title: Oxidized and reduced [2Fe-2S] clusters from an iron(I) synthon.
abstract: Synthetic [2Fe-2S] clusters are often used to elucidate ligand effects on the reduction potentials and spectroscopy of natural electron-transfer sites, which can have anionic Cys ligands or neutral His ligands. Current synthetic routes to [2Fe-2S] clusters are limited in their feasibility with a range of supporting ligands. Here, we report a new synthetic route to synthetic [2Fe-2S] clusters, through oxidation of an iron(I) source with elemental sulfur. This method yields a neutral diketiminate-supported [2Fe-2S] cluster in the diiron(III)-oxidized form. The oxidized [2Fe-2S] cluster can be reduced to a mixed valent iron(II)-iron(III) compound. Both the diferric and reduced mixed valent clusters are characterized using X-ray crystallography, Mössbauer spectroscopy, EPR spectroscopy and cyclic voltammetry. The reduced compound is particularly interesting because its X-ray crystal structure shows a difference in Fe-S bond lengths to one of the iron atoms, consistent with valence localization. The valence localization is also evident from Mössbauer spectroscopy.
authors.affiliation: Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520, USA.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Reesbeck
authors.forename: Meghan M
authors.initials: MM
authors.lastname: Rodriguez
authors.forename: William W
authors.initials: WW
authors.lastname: Brennessel
authors.forename: Brandon Q
authors.initials: BQ
authors.lastname: Mercado
authors.forename: David
authors.initials: D
authors.lastname: Vinyard
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Holland
mesh_terms: D058085:Iron Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010084:Oxidation-Reduction
chemical_list: D058085:Iron Compounds; D007506:Iron-Sulfur Proteins