions between acceptors such as organophosphines and models for molybdoenzymes will be systematically studied. New sulfur-rich model complexes to more closely mimic enzyme active sites will be prepared. Pentaacoordinate complexes of iron will be prepared as models for several non-heme iron oxygenase enzymes in order to determine the effects of the donor atom set, charge, and hydrogen bonding and other factors that control oxygenation versus oxidation. Pseudotetrahedral iron complexes will be synthesized and studied as models for peptide deformylases and compared with analogous complexes of Co(II), Ni(II) and Zn(II) in order to determine why Fe(II) rather than Zn(II) is employed by nature in these unique hydrolytic enzymes.
Relatively small complexes of metal ions will be prepared that simulate the structure and function of metal active sites in enzymes. Studying these complexes will help to elucidate the fundamental nature of the function of the metal ions in a number of important enzymes.
