title: Influence of the Dithiolate Bridge on the Oxidative Processes of Diiron Models Related to the Active Site of [FeFe] Hydrogenases.
abstract: Electrochemical studies of [Fe2(CO)4(κ2-dmpe)(μ-dithiolate)] (dithiolate=adtBn, pdt) and density functional theory (DFT) calculations reveal the striking influence of an amine functionality in the dithiolate bridge on their oxidative properties. [Fe2(CO)4(κ2-dmpe)(μ-adtBn)] (1) undergoes two one-electron oxidation steps, with the first being partially reversible and the second irreversible. When the adtBnbridge is replaced with pdt, a shift of 60 mV towards more positive potentials is observed for the first oxidation whereas 290 mV separate the oxidation potentials of the two cations. Under CO, oxidation of azadithiolate compound 1 occurs according to an ECE process whereas an EC mechanism takes place for the propanedithiolate species 2. The dication species [1-CO]2+resulting from the two-electron oxidation of 1 has been spectroscopically and structurally characterized. The molecular details underlying the reactivity of oxidized species have been explored by DFT calculations. The differences in the behaviors of 1 and 2 are mainly due to the presence, or not, of favored interactions between the dithiolate bridge and the diiron site depending on the redox states, FeIFeIIor FeIIFeII, of the complexes.
authors.affiliation: Department of Biotechnology and Bioscience, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Arrigoni
authors.affiliation: UMR CNRS 6521 Chimie, Electrochimie Moléculaires et Chimie Analytique, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238, Brest-Cedex 3, France.
authors.forename: Salma
authors.initials: S
authors.lastname: Mohamed Bouh
authors.affiliation: Department of Biotechnology and Bioscience, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: De Gioia
authors.affiliation: UMR CNRS 6521 Chimie, Electrochimie Moléculaires et Chimie Analytique, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238, Brest-Cedex 3, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Elleouet
authors.affiliation: UMR CNRS 6521 Chimie, Electrochimie Moléculaires et Chimie Analytique, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238, Brest-Cedex 3, France.
authors.forename: François Y
authors.initials: FY
authors.lastname: Pétillon
authors.affiliation: UMR CNRS 6521 Chimie, Electrochimie Moléculaires et Chimie Analytique, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238, Brest-Cedex 3, France.
authors.forename: Philippe
authors.identifier: http://orcid.org/0000-0001-8161-7878
authors.initials: P
authors.lastname: Schollhammer
authors.affiliation: Department of Biotechnology and Bioscience, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zampella
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry; D020134:Catalytic Domain; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D055664:Electrochemical Techniques; D005290:Ferric Compounds / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D011407:Propane / Q000031:analogs & derivatives / Q000737:chemistry; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D056831:Coordination Complexes; D005290:Ferric Compounds; D007506:Iron-Sulfur Proteins; D013438:Sulfhydryl Compounds; C522648:propanedithiolate; D002248:Carbon Monoxide; C118830:iron hydrogenase; D006864:Hydrogenase; D011407:Propane
keywords: bridging ligands; density functional theory; electrochemistry; enzyme models; oxidation