Coordination and Bioinorganic Chemistry with Sulfur Ligands

University Of Delaware, Newark DE

Investigators

Abstract

Dr. Charles G. Riordan, Chemistry Department, University of Delaware is supported by the Inorganic, Bioinorganic, and Organometallic Program to develop develop homogeneous, coordination complexes of nickel that activate dioxygen under mild conditions. A series of monovalent nickel complexes supported by poly(thioether)borato ligands will be allowed to react with O2 to generate thermally-sensitive, reduced oxygen intermediates. The molecular and electronic structure of these intermediates will be studied using low temperature spectroscopic techniques including UV-visible, resonance Raman, X-ray absorption and X-ray diffraction analyses. These results will be interpreted using density functional theory to define the reaction landscape of the nickel-oxygen species to establish geometric- and electronic-structure function correlations. Concomitant experiments will explore nickel-based activation of relatedsubstrates, e.g. elemental sulfur, phosphorous and diazenes, RN=NR. Selective oxidation of organic substrates generally increases their utility in the chemical and pharmaceutical arenas. Oxidations employing O2 represent attractive and environmentally responsible approaches. The approach is inspired by an appreciation of the activity and chemical selectivity with which metalloproteins utilize dioxygen to synthesize new molecules. Outcomes from the studies will have broad implications to industrial and biological oxidation processes. The breadth of the research experience will provide excellent intellectual and technical training for students in organic and inorganic synthesis, physical measurements and kinetic and mechanistic aspects of inorganic chemistry. The experience will prepare students for careers in either industry or academia.