title: Reactivity of the Excited States of the H-Cluster of FeFe Hydrogenases.
abstract: FeFe hydrogenases catalyze H2oxidation and formation at an inorganic active site (the "H-cluster"), which consists of a [Fe2(CO)3(CN)2(dithiomethylamine)] subcluster covalently attached to a Fe4S4subcluster. This active site is photosensitive: visible light has been shown to induce the release of exogenous CO (a reversible inhibitor of the enzyme), shuffle the intrinsic CO ligands, and even destroy the H-cluster. These reactions must be understood because they may negatively impact the use of hydrogenase for the photoproduction of H2. Here, we explore in great detail the reactivity of the excited states of the H-cluster under catalytic conditions by examining, both experimentally and using TDDFT calculations, the simplest photochemical reaction: the binding and release of exogenous CO. A simple dyad model can be used to predict which excitations are active. This strategy could be used for probing other aspects of the photoreactivity of the H-cluster.
authors.affiliation: Aix Marseille Univ., CNRS, BIP UMR 7281 , Marseille, France.|Department of Biotechnologies and Biosciences, University of Milano-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Sensi
authors.affiliation: Aix Marseille Univ., CNRS, BIP UMR 7281 , Marseille, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Baffert
authors.affiliation: Department of Earth and Environmental Sciences, Milano-Bicocca University , Piazza della Scienza 1, 20126 Milan, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Greco
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6 , 11 Place Marcelin Berthelot, Paris 75231 Cedex 05, France.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Caserta
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504 , avenue de Rangueil, 31077 Toulouse, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Gauquelin
authors.affiliation: Institut de Biologie et de Technologies de Saclay IBITECS, SB2SM/Institut de Biologie Intégrative de la Cellule I2BC, UMR 9198, CEA, CNRS, Université Paris Sud , F-91191 Gif sur Yvette, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Saujet
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6 , 11 Place Marcelin Berthelot, Paris 75231 Cedex 05, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.affiliation: Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CNRS, CEA , 17 rue des Martyrs, 38054 Grenoble, France.
authors.forename: Souvik
authors.initials: S
authors.lastname: Roy
authors.affiliation: Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CNRS, CEA , 17 rue des Martyrs, 38054 Grenoble, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Artero
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504 , avenue de Rangueil, 31077 Toulouse, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Soucaille
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504 , avenue de Rangueil, 31077 Toulouse, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Meynial-Salles
authors.affiliation: Institut de Biologie et de Technologies de Saclay IBITECS, SB2SM/Institut de Biologie Intégrative de la Cellule I2BC, UMR 9198, CEA, CNRS, Université Paris Sud , F-91191 Gif sur Yvette, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Bottin
authors.affiliation: Department of Biotechnologies and Biosciences, University of Milano-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: de Gioia
authors.affiliation: Aix Marseille Univ., CNRS, BIP UMR 7281 , Marseille, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Fourmond
authors.affiliation: Aix Marseille Univ., CNRS, BIP UMR 7281 , Marseille, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Léger
authors.affiliation: Department of Biotechnologies and Biosciences, University of Milano-Bicocca , Piazza della Scienza 2, 20126 Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bertini