title: Combining acid-base, redox and substrate binding functionalities to give a complete model for the [FeFe]-hydrogenase.
abstract: Some enzymes function by coupling substrate turnover with electron transfer from a redox cofactor such as ferredoxin. In the [FeFe]-hydrogenases, nature's fastest catalysts for the production and oxidation of H(2), the one-electron redox by a ferredoxin complements the one-electron redox by the diiron active site. In this Article, we replicate the function of the ferredoxins with the redox-active ligand Cp*Fe(C(5)Me(4)CH(2)PEt(2)) (FcP*). FcP* oxidizes at mild potentials, in contrast to most ferrocene-based ligands, which suggests that it might be a useful mimic of ferredoxin cofactors. The specific model is Fe(2)[(SCH(2))(2)NBn](CO)(3)(FcP*)(dppv) (1), which contains the three functional components of the active site: a reactive diiron centre, an amine as a proton relay and, for the first time, a one-electron redox module. By virtue of the synthetic redox cofactor, [1](2+) exhibits unique reactivity towards hydrogen and CO. In the presence of excess oxidant and base, H(2) oxidation by [1](2+) is catalytic.
authors.affiliation: School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Camara
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Rauchfuss
mesh_terms: D001665:Binding Sites; D020134:Catalytic Domain; D005288:Ferredoxins / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry*; D008954:Models, Biological; D010084:Oxidation-Reduction; D013379:Substrate Specificity
chemical_list: D005288:Ferredoxins; D006864:Hydrogenase