1. Triggering the generation of an iron(IV)-oxo compound and its reactivity toward sulfides by RuII photocatalysis
- Author
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Anna Company, Gerard Sabenya, María González-Béjar, Laura Gómez, Martin Clémancey, Geneviève Blondin, Andrew J. Jasniewski, Mayank Puri, Wesley R. Browne, Jean-Marc Latour, Lawrence Que, Miquel Costas, Julia Pérez-Prieto, Julio Lloret-Fillol, Ministerio de Economía y Competitividad (Espanya), Ministerio de Ciencia e Innovación (Espanya), European Research Council, Generalitat de Catalunya. Agència de Gestió d'Ajuts Universitaris i de Recerca, Departament de Química, Universitat de Girona (UdG), Instituto de Ciencia Molecular (ICMol), Universitat de València (UV), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Stratingh Institute for Chemistry, University of Groningen [Groningen], and Synthetic Organic Chemistry
- Subjects
Sulfide ,Fotocatàlisi ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,Chemical reaction ,Article ,Catalysis ,Reaccions químiques ,Reaction rate ,Colloid and Surface Chemistry ,Sofre -- Compostos ,Chemical reactions ,Sulphur compounds ,Organic chemistry ,WATER ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Photosensitizer ,Reactivity (chemistry) ,Photocatalysis ,chemistry.chemical_classification ,OXYGENATION REACTIONS ,010405 organic chemistry ,Chemistry ,General Chemistry ,Electron acceptor ,STATE ,0104 chemical sciences ,ELECTRON-TRANSFER PROPERTIES ,C-H OXIDATION ,SPIN FE(IV) COMPLEX ,IRON-OXO COMPLEXES ,LIGAND ,TAURINE/ALPHA-KETOGLUTARATE DIOXYGENASE ,NONHEME OXOIRON(IV) COMPLEXES - Abstract
The preparation of [FeIV(O)(MePy2tacn)]2+ (2, MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane) by reaction of [FeII(MePy2tacn)(solvent)]2+ (1) and PhIO in CH3CN and its full characterization are described. This compound can also be prepared photochemically from its iron(II) precursor by irradiation at 447 nm in the presence of catalytic amounts of [Ru II(bpy)3]2+ as photosensitizer and a sacrificial electron acceptor (Na2S2O8). Remarkably, the rate of the reaction of the photochemically prepared compound 2 toward sulfides increases 150-fold under irradiation, and 2 is partially regenerated after the sulfide has been consumed; hence, the process can be repeated several times. The origin of this rate enhancement has been established by studying the reaction of chemically generated compound 2 with sulfides under different conditions, which demonstrated that both light and [Ru II(bpy)3]2+ are necessary for the observed increase in the reaction rate. A combination of nanosecond time-resolved absorption spectroscopy with laser pulse excitation and other mechanistic studies has led to the conclusion that an electron transfer mechanism is the most plausible explanation for the observed rate enhancement. According to this mechanism, the in-situ-generated [RuIII(bpy)3] 3+ oxidizes the sulfide to form the corresponding radical cation, which is eventually oxidized by 2 to the corresponding sulfoxide We acknowledge the European Commission for projects FP7-PEOPLE-2011-CIG-303522 (A.C.), FP7-PEOPLE-2010-ERG-268445 (J.L.-F.), FP7-PEOPLE-CIG-303522 (M.G.B.), and ERC-009StG-239910 (MC.); the Spanish Ministry of Science for Projects CTQ2012-37420-C02-01/BQU (MC.), CSD2010-00065 (MC.), and CTQ2011-27758 (J.P.P.); Generalitat de Catalunya for an ICREA Academia Award and Project 2009-SGR637 (M.C.); and Generalitat Valenciana for Project ACOMP/2013/008 (J.P.P.). The Spanish Ministry of Science is acknowledged for a Ramon y Cajal contract to A.C. and J.L.-F. J.M.L. acknowledges the support, in part, of Labex ARCANE (ANR-11-LABX-0003-01). The work at the University of Minnesota was supported by the US National Science Foundation (Grant CHE1058248 to L.Q) and the Dr. Venkateswarlu Pothapragada and Family Fellowship (to M.P.). XAS data were collected at beamline 9-3 of the Stanford Synchrotron Radiation Lightsource supported by the US-NIH and US-DOE. We thank Catexel for a generous gift of tritosyl-1,4,7-triazacyclononane
- Published
- 2014
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