The overall goal of this project is to devise synthetic metal complexes that will promote the incorporation of both oxygen atoms of dioxygen into selected organic substrates. The prototype metal complexes would have considerable utility for synthesis of organic compounds, and would be of potential value for amelioration of environmental contamination by aromatic compounds and chlorinated hydrocarbons. The rationale for attempted development of this new oxidation route is found in the known dioxygenase enzymatic chemistry of microbes that are responsible for oxidation and de-aromatization of aromatic compounds to the cis- dihydrodiol form. This enzymatic system is also effective for oxidative dehalogenation of the priority pollutant trichloroethylene. The microbial dioxygenase enzymes utilize molecular oxygen, NADH, and a putative monomeric iron(II) active site. No model compound work has been performed on this class of enzymes, and the aryl dioxygenation reaction is unprecedented in organic chemistry. Efforts will be made to emulate the chemistry by preparation and activation of peroxide and related O-O ligands on iron and manganese porphyrins and other iron chelated complexes. Systematic reactivity studies will be carried out in order to provide strategy for optimization of the reactivity, efficiency, and stability of the prototype metal complexes.