The X-ray crystal structure determination of the enzyme nitrogenase answered many questions but left the bioinorganic chemical field with one of its most challenging synthetic targets ever. The elucidation of the iron-molybdenum cofactor (FeMoco) structure of nitrogenase allowed a more definitive look at how Nature managed to combine 8 transition metal atoms and 9 sulfur atoms into an active-site core with such an unusual structure which functions as one of her most biologically important catalysts. This research endeavors to use the synthetic analogue approach to produce a precise synthetic structural model of the V analogue of FeMoco, FeVco, and explore in depth its chemistry and reactivity as it relates to the nitrogenase enzyme. To this end we will examine a number of synthetic routes including the self assembly approach as well as reaction of simple analogue building blocks to form larger clusters. We plan to coordinate trigonally symmetric tridentate ligands, such as tris(pyrazolyl)methanesulfonate (Tpms), to the V site in VFe3S4 cubes to use as building blocks in this approach. Attempts will be made to form sulfide-bridged double cubanes containing these clusters as well as a cluster with the topology of FeV cofactor. We plan to isolate pure compounds with the cofactor topology through these routes and subsequently study their reactive properties.
