Previous projects.The thread that ties together all of the projects of the Burgmayer research group is the class of organic molecule known as pteridines. The group has been studying the interactions between pterins/pteridines and transition metals, where these studies have included syntheses, reactivities and spectroscopic characterizations. The goal of these studies is a description of the function of metalloenzymes which use pterin cofactors as assistants in catalyzing the biological reactions. Our foray into transition metal-pterin chemistry began with model studies for the molybdenum enzymes then branched to develop systems for the aromatic amino acid hydroxylases, of which the best known is phenylalanine hydroxylase which utilizes iron and biopterin. The published work from the Burgmayer labs has primarily concerned transition metal coordination to pterins and pteridines and the associated oxidation/reduction reactions between the metals and pterins/pteridines. Our group has accomplished a good portion of the studies in this area and these are described in a review recently published in the series Structure and Bonding. The Burgmayer research group is one of a very few that attempt to conduct research in metal-pterin chemistry. Pterin chemistry is notoriously difficult for primarily solubility reasons and long preparative routes in some cases. Most recently three papers entitled "Molybdenum-Pterin Chemistry" appeared in Inorganic Chemistry. The first paper describes the structure and the unusual 5-electron redox reaction of a molybdenum dithiocarbamate complex of trihydropterin. The second paper provides crystallographic for a Mo-alloxazine complex that had been disputed in the literature twenty years ago. The third paper is the culmination of studies begun independently in my labs and in those of Dr. Berthold Fischer. Each of us has investigated the reactions of di-oxo-molybdenum(VI) complexes with tetrahydropterins with different interpretations. Through the use of X-ray photoelectron spectroscopy experiments, results were obtained confirming our current view that the complex fromed from Mo(+6) and tetrahydropterin is most like a Mo(+5)-trihydropterin in its electronic structure. Earlier papers investigated the conditions for bidentate chelation of oxidized pterins/pteridines to first row metals. A second research area that has been developed over the last decade in my labs concerns the synthesis of molybdenum dithiolene compounds. The goal of this project is to ultimately prepare a model complex whose structure is nearly identical to that of the molybdenum site in the dimethylsulfoxide reductase (DMSOR) family of enzymes. Further information about this project is found at Current Research.