Author: "Geneviève Blondin" - Searchworks@Jio Institute Digital Library Search Results

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93 results on '"Geneviève Blondin"'

1. ISCA1 is essential for mitochondrial Fe4S4 biogenesis in vivo

Author: Lena Kristina Beilschmidt, Sandrine Ollagnier de Choudens, Marjorie Fournier, Ioannis Sanakis, Marc-André Hograindleur, Martin Clémancey, Geneviève Blondin, Stéphane Schmucker, Aurélie Eisenmann, Amélie Weiss, Pascale Koebel, Nadia Messaddeq, Hélène Puccio, and Alain Martelli
Subjects: Science
Abstract: The mitochondrial proteins ISCA1 and ISCA2 form a complex that is involved in the biogenesis of Fe–S clusters. Here the authors report that ISCA1 and ISCA2 interact differently with proteins of the Fe–S machinery and that under certain conditions, ISCA2 seems dispensable for Fe–S biogenesis.
Published: 2017
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2. In Cellulo Mössbauer and EPR Studies Bring New Evidence to the Long‐Standing Debate on Iron–Sulfur Cluster Binding in Human Anamorsin

Author: Geneviève Blondin, Martin Clémancey, Lucia Banci, Francesca Camponeschi, Simone Ciofi-Baffoni, Sara Matteucci, University of Florence, Department of Chemistry and Magnetic Resonance Center (CERM), Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (CIRMMP), Università degli Studi di Siena = University of Siena (UNISI)-Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI)-University of Bologna-Partenaires INRAE, Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Department of Chemistry, University of Florence, ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), Università degli Studi di Firenze = University of Florence (UniFI), and Università degli Studi di Siena = University of Siena (UNISI)-Università degli Studi di Firenze = University of Florence (UniFI)-University of Bologna/Università di Bologna-Partenaires INRAE
Subjects: Iron-Sulfur Proteins, anamorsin, Protein family, Stereochemistry, metalloproteins, Iron–sulfur cluster, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, 010402 general chemistry, 01 natural sciences, Catalysis, law.invention, 03 medical and health sciences, Spectroscopy, Mossbauer, chemistry.chemical_compound, in cellulo EPR spectroscopy, law, Mössbauer spectroscopy, Iron-sulfur cluster binding, Cluster (physics), Metalloprotein, Humans, in cellulo Mcssbauer spectroscopy, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Electron paramagnetic resonance, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, 010405 organic chemistry, Communication, Electron Spin Resonance Spectroscopy, Intracellular Signaling Peptides and Proteins, General Medicine, General Chemistry, Communications, iron-sulfur clusters, 0104 chemical sciences, chemistry, Iron–Sulfur Clusters, in cellulo Mössbauer spectroscopy, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Biogenesis, Protein Binding
Abstract: Human anamorsin is an iron–sulfur (Fe–S)‐cluster‐binding protein acting as an electron donor in the early steps of cytosolic iron–sulfur protein biogenesis. Human anamorsin belongs to the eukaryotic CIAPIN1 protein family and contains two highly conserved cysteine‐rich motifs, each binding an Fe–S cluster. In vitro works by various groups have provided rather controversial results for the type of Fe–S clusters bound to the CIAPIN1 proteins. In order to unravel the knot on this topic, we used an in cellulo approach combining Mössbauer and EPR spectroscopies to characterize the iron–sulfur‐cluster‐bound form of human anamorsin. We found that the protein binds two [2Fe–2S] clusters at both its cysteine‐rich motifs., A combined in cellulo Mössbauer‐ and EPR‐based approach is applied to address controversial aspects of Fe–S cluster‐binding properties of human anamorsin, a protein involved in the biogenesis of cytosolic [4Fe–4S] cluster‐binding proteins. We show that human anamorsin binds two [2Fe–2S] clusters in‐cell in two highly conserved cysteine‐rich motifs typical of the eukaryotic CIAPIN1 protein family, with different electron‐spin‐relaxation properties.
Published: 2021
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3. A multidisciplinary analysis of the as-isolated Escherichia coli SufBC2D complex reveals the presence of two new iron-sulfur clusters

Author: Giulia Veronesi, Julien Pérard, Martin Clémancey, Catherine Gerez, Yohann Duverger, Isabelle Kieffer, Frédéric Barras, Serge Gambarelli, Geneviève Blondin, and Sandrine Ollagnier de Choudens
Abstract: Iron-sulfur (Fe-S) clusters are essential inorganic cofactors dedicated to a wide range of biological functions including electron transfer and catalysis. Specialized multi-protein machineries present in all types of organisms support their biosynthesis. These machineries encompass a scaffold protein on which Fe-S clusters are assembled before being transferred to cellular targets. Here, we describe the first characterization of the native Fe-S cluster of the anaerobically purified SufBC2D scaffold from Escherichia coli by XAS, Mössbauer, UV-visible absorption and EPR spectroscopy. Interestingly, we propose that SufBC2D harbors two types of Fe-S cluster, a [2Fe-2S] cluster with an unprecedented usual coordination and a previously unreported [3Fe-3S] cluster. These data combined with mutagenesis and biochemistry allow to propose ligands for these clusters. These results support the hypothesis that both SufB and SufD are involved in Fe-S cluster ligation and are discussed in the context of Fe-S cluster biogenesis where both [2Fe-2S] and [4Fe-4S] clusters need to mature cellular Fe-S protein targets.
Published: 2022
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4. Mixed Valence (μ‐Phenoxido) Fe II Fe III and Fe III Fe IV Compounds: Electron and Proton Transfers

Author: Patrick Dubourdeaux, Geneviève Blondin, Jean-Marc Latour, Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)
Subjects: Valence (chemistry), proton transfer, biology, Proton, Chemistry, Active site, Intervalence charge transfer, electron transfer, Photochemistry, Redox, Tautomer, Atomic and Molecular Physics, and Optics, Ion, tautomerism, Electron transfer, CPET, biology.protein, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, mixed-valent diiron compound
Abstract: International audience; Mixed-valence non-heme diiron centers are present at the active sites of a few enzymes and confer them interesting reactivities with the two ions acting in concert. Related (μ-phenoxido)diiron complexes have been developed as enzyme mimics. They exhibit very rich spectroscopic properties enabling independent monitoring of each individual ion, which proved useful for mechanistic studies of catalytic hydrolysis and oxidation reactions. In our studies of such complexes, we observed that these compounds give rise to a wide variety of electron transfers (intervalence charge transfer), proton transfers (tautomerism), coupled electron and proton transfers (H. abstraction and PCET). In this minireview, we present and analyze the main results illustrating the latter aspects.
Published: 2021
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5. Intercepting a transient non-hemic pyridine

Author: Nhat Tam, Vo, Christian, Herrero, Régis, Guillot, Tanya, Inceoglu, Winfried, Leibl, Martin, Clémancey, Patrick, Dubourdeaux, Geneviève, Blondin, Ally, Aukauloo, and Marie, Sircoglou
Subjects: Models, Molecular, Oxygen, Molecular Structure, Pyridines, Ferric Compounds
Abstract: In the context of bioinspired OAT catalysis, we developed a tetradentate dipyrrinpyridine ligand, a hybrid of hemic and non-hemic models. The catalytic activity of the iron(III) derivative was investigated in the presence of iodosylbenzene. Unexpectedly, MS, EPR, Mössbauer, UV-visible and FTIR spectroscopic signatures supported by DFT calculations provide convincing evidence for the involvement of a relevant Fe
Published: 2021

6. Intercepting a transient non-hemic pyridine N-oxide Fe(iii) species involved in OAT reactions

Author: Martin Clémancey, Nhat Tam Vo, Winfried Leibl, Christian Herrero, Tanya Inceoglu, Marie Sircoglou, Régis Guillot, Patrick Dubourdeaux, Geneviève Blondin, Ally Aukauloo, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), ANR-15-CE07-0021-01, LabEx CHARM3AT & ARCANE, HPC resources (GENCI-A0070810977), DataCenter@UPSud, and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Context (language use), 010402 general chemistry, 01 natural sciences, Catalysis, law.invention, chemistry.chemical_compound, law, Polymer chemistry, Mössbauer spectroscopy, Materials Chemistry, [CHIM]Chemical Sciences, Fourier transform infrared spectroscopy, Electron paramagnetic resonance, 010405 organic chemistry, Chemistry, Ligand, Metals and Alloys, Pyridine-N-oxide, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Ceramics and Composites, Derivative (chemistry)
Abstract: International audience; In the context of bioinspired OAT catalysis, we developed a tetradentate dipyrrinpyridine ligand, a hybrid of hemic and non-hemic models. The catalytic activity of the iron(iii) derivative was investigated in the presence of iodosylbenzene. Unexpectedly, MS, EPR, Mossbauer, UV-visible and FTIR spectroscopic signatures supported by DFT calculations provide convincing evidence for the involvement of a relevant Fe-III-O-N-Py active intermediate.
Published: 2021
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7. Experiments and DFT Computations Combine to Decipher Fe-Catalyzed Amidine Synthesis through Nitrene Transfer and Nitrile Insertion

Author: Colette Lebrun, Ranjan Patra, Guillaume Coin, Jacques Pécaut, Ludovic Castro, Pascale Maldivi, Patrick Dubourdeaux, Jean-Marc Latour, Pierre-Alain Bayle, Frédéric Avenier, Geneviève Blondin, Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Amity Institute of Click Chemistry Research & Studies (AICCRS), Conception d’Architectures Moléculaires et Processus Electroniques (CAMPE ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Département Interfaces pour l'énergie, la Santé et l'Environnement (DIESE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Chimie Interface Biologie pour l’Environnement, la Santé et la Toxicologie (CIBEST ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), and Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: multicomponent reaction, Nitrile, 010405 organic chemistry, nitrene transfer, Nitrene, mechanism, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA], DFT calculations, 01 natural sciences, Combinatorial chemistry, Chemical synthesis, Catalysis, 0104 chemical sciences, Amidine, chemistry.chemical_compound, chemistry, amidine synthesis
Abstract: International audience; Multicomponent reactions are attracting strong interest as they contribute to the development of more efficient synthetic chemistry. Understanding their mechanism is thus an important issue to optimize their operation. However, it is also a challenging task owing to the complexity of the succession of molecular events involved. Computational methods have recently proven to be of utmost interest to help decipher some of these processes, and the development of integrated experimental and theoretical approaches thus appears as the most powerful means to understand these mechanisms at the molecular level. A good example is given by the synthesis of amidines which are important pharmaceutical compounds. Their synthesis requires the association of three components, often an alkyne, a secondary amine, and an organic azide as the nitrene precursor. We found that an alternative way is offered by an Fe-catalyzed combination of a hydrocarbon, a nitrile, and a nitrene which gives amidines in good yields under mild conditions. The efficiency of the transformation and the paucity of mechanistic information on these reactions prompted us to thoroughly investigate its mechanism. Several mechanistic scenarios were explored using experimental techniques, including radical trap and N-15 labeling studies, combined with density-functional theory (DFT) calculations of reaction profiles. This allowed us to show that the amidination reaction involves the trapping of an intermediate substrate cation by an Fe-released acetonitrile molecule pointing to a true multicomponent reaction occurring exclusively within the cage around the metal center. Moreover, the calculated energy barriers of the individual steps explained how amidination outweighs direct amination in these reactions. The perfect consistency between DFT results and specific experiments to validate them strongly supports these mechanistic conclusions and highlights the potency of this combined approach.
Published: 2021
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8. Iron Oxidation in Escherichia coli Bacterioferritin Ferroxidase Centre, a Site Designed to React Rapidly with H2O2 but Slowly with O$_2$

Author: Martin Clémancey, Marina Lučić, Dimitri A. Svistunenko, Nick E. Le Brun, Jonathan A. R. Worrall, Geoffrey R. Moore, Michael T. Wilson, Geneviève Blondin, Jacob Pullin, Justin M. Bradley, University of Essex, Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), University of East Anglia [Norwich] (UEA), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Models, Molecular, Metalloproteins | Hot Paper, Photochemistry, medicine.disease_cause, Peroxide, 01 natural sciences, law.invention, chemistry.chemical_compound, law, Electron paramagnetic resonance, Research Articles, 0303 health sciences, biology, Mössbauer spectroscopy, Ceruloplasmin, Bacterioferritin, General Medicine, Oxidation-Reduction, Research Article, EPR spectroscopy, inorganic chemicals, Iron, Radical, Mossbauer spectroscopy, 010402 general chemistry, Catalysis, fast kinetics, 03 medical and health sciences, Bacterial Proteins, Escherichia coli, medicine, ferroxidase center, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], 030304 developmental biology, 010405 organic chemistry, fungi, Hydrogen Peroxide, General Chemistry, Cytochrome b Group, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 0104 chemical sciences, Oxygen, A-site, chemistry, Ferritins, biology.protein, rapid freeze-quenching, Stoichiometry
Abstract: Both O2 and H2O2 can oxidize iron at the ferroxidase center (FC) of Escherichia coli bacterioferritin (EcBfr) but mechanistic details of the two reactions need clarification. UV/Vis, EPR, and Mössbauer spectroscopies have been used to follow the reactions when apo‐EcBfr, pre‐loaded anaerobically with Fe2+, was exposed to O2 or H2O2. We show that O2 binds di‐Fe2+ FC reversibly, two Fe2+ ions are oxidized in concert and a H2O2 molecule is formed and released to the solution. This peroxide molecule further oxidizes another di‐Fe2+ FC, at a rate circa 1000 faster than O2, ensuring an overall 1:4 stoichiometry of iron oxidation by O2. Initially formed Fe3+ can further react with H2O2 (producing protein bound radicals) but relaxes within seconds to an H2O2‐unreactive di‐Fe3+ form. The data obtained suggest that the primary role of EcBfr in vivo may be to detoxify H2O2 rather than sequester iron., The kinetics of E. coli bacterioferritin di‐ferrous ferroxidase centre reacting with O2 and H2O2 shows that H2O2 reacts circa 1000 times faster than O2 implying that the primary in vivo role of the protein is ROS detoxification rather than iron sequestering.
Published: 2021
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9. Bioinspired symmetrical and unsymmetrical diiron complexes for selective oxidation catalysis with hydrogen peroxide

Author: Geneviève Blondin, Martin Clémancey, Jean-Pierre Mahy, Régis Guillot, Frédéric Avenier, Jean-Marc Latour, Alexandre Trehoux, Equipe de Chimie Bioorganique et Bioinorganique, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)
Subjects: chemistry.chemical_classification, Alkane, 010405 organic chemistry, Alkene, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Mass spectrometry, 01 natural sciences, Redox, 0104 chemical sciences, Catalysis, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Mössbauer spectroscopy, Polymer chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Hydrogen peroxide, Acetonitrile
Abstract: International audience; Two new symmetrical and unsymmetrical diiron(iii) complexes were synthesized and characterized by X-ray diffraction analysis, mass spectrometry, UV-visible and Mossbauer spectroscopies. They proved to be good catalysts for alkene and alkane oxidation reactions by H2O2 in acetonitrile solution, and interesting effects of both the nature and the symmetry of the complexes were observed on catalysis in the presence of water.
Published: 2020
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10. Single-Ion Magnetic Behaviour in an Iron(III) Porphyrin Complex: A Dichotomy Between High Spin and 5/2-3/2 Spin Admixture

Author: Joan Cano, Donatella Armentano, Martin Clémancey, Joshua Telser, Alexander Schnegg, J. Krzystek, Thomas Lohmiller, Geneviève Blondin, Marta Viciano-Chumillas, Mykhaylo Ozerov, Francesc Lloret, Instituto de Ciencia Molecular (ICMol), Universitat de València (UV), Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), National High Magnetic Field Laboratory (NHMFL), Florida State University [Tallahassee] (FSU), Dipartimento di Chimica e Technologie Chimiche (CTC), Università della Calabria [Arcavacata di Rende] (Unical), EPR Research Group, MPI Max-Planck-Institute for Chemical Energy Conversion CEC, EPR4Energy Joint Lab, Department Spins in Energy Conversion and Quantum Information Science, and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: porphyrinoids, 010402 general chemistry, [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA], 01 natural sciences, Molecular physics, Catalysis, law.invention, Magnetization, chemistry.chemical_compound, iron, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], law, Mössbauer spectroscopy, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Anisotropy, Electron paramagnetic resonance, Spin (physics), 010405 organic chemistry, Chemistry, Organic Chemistry, General Chemistry, Porphyrin, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Excited state, single-ion magnets, density functional calculations, magnetic properties, Ground state
Abstract: International audience; A mononuclear iron(III) porphyrin compound exhibiting unexpectedly slow magnetic relaxation, which is a characteristic of single-ion magnet behaviour, is reported. This behaviour originates from the close proximity (approximate to 550 cm(-1)) of the intermediate-spinS=3/2 excited states to the high-spinS=5/2 ground state. More quantitatively, although the ground state is mostlyS=5/2, a spin-admixture model evidences a sizable contribution (approximate to 15 %) ofS=3/2 to the ground state, which as a consequence experiences large and positive axial anisotropy (D=+19.2 cm(-1)). Frequency-domain EPR spectroscopy allowed them(S)= |+/- 1/2&RightAngleBracket;->|+/- 3/2&RightAngleBracket; transitions to be directly accessed, and thus the very large zero-field splitting in this 3d(5)system to be unambiguously measured. Other experimental results including magnetisation, Mossbauer, and field-domain EPR studies are consistent with this model, which is also supported by theoretical calculations.
Published: 2020
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11. Revisiting the identification of commercial and historical green earth pigments

Author: Agathe, Fanost, Alice, Gimat, Laurence de Viguerie, Pauline, Martinetto, Anne-Claire, Giot, Martin, Clémancey, Geneviève, Blondin, Fabrice, Gaslain, Glanville, Helen, Philippe, Walter, Guillaume, Mériguet, Anne-Laure, Rollet, and Maguy, Jaber
Subjects: sem-edx, xrd, celadonite, glauconite, mossbauer, green earth
Published: 2019

12. Intramolecular Electron Transfers Thwart Bistability in a Pentanuclear Iron Complex

Author: Bertrand Gerey, Jacques Pécaut, Eric Gouré, Jean-Marc Latour, Martin Clémancey, Geneviève Blondin, Florian Molton, Marie-Noëlle Collomb, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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)
Subjects: Spin states, 010405 organic chemistry, Chemistry, Inorganic chemistry, Electron, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Redox, 0104 chemical sciences, Ion, Inorganic Chemistry, Crystallography, chemistry.chemical_compound, Intramolecular force, Mössbauer spectroscopy, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Bulk electrolysis, Physical and Theoretical Chemistry, Acetonitrile
Abstract: International audience; With the intention to investigate the redox properties of polynuclear complexes as previously reported for the pentamanganese complex [{Mn(II)(μ-bpp)3}2Mn(III)Mn(II)2(μ3-O)](3+) (2(3+)), we focused on the analogous pentairon complex that was previously isolated as all-ferrous. As Masaoka and co-workers recently published, aerobic synthesis leads to the [{Fe(II)(μ-bpp)3}2Fe(III)Fe(II)2(μ3-O)](3+) complex (1(3+)). This species exhibits in acetonitrile solution four reversible one-electron oxidation waves. Accordingly, the three oxidized species 1(4+), 1(5+), and 1(6+) with a 3Fe(II)2Fe(III), 2Fe(II)3Fe(III), and 1Fe(II)4Fe(III) composition, respectively, were generated by bulk electrolysis and isolated. Mössbauer spectroscopy allowed us to determine the spin states of all the iron ions and to unambiguously locate the sites of the successive oxidations. They all occur in the μ3-oxo core except for the 1(4+) to 1(5+) process that presents a striking electronic rearrangement, with both metals in axial position being oxidized while the core is reduced to the [Fe(III)Fe(II)2(μ3-O)](5+) oxidation level. This strongly differs from the redox behavior of the Mn5 system. The origin of this electronic switch is discussed.
Published: 2016
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13. Revisiting the identification of commercial and historical green earth pigments

Author: Helen Glanville, Geneviève Blondin, Anne-Claire Giot, Alice Gimat, Martin Clémancey, Maguy Jaber, Pauline Martinetto, Agathe Fanost, Anne-Laure Rollet, Philippe Walter, Laurence de Viguerie, Fabrice Gaslain, Guillaume Mériguet, PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Archéologie Moléculaire et Structurale (LAMS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (NEEL - MRS), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Centre des Matériaux (CDM), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (MRS), Centre des Matériaux (MAT), and MINES ParisTech - École nationale supérieure des mines de Paris
Subjects: XRD, Energy-dispersive X-ray spectroscopy, Mid infrared, Mineralogy, earth, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Mossbauer, SEM-EDS, Pigment, Colloid and Surface Chemistry, Celadonite, Glauconite, [PHYS]Physics [physics], [SHS.ART]Humanities and Social Sciences/Art and art history, 021001 nanoscience & nanotechnology, 0104 chemical sciences, visual_art, visual_art.visual_art_medium, engineering, Earth (chemistry), 0210 nano-technology, Geology
Abstract: International audience; Green earth is a common green pigment based on celadonite and glauconite, used since Antiquity by artists. Two geological minerals, eight commercial green earth pigments and a sample taken from a historical location in Monte Baldo were characterized. A set of different techniques including X-Ray diffraction (XRD), scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS) and numerous spectroscopies: spectrophotocolorimetry, near and mid infrared, Raman, Mössbauer were used to identify the structure and composition of the different earths. The results highlight complex composition with the presence of various phases, which can be due to the pigment sampling at a different location in the same deposit. Mobile and non-invasive analyses were carried out in order to suggest a protocol for the identification of green earth in artworks, and more specifically to distinguish celadonite and glauconite. With the available mobile non-invasive techniques, and the above analyses on the raw pigments, the green area in Nicolas Poussin’s painting, Bacchanales d’enfants (Galleria Nazionale d’Arte Antica (GNAA), Rome) was examined as a case study.
Published: 2020
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14. Selective C–H halogenation over hydroxylation by non-heme iron(IV)-oxo

Author: Martin Clémancey, Jean-Marc Latour, Debabrata Maiti, Gopalan Rajaraman, Jyoti Prasad Biswas, Asmita Sen, Sujoy Rana, Geneviève Blondin, Department of Chemistry [Mumbai], Indian Institute of Technology Bombay (IIT Bombay), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: chemistry.chemical_classification, inorganic chemicals, 010405 organic chemistry, Ligand, Halide, Halogenation, General Chemistry, 010402 general chemistry, Hydrogen atom abstraction, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Hydroxylation, chemistry.chemical_compound, Chemistry, Enzyme, chemistry, Halogen, [CHIM]Chemical Sciences, Selectivity
Abstract: Synthetic non-heme iron-oxo and iron-halide complexes promote selective halogenation of the sp3-C–H bonds via hydrogen atom abstraction and halide rebound phenomenon., Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C–H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C–H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.
Published: 2018
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15. Contribution of Mössbauer spectroscopy to the investigation of Fe/S biogenesis

Author: Martin Clémancey, Geneviève Blondin, Jean-Marc Latour, Ricardo Garcia-Serres, Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), ANR-14-CE09-0026,FRATISCA,Mieux comprendre les stades précoces et tardifs de l'assemblage des noyaux Fe-S dans la mitochondrie(2014), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 0301 basic medicine, 030102 biochemistry & molecular biology, biology, Chemistry, Iron–sulfur cluster, Vacuole, Mitochondrion, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Biochemistry, Inorganic Chemistry, 03 medical and health sciences, Cytosol, chemistry.chemical_compound, 030104 developmental biology, Iron-sulfur protein, Mössbauer spectroscopy, biology.protein, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Spectroscopy, Biogenesis
Abstract: Fe/S cluster biogenesis involves a complex machinery comprising several mitochondrial and cytosolic proteins. Fe/S cluster biosynthesis is closely intertwined with iron trafficking in the cell. Defects in Fe/S cluster elaboration result in severe diseases such as Friedreich ataxia. Deciphering this machinery is a challenge for the scientific community. Because iron is a key player, 57Fe-Mossbauer spectroscopy is especially appropriate for the characterization of Fe species and monitoring the iron distribution. This minireview intends to illustrate how Mossbauer spectroscopy contributes to unravel steps in Fe/S cluster biogenesis. Studies were performed on isolated proteins that may be present in multiple protein complexes. Since a few decades, Mossbauer spectroscopy was also performed on whole cells or on isolated compartments such as mitochondria and vacuoles, affording an overview of the iron trafficking. This minireview aims at presenting selected applications of 57Fe-Mossbauer spectroscopy to Fe/S cluster biogenesis.
Published: 2018
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16. Development of a rubredoxin-type center embedded in a de novo designed three-helix bundle

Author: Tyler B. J. Pinter, Jean-Marc Latour, Vincent L. Pecoraro, Geneviève Blondin, Alison G. Tebo, Nicolai Lehnert, Ricardo Garcia-Serres, Cédric Tard, Olivier Sénèque, Amy L. Speelman, James E. Penner-Hahn, University of Michigan [Ann Arbor], University of Michigan System, Department of Chemistry and Biophysics, University of Michigan, University of Michigan System-University of Michigan System, Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de chimie moléculaire (LCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and École polytechnique (X)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, Protein Conformation, alpha-Helical, Circular dichroism, Iron, Protein design, 010402 general chemistry, Ferric Compounds, 01 natural sciences, Biochemistry, Article, law.invention, Electron Transport, Electron transfer, Protein structure, law, Rubredoxin, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Electron paramagnetic resonance, Helix bundle, 010405 organic chemistry, Magnetic circular dichroism, Chemistry, Circular Dichroism, Rubredoxins, Electron Spin Resonance Spectroscopy, 0104 chemical sciences, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Crystallography, Oxidation-Reduction
Abstract: Protein design is a powerful tool for interrogating the basic requirements for the function of a metal site in a way that allows for the selective incorporation of elements that are important for function. Rubredoxins are small electron transfer proteins with a reduction potential centered near 0 mV (vs normal hydrogen electrode). All previous attempts to design a rubredoxin site have focused on incorporating the canonical CXXC motifs in addition to reproducing the peptide fold or using flexible loop regions to define the morphology of the site. We have produced a rubredoxin site in an utterly different fold, a three-helix bundle. The spectra of this construct mimic the ultraviolet–visible, Mössbauer, electron paramagnetic resonance, and magnetic circular dichroism spectra of native rubredoxin. Furthermore, the measured reduction potential suggests that this rubredoxin analogue could function similarly. Thus, we have shown that an α-helical scaffold sustains a rubredoxin site that can cycle with the desired potential between the Fe(II) and Fe(III) states and reproduces the spectroscopic characteristics of this electron transport protein without requiring the classic rubredoxin protein fold.
Published: 2018
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17. Elucidating Dramatic Ligand Effects on SET Processes: Iron Hydride versus Iron Borohydride Catalyzed Reductive Radical Cyclization of Unsaturated Organic Halides

Author: Louis Fensterbank, Anny Jutand, Sara H. Kyne, Martin Clémancey, Geneviève Blondin, Guillaume Lefèvre, Cyril Ollivier, Etienne Derat, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE07-0017,SIROCCO,CATALYSEURS STABLES A BASE DE FER POUR LE DEVELOPPEMENT DE FORMATIONS DE LIAISONS C-C PAR COUPLAGE CROISE(2016), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Iron hydride, Diphenylphosphine, 010405 organic chemistry, Chemistry, Ligand, Hydride, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Photochemistry, Borohydride, F160 Organic Chemistry, 01 natural sciences, Medicinal chemistry, Radical cyclization, 0104 chemical sciences, F161 Organometallic Chemistry, Inorganic Chemistry, chemistry.chemical_compound, F100 Chemistry, [CHIM]Chemical Sciences, Reactivity (chemistry), Physical and Theoretical Chemistry, Acetonitrile
Abstract: International audience; An iron(II) borohydride complex ([(η1-H3BH)FeCl(NCCH3)4]) is employed as the precatalyst in iron-catalyzed radical cyclizations of unsaturated organic halides in the presence of NaBH4. Mechanistic investigations have established that the ligand bound to the metal center (acetonitrile versus ethylenebis(diphenylphosphine) (dppe)) plays a crucial role in the structure and reactivity of the active anionic iron(I) hydride ([HFeCl(dppe)2]−) and borohydride ([(η1-H3BH)FeCl(NCCH3)4]−) with unsaturated haloacetals. This work provides new insights into iron(I) hydride and borohydride species and their potential implication in single-electron processes.
Published: 2017
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18. ISCA1 is essential for mitochondrial Fe4S4 biogenesis in vivo

Author: Amélie Weiss, Marc-André Hograindleur, Martin Clémancey, Ioannis Sanakis, Hélène Puccio, Marjorie Fournier, Sandrine Ollagnier de Choudens, Pascale Koebel, Stéphane Schmucker, Aurélie Eisenmann, Geneviève Blondin, Nadia Messaddeq, Lena Kristina Beilschmidt, Alain Martelli, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Chaire Génétique Humaine, Collège de France (CdF (institution)), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Sir William Dunn School of Pathology [Oxford], University of Oxford [Oxford], NCSR, Demokritos, Institut de Science des Matériaux, NCSR, Demokritos, Institut de Science des Matériaux Attiki, Grèce., Rare Disease Research Unit, Pfizer Inc, Pfizer, Collège de France - Chaire Génétique Humaine, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and University of Oxford
Subjects: 0301 basic medicine, Cloning, Gene knockdown, Multidisciplinary, 030102 biochemistry & molecular biology, Science, General Physics and Astronomy, General Chemistry, Plasma protein binding, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, Aconitase, General Biochemistry, Genetics and Molecular Biology, Cell biology, 03 medical and health sciences, 030104 developmental biology, In vivo, Gene expression, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Binding site, Biogenesis
Abstract: Mammalian A-type proteins, ISCA1 and ISCA2, are evolutionarily conserved proteins involved in iron–sulfur cluster (Fe–S) biogenesis. Recently, it was shown that ISCA1 and ISCA2 form a heterocomplex that is implicated in the maturation of mitochondrial Fe4S4 proteins. Here we report that mouse ISCA1 and ISCA2 are Fe2S2-containing proteins that combine all features of Fe–S carrier proteins. We use biochemical, spectroscopic and in vivo approaches to demonstrate that despite forming a complex, ISCA1 and ISCA2 establish discrete interactions with components of the late Fe–S machinery. Surprisingly, knockdown experiments in mouse skeletal muscle and in primary cultures of neurons suggest that ISCA1, but not ISCA2, is required for mitochondrial Fe4S4 proteins biogenesis. Collectively, our data suggest that cellular processes with different requirements for ISCA1, ISCA2 and ISCA1–ISCA2 complex seem to exist.
Published: 2017
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19. Structural Insights into the Nature of Fe 0 and Fe I Low-Valent Species Obtained upon the Reduction of Iron Salts by Aryl Grignard Reagents

Author: Jean-Marc Latour, Geneviève Blondin, Martin Clémancey, Thibault Cantat, Guillaume Lefèvre, Pierre Dorlet, 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), Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Stress Oxydants et Détoxication (LSOD), Département Biochimie, Biophysique et Biologie Structurale (B3S), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CEA, CNRS, the ANR (Project JCJC SIROCCO-16 (G.L.), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), Laboratoire de Chimie et Biologie des Métaux ( LCBM - UMR 5249 ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) ( LCMCE ), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) ( NIMBE UMR 3685 ), Institut Rayonnement Matière de Saclay ( IRAMIS ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut Rayonnement Matière de Saclay ( IRAMIS ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Stress Oxydants et Détoxication ( LSOD ), Département Biochimie, Biophysique et Biologie Structurale ( B3S ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), ANR-10-INBS-05-01/10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée ( 2010 ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Inorganic chemistry, 010402 general chemistry, 01 natural sciences, DFT, law.invention, Inorganic Chemistry, chemistry.chemical_compound, law, Mössbauer spectroscopy, Polymer chemistry, Physical and Theoretical Chemistry, Electron paramagnetic resonance, Tetrahydrofuran, 010405 organic chemistry, Ligand, Aryl, [CHIM.MATE]Chemical Sciences/Material chemistry, Toluene, Low - valent iron, 0104 chemical sciences, chemistry, Reagent, [ CHIM.MATE ] Chemical Sciences/Material chemistry, Proton NMR, EPR spectroscopy
Abstract: International audience; Mechanistic studies of the reduction of Fe III and Fe II salts by aryl Grignard reagents in toluene/tetrahydrofuran mixtures in the absence of a supporting ligand, as well as structural insights regarding the nature of the low-valent iron species obtained at the end of this reduction process, are reported. It is shown that several reduction pathways can be followed, depending on the starting iron precursor. We demonstrate, moreover, that these pathways lead to a mixture of Fe 0 and Fe I complexes regardless of the nature of the precursor. Mö ssbauer and 1 H NMR spectroscopies suggest that diamagnetic 16-electron bisarene complexes such as (η 4-C 6 H 5 Me) 2 Fe 0 can be formed as major species (85% of the overall iron quantity). The formation of a η 6-arene-ligated low-spin Fe I complex as a minor species (accounting for ca. 15% of the overall iron quantity) is attested by Mö ssbauer spectroscopy, as well as by continuous-wave electron paramagnetic resonance (EPR) and pulsed-EPR (HYSCORE) spectroscopies. The nature of the Fe I coordination sphere is discussed by means of isotopic labeling experiments and density functional theory calculations. It is shown that the most likely low-spin Fe I candidate obtained in these systems is a diphenylarene-stabilized species [(η 6-C 6 H 5 Me)Fe I Ph 2 ] − exhibiting an idealized C 2v topology. This enlightens the nature of the lowest valence states accommodated by iron during the reduction of Fe III and Fe II salts by aryl Grignard reagents in the absence of any additional coligand, which so far remained rather unknown. The reactivity of these low-valent Fe I and Fe 0 complexes in aryl−heteroaryl Kumada cross-coupling conditions has also been investigated, and it is shown that the zerovalent Fe 0 species can be used efficiently as a precursor in this reaction, whereas the Fe I oxidation state does not exhibit any reactivity.
Published: 2017
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20. Single Asparagine to Arginine Mutation Allows PerR to Switch from PerR Box to Fur Box

Author: Christelle Caux-Thang, Arhamatoulaye Maïga, Ramakrishnan Sethu, Aubérie Parent, Jean-Marc Latour, Geneviève Blondin, Victor Duarte, 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)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: DNA, Bacterial, Transcription, Genetic, Molecular Sequence Data, Virulence, Bacillus subtilis, Biology, Arginine, Biochemistry, DNA sequencing, 03 medical and health sciences, chemistry.chemical_compound, Bacterial Proteins, Transcription (biology), [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Protein Interaction Domains and Motifs, Nucleotide, Asparagine, Gene, 030304 developmental biology, Genetics, chemistry.chemical_classification, 0303 health sciences, Base Sequence, integumentary system, 030306 microbiology, Gene Expression Regulation, Bacterial, General Medicine, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Repressor Proteins, chemistry, Mutation, bacteria, Molecular Medicine, DNA, Protein Binding
Abstract: International audience; Fur family proteins, ubiquitous in prokaryotes, play a pivotal role in microbial survival and virulence in most pathogens. Metalloregulators, such as Fur and PerR, regulate the transcription of genes connected to iron homeostasis and response to oxidative stress, respectively. In Bacillus subtilis, Fur and PerR bind with high affinity to DNA sequences differing at only two nucleotides. In addition to these differences in the PerR and Fur boxes, we identify in this study a residue located on the DNA binding motif of the Fur protein that is critical to discrimination between the two close DNA sequences. Interestingly, when this residue is introduced into PerR, it lowers the affinity of PerR for its own DNA target but confers to the protein the ability to interact strongly with the Fur DNA binding sequence. The present data show how two closely related proteins have distinct biological properties just by changing a single residue.
Published: 2014
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21. Single Glutamate to Aspartate Mutation Makes Ferric Uptake Regulator (Fur) as Sensitive to H2O2as Peroxide Resistance Regulator (PerR)

Author: Aubérie Parent, Christelle Caux-Thang, Luca Signor, Martin Clémancey, Ramakrishnan Sethu, Geneviève Blondin, Pascale Maldivi, Victor Duarte, and Jean-Marc Latour
Subjects: 0303 health sciences, 03 medical and health sciences, General Medicine, 010402 general chemistry, 01 natural sciences, 030304 developmental biology, 0104 chemical sciences
Published: 2013
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22. ISCA1 is essential for mitochondrial Fe

Author: Lena Kristina, Beilschmidt, Sandrine, Ollagnier de Choudens, Marjorie, Fournier, Ioannis, Sanakis, Marc-André, Hograindleur, Martin, Clémancey, Geneviève, Blondin, Stéphane, Schmucker, Aurélie, Eisenmann, Amélie, Weiss, Pascale, Koebel, Nadia, Messaddeq, Hélène, Puccio, and Alain, Martelli
Subjects: Aconitate Hydratase, Iron-Sulfur Proteins, Male, Binding Sites, Sensory Receptor Cells, Genetic Vectors, Primary Cell Culture, Gene Expression, Recombinant Proteins, Article, Mice, Inbred C57BL, Mitochondrial Proteins, Mice, Spectroscopy, Mossbauer, Escherichia coli, Animals, Female, Protein Interaction Domains and Motifs, Cloning, Molecular, Protein Multimerization, Muscle, Skeletal, Protein Binding
Abstract: Mammalian A-type proteins, ISCA1 and ISCA2, are evolutionarily conserved proteins involved in iron–sulfur cluster (Fe–S) biogenesis. Recently, it was shown that ISCA1 and ISCA2 form a heterocomplex that is implicated in the maturation of mitochondrial Fe4S4 proteins. Here we report that mouse ISCA1 and ISCA2 are Fe2S2-containing proteins that combine all features of Fe–S carrier proteins. We use biochemical, spectroscopic and in vivo approaches to demonstrate that despite forming a complex, ISCA1 and ISCA2 establish discrete interactions with components of the late Fe–S machinery. Surprisingly, knockdown experiments in mouse skeletal muscle and in primary cultures of neurons suggest that ISCA1, but not ISCA2, is required for mitochondrial Fe4S4 proteins biogenesis. Collectively, our data suggest that cellular processes with different requirements for ISCA1, ISCA2 and ISCA1–ISCA2 complex seem to exist., The mitochondrial proteins ISCA1 and ISCA2 form a complex that is involved in the biogenesis of Fe–S clusters. Here the authors report that ISCA1 and ISCA2 interact differently with proteins of the Fe–S machinery and that under certain conditions, ISCA2 seems dispensable for Fe–S biogenesis.
Published: 2016

23. Redox Control of the Human Iron-Sulfur Repair Protein MitoNEET Activity via Its Iron-Sulfur Cluster

Author: Eric Guittet, Jérôme Santolini, Martin Clémancey, Jean-Marc Latour, Ewen Lescop, Cécile Bouton, Geneviève Blondin, Sergio Gonçalves, Cécile Mons, Marie-Pierre Golinelli-Cohen, Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), 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), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles ( ICSN ), Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Chimie et Biologie des Métaux ( LCBM - UMR 5249 ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 'Avenir' U983 Hopital Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale (INSERM), 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), Stress Oxydants et Détoxication (LSOD), Département Biochimie, Biophysique et Biologie Structurale (B3S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Iron-Sulfur Proteins, 0301 basic medicine, nuclear magnetic resonance (NMR), [SDV]Life Sciences [q-bio], Mossbauer spectroscopy, Regulator, Iron–sulfur cluster, chemistry.chemical_element, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, medicine.disease_cause, Biochemistry, Redox, Fe-S transfer, Mitochondrial Proteins, 03 medical and health sciences, chemistry.chemical_compound, Protein stability, medicine, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Fe-S lability, Molecular Biology, [ SDV.BBM ] Life Sciences [q-bio]/Biochemistry, Molecular Biology, iron-sulfur protein, [ SDV ] Life Sciences [q-bio], 030102 biochemistry & molecular biology, [ SDV.BC ] Life Sciences [q-bio]/Cellular Biology, [ CHIM.COOR ] Chemical Sciences/Coordination chemistry, Cell Biology, Acceptor, Sulfur, Oxidative Stress, Cytosol, Metabolism, 030104 developmental biology, chemistry, protein stability, mitoNEET, Raman spectroscopy, Biophysics, Oxidation-Reduction, Oxidative stress
Abstract: International audience; Human mitoNEET (mNT) is the first identified Fe-S protein of the mammalian outer mitochondrial membrane. Recently, mNT has been implicated in cytosolic Fe-S repair of a key regulator of cellular iron homeostasis. Here, we aimed to decipher the mechanism by which mNT triggers its Fe-S repair capacity. By using tightly controlled reactions combined with complementary spectroscopic approaches, we have determined the differential roles played by both the redox state of the mNT cluster and dioxygen in cluster transfer and protein stability. We unambiguously demonstrated that only the oxidized state of the mNT cluster triggers cluster transfer to a generic acceptor protein and that dioxygen is neither required for the cluster transfer reaction nor does it affect the transfer rate. In the absence of apo-acceptors, a large fraction of the oxidized holo-mNT form is converted back to reduced holo-mNT under low oxygen tension. Reduced holo-mNT, which holds a [2Fe-2S](+)with a global protein fold similar to that of the oxidized form is, by contrast, resistant in losing its cluster or in transferring it. Our findings thus demonstrate that mNT uses an iron-based redox switch mechanism to regulate the transfer of its cluster. The oxidized state is the "active state," which reacts promptly to initiate Fe-S transfer independently of dioxygen, whereas the reduced state is a "dormant form." Finally, we propose that the redox-sensing function of mNT is a key component of the cellular adaptive response to help stress-sensitive Fe-S proteins recover from oxidative injury.
Published: 2016
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24. An N-bridged high-valent diiron–oxo species on a porphyrin platform that can oxidize methane

Author: Leonardo X Alvarez, Evgeny V Kudrik, Martin Clémancey, Florian Albrieux, Patrick Dubourdeaux, Pavel Afanasiev, Jean-Marc Latour, Denis Bouchu, Alexander B. Sorokin, Geneviève Blondin, Sergey E. Nefedov, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), 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), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences [Moscow] (RAS), BIOVERT (BIOVERT), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Claude Bernard Lyon 1 (UCBL), RAFFINAGE (RAFFINAGE), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Spectrometry, Mass, Electrospray Ionization, Reaction mechanism, Metalloporphyrins, Nitrogen, Methane monooxygenase, Stereochemistry, General Chemical Engineering, Electrospray ionization, Context (language use), 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Oxidizing agent, Tetraphenylporphyrin, [CHIM.COOR]Chemical Sciences/Coordination chemistry, biology, 010405 organic chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, [SDE.ES]Environmental Sciences/Environmental and Society, Porphyrin, 0104 chemical sciences, Chlorobenzoates, chemistry, 13. Climate action, biology.protein, Methane, Oxidation-Reduction
Abstract: BIOVERT:RAFFINAGE+EKU:PAF:ASO; High-valent oxo-metal complexes are involved in key biochemical processes of selective oxidation and removal of xenobiotics. The catalytic properties of cytochrome P-450 and soluble methane monooxygenase enzymes are associated with oxo species on mononuclear iron haem and diiron non-haem platforms, respectively. Bio-inspired chemical systems that can reproduce the fascinating ability of these enzymes to oxidize the strongest C-H bonds are the focus of intense scrutiny. In this context, the development of highly oxidizing diiron macrocyclic catalysts requires a structural determination of the elusive active species and elucidation of the reaction mechanism. Here we report the preparation of an Fe(IV)(mu-nitrido)Fe(IV) = O tetraphenylporphyrin cation radical species at -90 degrees C, characterized by ultraviolet-visible, electron paramagnetic resonance and Mossbauer spectroscopies and by electrospray ionization mass spectrometry. This species exhibits a very high activity for oxygen-atom transfer towards alkanes, including methane. These findings provide a foundation on which to develop efficient and clean oxidation processes, in particular transformations of the strongest C-H bonds.
Published: 2012
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25. Biologically Relevant Heterodinuclear Iron–Manganese Complexes

Author: Colette Lebrun, Lionel Dubois, Geneviève Blondin, Martin Clémancey, Jacques Pécaut, Jean-Marc Latour, Florian Molton, Michaël Carboni, 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), Département de Chimie Moléculaire (DCM), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Models, Molecular, Pyridines, Iron, chemistry.chemical_element, Manganese, Crystallography, X-Ray, Ligands, 010402 general chemistry, Ferric Compounds, 01 natural sciences, law.invention, Inorganic Chemistry, Cresols, Electron transfer, Coordination Complexes, law, Mössbauer spectroscopy, Antiferromagnetism, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Ferrous Compounds, Physical and Theoretical Chemistry, Electron paramagnetic resonance, 010405 organic chemistry, Chemistry, Ligand, Magnetic susceptibility, 0104 chemical sciences, Crystallography, Proton NMR
Abstract: International audience; The heterodinuclear complexes [Fe(III)Mn(II)(L-Bn)(μ-OAc)(2)](ClO(4))(2) (1) and [Fe(II)Mn(II)(L-Bn)(μ-OAc)(2)](ClO(4)) (2) with the unsymmetrical dinucleating ligand HL-Bn {[2-bis[(2-pyridylmethyl)aminomethyl]]-6-[benzyl-2-(pyridylmethyl)aminomethyl]-4-methylphenol} were synthesized and characterized as biologically relevant models of the new Fe/Mn class of nonheme enzymes. Crystallographic studies have been completed on compound 1 and reveal an Fe(III)Mn(II)μ-phenoxobis(μ-carboxylato) core. A single location of the Fe(III) ion in 1 and of the Fe(II) ion in 2 was demonstrated by Mössbauer and (1)H NMR spectroscopies, respectively. An investigation of the temperature dependence of the magnetic susceptibility of 1 revealed a moderate antiferromagnetic interaction (J = 20 cm(-1)) between the high-spin Fe(III) and Mn(II) ions in 1, which was confirmed by Mössbauer and electron paramagnetic resonance (EPR) studies. The electrochemical properties of complex 1 are described. A quasireversible electron transfer at -40 mV versus Ag/AgCl corresponding to the Fe(III)Mn(II)/Fe(II)Mn(II) couple appears in the cyclic voltammogram. Thorough investigations of the Mössbauer and EPR signatures of complex 2 were performed. The analysis allowed evidencing of a weak antiferromagnetic interaction (J = 5.72 cm(-1)) within the Fe(II)Mn(II) pair consistent with that deduced from magnetic susceptibility measurements (J = 6.8 cm(-1)). Owing to the similar value of the Fe(II) zero-field splitting (D(Fe) = 3.55 cm(-1)), the usual treatment within the strong exchange limit was precluded and a full analysis of the electronic structure of the ground state of complex 2 was developed. This situation is reminiscent of that found in many diiron and iron-manganese enzyme active sites.
Published: 2012
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26. Correction to: Contribution of Mössbauer spectroscopy to the investigation of Fe/S biogenesis

Author: Martin Clémancey, Jean-Marc Latour, Ricardo Garcia-Serres, and Geneviève Blondin
Subjects: Iron-Sulfur Proteins, Fe/S biogenesis, Mössbauer spectroscopy, Iron–sulfur cluster, Chemistry, Iron, Correction, Internet portal, Library science, Biochemistry, Inorganic Chemistry, Spectroscopy, Mossbauer, Humans, Histidine, Minireview, Iron trafficking, Biogenesis
Abstract: Fe/S cluster biogenesis involves a complex machinery comprising several mitochondrial and cytosolic proteins. Fe/S cluster biosynthesis is closely intertwined with iron trafficking in the cell. Defects in Fe/S cluster elaboration result in severe diseases such as Friedreich ataxia. Deciphering this machinery is a challenge for the scientific community. Because iron is a key player, 57Fe-Mössbauer spectroscopy is especially appropriate for the characterization of Fe species and monitoring the iron distribution. This minireview intends to illustrate how Mössbauer spectroscopy contributes to unravel steps in Fe/S cluster biogenesis. Studies were performed on isolated proteins that may be present in multiple protein complexes. Since a few decades, Mössbauer spectroscopy was also performed on whole cells or on isolated compartments such as mitochondria and vacuoles, affording an overview of the iron trafficking. Graphical abstract This minireview aims at presenting selected applications of 57Fe-Mössbauer spectroscopy to Fe/S cluster biogenesis
Published: 2018
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27. Post-translational Modification of Ribosomal Proteins

Author: John F. Hunt, Gaetano T. Montelione, Etienne Mulliez, Jean-Marc Latour, Martin Clémancey, Mohamed G. Atta, Simon Arragain, Farhad Forouhar, Thierry Douki, Marc Fontecave, Ricardo Garcia-Serres, Helen Neely, and Geneviève Blondin
Subjects: 0303 health sciences, biology, TRNA Methyltransferase, Cell Biology, Isomerase, 010402 general chemistry, biology.organism_classification, 01 natural sciences, Biochemistry, 0104 chemical sciences, Structural genomics, 03 medical and health sciences, Protein structure, Ribosomal protein, Thermotoga maritima, Transfer RNA, TIM barrel, Molecular Biology, 030304 developmental biology
Abstract: Post-translational modifications of ribosomal proteins are important for the accuracy of the decoding machinery. A recent in vivo study has shown that the rimO gene is involved in generation of the 3-methylthio derivative of residue Asp-89 in ribosomal protein S12 (Anton, B. P., Saleh, L., Benner, J. S., Raleigh, E. A., Kasif, S., and Roberts, R. J. (2008) Proc. Natl. Acad. Sci. U. S. A. 105, 1826-1831). This reaction is formally identical to that catalyzed by MiaB on the C2 of adenosine 37 near the anticodon of several tRNAs. We present spectroscopic evidence that Thermotoga maritima RimO, like MiaB, contains two [4Fe-4S] centers, one presumably bound to three invariant cysteines in the central radical S-adenosylmethionine (AdoMet) domain and the other to three invariant cysteines in the N-terminal UPF0004 domain. We demonstrate that holo-RimO can specifically methylthiolate the aspartate residue of a 20-mer peptide derived from S12, yielding a mixture of mono- and bismethylthio derivatives. Finally, we present the 2.0 A crystal structure of the central radical AdoMet and the C-terminal TRAM (tRNA methyltransferase 2 and MiaB) domains in apo-RimO. Although the core of the open triose-phosphate isomerase (TIM) barrel of the radical AdoMet domain was conserved, RimO showed differences in domain organization compared with other radical AdoMet enzymes. The unusually acidic TRAM domain, likely to bind the basic S12 protein, is located at the distal edge of the radical AdoMet domain. The basic S12 protein substrate is likely to bind RimO through interactions with both the TRAM domain and the concave surface of the incomplete TIM barrel. These biophysical results provide a foundation for understanding the mechanism of methylthioation by radical AdoMet enzymes in the MiaB/RimO family.
Published: 2010
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28. Trinuclear Terpyridine Frustrated Spin System with a MnIV3O4 Core: Synthesis, Physical Characterization, and Quantum Chemical Modeling of Its Magnetic Properties

Author: Frank Neese, Dimitrios A. Pantazis, Alain Deronzier, Carole Duboc, Carole Baffert, Allan G. Blackman, Marie-Noëlle Collomb, Maylis Orio, Geneviève Blondin, Département de Chimie Moléculaire (DCM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Joseph Fourier - Grenoble 1 (UJF), Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Joseph Fourier - Grenoble 1 (UJF), Department of Chemistry, University of Otago [Dunedin, Nouvelle-Zélande], 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), University of Bonn, Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universität Bonn = University of Bonn
Subjects: Models, Molecular, Spin states, Pyridines, chemistry.chemical_element, Manganese, Crystallography, X-Ray, 010402 general chemistry, 01 natural sciences, law.invention, Inorganic Chemistry, Magnetics, chemistry.chemical_compound, law, Computational chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Electron paramagnetic resonance, Molecular Structure, 010405 organic chemistry, Electron Spin Resonance Spectroscopy, Oxides, Magnetic susceptibility, 0104 chemical sciences, Crystallography, Manganese Compounds, Models, Chemical, chemistry, Quantum Theory, Density functional theory, Terpyridine, Ground state, Oxidation-Reduction, Monoclinic crystal system
Abstract: International audience; The trinuclear oxo bridged manganese cluster, [Mn(IV)(3)O(4)(terpy)(terpyO(2))(2)(H(2)O)](S(2)O(8))(2) (5) (terpy = 2,2':2'',6'-terpyridine and terpyO(2) = 2,2':2'',6'-terpyridine 1,1''-dioxide), was isolated in an acidic aqueous medium from the reaction of MnSO(4), terpy, and oxone as chemical oxidant. The terpyO(2) ligands were generated in situ during the synthesis by partial oxidation of terpy. The complex crystallizes in the monoclinic space group P21/n with a = 14.251(5) A, b = 15.245(5) A, c = 24.672(5) A, alpha = 90.000(5) degrees, beta = 92.045(5) degrees, gamma = 90.000(5) degrees, and Z = 4. The triangular {Mn(IV)(3)O(4)}(4+) core observed in this complex is built up of a basal Mn(mu-O)(2)Mn unit where each Mn ion is linked to an apical Mn ion via mono(mu-O) bridges. The facial coordination of the two tridentate terpyO(2) ligands to the Mn(mu-O)(2)Mn unit allows the formation of the triangular core. 5 is also the first structurally characterized Mn complex with polypyridinyl N-oxide ligands. The variable-temperature magnetic susceptibility data for this complex, in the range of 10-300 K, are consistent with an S = 1/2 ground state and were fit using the spin Hamiltonian H(eff) with S(1) = S(2) = S(3) = 3/2, J(a) = -37 (+/-0.5) and J(b) = -53 (+/-1) cm(-1), where J(a) and J(b) are exchange constants through the mono-mu-oxo and the di-mu-oxo bridges, respectively. The doublet ground spin state of 5 is confirmed by EPR spectroscopic measurements. Density functional theory (DFT) calculations based on the broken symmetry approach reproduce the magnetic properties of 5 very well (calculated values: J(a) = -39.4 and J(b) = -55.9 cm(-1)), thus confirming the capability of this quantum chemical method for predicting the magnetic behavior of clusters involving more than two metal ions. The nature of the ground spin state of the magnetic {Mn(IV)(3)O(4)}(4+) core and the role of ancillary ligands on the magnitude of J are also discussed.
Published: 2009
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29. Structural and functional characterization of 2-oxo-histidine in oxidized PerR protein

Author: Jean-Marc Latour, Michel Jaquinod, Jean-Luc Ravanat, Abdelnasser El Ghazouani, David Lascoux, Franck Borel, Christelle Caux-Thang, Lilian Jacquamet, Jean Luc Ferrer, Daouda A K Traore, Geneviève Blondin, Victor Duarte, 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), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lésions des Acides Nucléiques (LAN), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude de la dynamique des protéomes (LEDyP), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire de Cristallographie et Cristallogénèse des Protéines (LCCP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Laboratoire de Spectrométrie de Masse des Protéines (LSMP)
Subjects: DNA, Bacterial, Models, Molecular, Protein Conformation, Stereochemistry, chemistry.chemical_element, Regulatory site, Zinc, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Peroxide, Mass Spectrometry, Metal, 03 medical and health sciences, chemistry.chemical_compound, Residue (chemistry), Protein structure, Bacterial Proteins, Histidine, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Hydrogen peroxide, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Gene Expression Regulation, Bacterial, Cell Biology, Repressor Proteins, chemistry, visual_art, visual_art.visual_art_medium, Biophysics, Oxidation-Reduction, Bacillus subtilis, Protein Binding
Abstract: International audience; In Bacillus subtilis, PerR is a metal-dependent sensor of hydrogen peroxide. PerR is a dimeric zinc protein with a regulatory site that coordinates either Fe(2+) (PerR-Zn-Fe) or Mn(2+) (PerR-Zn-Mn). Though most of the peroxide sensors use cysteines to detect H(2)O(2), it has been shown that reaction of PerR-Zn-Fe with H(2)O(2) leads to the oxidation of one histidine residue. Oxidation of PerR leads to the incorporation of one oxygen atom into His37 or His91. This study presents the crystal structure of the oxidized PerR protein (PerR-Zn-ox), which clearly shows a 2-oxo-histidine residue in position 37. Formation of 2-oxo-histidine is demonstrated and quantified by HPLC-MS/MS. EPR experiments indicate that PerR-Zn-H37ox retains a significant affinity for the regulatory metal, whereas PerR-Zn-H91ox shows a considerably reduced affinity for the metal ion. In spite of these major differences in terms of metal binding affinity, oxidation of His37 and/or His91 in PerR prevents DNA binding.
Published: 2008
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30. Deprotonation in Mixed-Valent Diiron(II,III) Complexes with Aniline or Benzimidazole Ligands

Author: Ramachandran Balasubramanian, Martin Clémancey, Jacques Pécaut, Patrick Dubourdeaux, Nathalie Gon, Michaël Carboni, Jean-Marc Latour, Colette Lebrun, Eric Gouré, Geneviève Blondin, Angélique Troussier, Laboratoire de Physicochimie des Métaux en Biologie, Département de Biologie Moléculaire, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Benzimidazole, 010405 organic chemistry, Ligand, Stereochemistry, Nuclear magnetic resonance spectroscopy, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Deprotonation, Aniline, chemistry, Mixed valent, medicine, Ferric, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Isomerization, medicine.drug
Abstract: International audience; We have previously investigated cis/trans isomerization processes in phenoxido-bridged mixed-valent Fe$^{II}$Fe$^{III}$ complexes that contain either one aniline or one anilide ligand. In this work, we compare the properties of similar complexes bearing one terminal protic ligand, either aniline or 1H-benzimidazole. Whatever the ligand, $^1$H NMR spectroscopy clearly evidences that the complexes are present in CH$_3$CN as a mixture of cis- and trans-isomers in a close to 1:1 ratio. We show here that addition of NEt$_3$ indeed allows the deprotonation of these ligands, the resulting complexes bearing either anilide or benzimidazolide that are coordinated to the ferric site. The latter are singular examples of a high-spin ferric ion coordinated to a benzimidazolide ligand. Whereas the trans-isomer of the anilide complex is the overwhelming species, benzimidazolide species are mixtures of cis- and trans-isomers in equal proportions. Moreover, cyclic voltammametry studies show that Fe$^{II}$Fe$^{III}$ complexes with 1H-benzimidazole are more stable than their aniline counterparts, whereas the reverse is observed for the deprotonated species.
Published: 2015
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31. Phosphoester Hydrolysis: The Incoming Substrate Turns the Bridging Hydroxido Nucleophile into a Terminal One

Author: Geneviève Blondin, Jean-François Jacquot, Jacques Pécaut, Michaël Carboni, Jean-Marc Latour, Martin Clémancey, Patrick Dubourdeaux, Angélique Troussier, Colette Lebrun, Eric Gouré, 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), Laboratoire de Physico-chimie des Métaux en Biologie (LPCMB), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: Models, Molecular, phosphate esters, Magnetic Resonance Spectroscopy, Mossbauer spectroscopy, diiron centers, 010402 general chemistry, Ferric Compounds, 01 natural sciences, Catalysis, Spectroscopy, Mossbauer, Hydrolysis, chemistry.chemical_compound, NMR spectroscopy, Nucleophile, Polymer chemistry, Hydroxides, Organic chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Ferrous Compounds, 010405 organic chemistry, Organic Chemistry, General Chemistry, Nuclear magnetic resonance spectroscopy, [CHIM.CATA]Chemical Sciences/Catalysis, Hydrogen-Ion Concentration, Phosphate, Organophosphates, 0104 chemical sciences, binuclear hydrolases, chemistry, Phosphodiester bond, Proton NMR, Hydroxide, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 2,4-Dinitrophenol
Abstract: International audience; Identifying the active nucleophile in hydrolysis reactions catalyzed by binuclear hydrolases is a recurrent problem and a matter of intense debate. We report on the phosphate ester hydrolysis by a (FeFeII)-Fe-III complex of a binucleating ligand. This complex presents activities in the range of those observed for similar biomimetic compounds in the literature. The specific electronic properties of the (FeFeII)-Fe-III complex allowed us to use (HNMR)-H-1 and Mossbauer spectroscopies to investigate the nature of the various species present in the solution in the pH range of 5-10. Both techniques showed that the hydrolysis activity is associated to a -hydroxido (FeFeII)-Fe-III species. Further (HNMR)-H-1 experiments show that binding of anions or the substrate changes this bonding mode suggesting that a terminal hydroxide is the likely nucleophile in these hydrolysis reactions. This view is further supported by the structure determination of the hydrolysis product.
Published: 2015
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32. Dinitrogen Activation Upon Reduction of a Triiron(II) Complex

Author: Forrest T. Sloane, Geneviève Blondin, Leslie J. Murray, Khalil A. Abboud, Ricardo Garcia-Serres, Yousoon Lee, Center for Catalysis, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200 (USA), University of Florida [Gainesville] (UF), 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), Laboratoire de Physico-chimie des Métaux en Biologie (LPCMB), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry, University of Florida, and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)
Subjects: Inorganic chemistry, dinitrogen activation, Protonation, 010402 general chemistry, Medicinal chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Ammonia, Mössbauer spectroscopy, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Indophenol, 010405 organic chemistry, macrobicycles, General Chemistry, General Medicine, iron clusters, redox cooperativity, 0104 chemical sciences, 3. Good health, chemistry, Elemental analysis, Yield (chemistry), cyclophanes, Protonolysis, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Cyclophane
Abstract: International audience; Reaction of a trinuclear iron(II) complex, Fe3Br3L (1), with KC8 under N-2 leads to dinitrogen activation products (2) from which Fe-3(NH)(3)L (2-1; L is a cyclophane bridged by three beta-diketiminate arms) was characterized by X-ray crystallography. H-1 NMR spectra of the protonolysis product of 2 synthesized under N-14(2) and N-15(2) confirm atmospheric N-2 reduction, and ammonia is detected by the indophenol assay (yield similar to 30%). IR and Mossbauer spectroscopy, and elemental analysis on 2 and 2-1 as well as the tri(amido)triiron(II) 3 and tri(methoxo)triiron 4 congeners support our assignment of the reduction product as containing protonated N-atom bridges.
Published: 2015
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33. Synthesis, Structure and Characterisation of a New Trinuclear Di‐ μ ‐phenolato‐ μ ‐carboxylato Mn III Mn II Mn III Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear Mn IV –OH Entities

Author: Elodie Anxolabéhère-Mallart, Geneviève Blondin, Martine Nierlich, Christelle Hureau, and Eric Rivière
Subjects: Schiff base, 010405 organic chemistry, Ligand, Inorganic chemistry, Imine, Crystal structure, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, law.invention, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, Ultraviolet visible spectroscopy, chemistry, law, Pyridine, Acetonitrile, Electron paramagnetic resonance
Abstract: A new trinuclear Mn I I I Mn I I Mn I I I complex has been isolated and X-ray characterised, namely [(py-salpn)Mn I I I (μ-OAc)-Mn I I (μ-OAc)Mn I I I (py-salpn)] 2 + (1), where H 2 py-salpn is the new bulky [N 3 O 2 ] ligand derived from the H 2 salpn Schiff base by the addition of one pyridine arm and the reduction of the imine function. The crystal structure reveals that the complex has a strictly 180° Mn I I I ...Mn I I Mn I I I angle, the Mn I I ion being located at an inversion centre. The complex is valence-trapped, with the terminal Mn I I I ions showing a Jahn-Teller elongation along the pyridine-Mn I I I -acetate axis. The Mn I I ...Mn I I I separation is 3.1224(13) A. The EPR spectra recorded on solid and frozen solutions are consistent with an Mn I I I Mn I I Mn I I I species. The electrochemical response of complex 1 in acetonitrile solution exhibits two, one-electron reduction waves at E 1 / 2 = 0.140 and -0.075V vs. SCE. Phenolato and acetato→Mn I I I ligand-to-metal charge-transfer transitions are detected by UV/Visible spectroscopy at 359 and 587 nm, respectively. Chemical oxidation of an acetonitrile solution with tert-butyl hydroperoxide leads to mononuclear Mn I V -hydroxo species, as evidenced by UV/Visible and EPR spectroscopy as well as ESI mass spectrometry.
Published: 2005
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34. Synthesis and X-ray Structure of the MnIICl2 and MnIIIF2 Complexes of N,N‘-Dimethyl-2,11-diaza[3,3](2,6)pyridinophane. High-Field Electron Paramagnetic Resonance and Density Funtional Theory Studies of the Mn(III) Complex. Evidence for a Low-Lying Spin Triplet State

Author: Carina Riccardo Filippo, Clotilde Policar, Joan Cano, Luba Tchertanov, Jean Guilhem, Michel Delroisse, Jean-Jacques Girerd, Sandrine Poussereau, Geneviève Blondin, and Belén Albela
Subjects: Spin states, 010405 organic chemistry, Chemistry, Crystal structure, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, law.invention, Inorganic Chemistry, Crystallography, Computational chemistry, law, Excited state, Density functional theory, Macrocyclic ligand, Physical and Theoretical Chemistry, Triplet state, Ground state, Electron paramagnetic resonance
Abstract: Two manganese complexes, (py2(NMe)2)MnIICl2 (1) and [(py2(NMe)2)MnIIIF2]+ (2), are here described with the macrocyclic ligand py2(NMe)2 (py2(NMe)2 = N,N‘-dimethyl-2,11-diaza[3,3](2,6)pyridinophane). For both, the crystal structure is reported. The UV−visible spectrum of 2 exhibits a very broad near-infrared (NIR) band corresponding to the transition between the two eg-type orbitals split by the Jahn−Teller effect. A negative D value of ca. −4 cm-1 was estimated by high-field and high-frequency electron paramagnetic resonance (HF-EPR) spectroscopy, which was consistent with symmetry considerations. Density functional theory (DFT) calculations on 2 support the 5B1 electronic ground state predicted from the X-ray structure. Moreover, to explain the large value of the D parameter, a spin triplet first excited spin state was postulated to occur at low energy. This was confirmed by the DFT calculations.
Published: 2005
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35. Synthesis, Structure, and Characterisation of a New Phenolato-Bridged Manganese Complex[Mn2(mL)2]2+: Chemical and Electrochemical Access to a New Mono-μ-Oxo Dimanganese Core Unit

Author: Elodie Anxolabéhère-Mallart, Martine Nierlich, Marie-France Charlot, Laurent Sabater, Geneviève Blondin, Florence Gonnet, Christelle Hureau, and Eric Rivière
Subjects: Ligand, Organic Chemistry, Analytical chemistry, chemistry.chemical_element, Aromaticity, General Chemistry, Manganese, Electrochemistry, Catalysis, law.invention, Crystallography, chemistry, law, Absorption band, Saturated calomel electrode, Cyclic voltammetry, Electron paramagnetic resonance
Abstract: The dinuclear phenolato-bridged complex [(mL)Mn(II)Mn(II)(mL)](ClO(4))(2) (1(ClO(4))(2)) has been obtained with the new [N(4)O] pentadentate ligand mL(-) (mLH=N,N'-bis-(2-pyridylmethyl)-N-(2-hydroxybenzyl)-N'-methyl-ethane-1,2-diamine) and has been characterised by X-ray crystallography. X- and Q-band EPR spectra were recorded and their variation with temperature was examined. All spectra exhibit features extending over 0-800 mT at the X band and over 100-1450 mT at the Q band, features that are usually observed for dinuclear Mn(II) complexes. Cyclic voltammetry of 1 exhibits two irreversible oxidation waves at E(1)(p)=0.89 V and E(2)(p)=1.02 V, accompanied on the reverse scan by an ill-defined cathodic wave at E(1')(p)=0.56 V (all measured versus the saturated calomel electrode (SCE)). Upon chemical oxidation with tBuOOH (10 equiv) at 20 degrees C, 1 is transformed into the mono-mu-oxo species [(mL)Mn(III)-(mu-O)-Mn(III)(mL)](2+) (2), which eventually partially evolves into the di-mu-oxo species [(mL)Mn(III)-(mu-O)(2)-Mn(IV)(mL)](n+) (3) in which one of the aromatic rings of the ligand is decoordinated. The UV/Vis spectrum of 2 displays a large absorption band at 507 nm, which is attributed to a phenolate-->Mn(III) charge-transfer transition. The cyclovoltammogram of 2 exhibits two reversible oxidation waves, at 0.65 and 1.16 V versus the SCE, corresponding to the Mn(III)Mn(III)/Mn(III)Mn(IV) and Mn(III)Mn(IV)/Mn(IV)Mn(IV) oxidation processes, respectively. The one-electron electrochemical oxidation of 2 leads to the mono-mu-oxo mixed-valent species [(mL)Mn(III)-(mu-O)-Mn(IV)(mL)](3+) (2 ox). The UV/Vis spectrum of 2 ox exhibits one large band at 643 nm, which is attributed to the phenolate-->Mn(IV) charge-transfer transition. 2 ox can also be obtained by the direct electrochemical oxidation of 1 in the presence of an external base. The 2 ox and 3 species exhibit a 16-line EPR signal with first peak to last trough widths of 125 and 111 mT, respectively. Both spectra have been simulated by using colinear rhombic Mn-hyperfine tensors. Mechanisms for the chemical formation of 2 and the electrochemical oxidation of 1 into 2 ox are proposed.
Published: 2004
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36. Temperature Dependence of X- and Q-Band EPR Spectra of the Dinuclear Manganese(II) Complex[(NO2Bpmp)Mn2(μ-OAc)2]+: Determination of the Exchange Constant and of the Spin Parameters for theS=1, 2, and 3 Spin States

Author: Guillaume Blain, Martine Nierlich, Eric Rivière, Sebastien Blanchard, and Geneviève Blondin
Subjects: Coupling constant, Spin states, Chemistry, Organic Chemistry, Analytical chemistry, Intermetallic, chemistry.chemical_element, General Chemistry, Manganese, Magnetic susceptibility, Catalysis, Spectral line, law.invention, Crystallography, law, Electron paramagnetic resonance, Spin (physics)
Abstract: A new dinuclear manganese(II) complex was synthesised with the biscompartimental ligand 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-nitrophenol (NO 2 BpmpH) and characterised by X-ray crystallography. Magnetic susceptibility measurements revealed that the two high-spin Mn I I ions are antiferromagnetically coupled with a singlet-to-triplet separation of 7.2 cm - 1 . The powder EPR spectra were recorded for both X- and Q-bands between 1.8 K and 35 K. A detailed analysis of these spectra led to the determination of three out of five individual spin-state zero-field splitting parameters. From the proposed simulations, the exchange coupling constant J and the intermetallic distance have been computed.
Published: 2003
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37. Direct Measurement of the Hyperfine and g-Tensors of a Mn(III)−Mn(IV) Complex in Polycrystalline and Frozen Solution Samples by High-Field EPR

Author: Michèle Cesario, Sun Un, Geneviève Blondin, and Christelle Hureau
Subjects: Analytical chemistry, Biochemistry, Catalysis, law.invention, chemistry.chemical_compound, Colloid and Surface Chemistry, Nuclear magnetic resonance, Biomimetic Materials, law, Freezing, Organometallic Compounds, Electron paramagnetic resonance, Acetonitrile, Anisotropy, Hyperfine structure, Manganese, Valence (chemistry), Electron Spin Resonance Spectroscopy, Matrix isolation, Photosystem II Protein Complex, General Chemistry, Catalase, Ethylenediamines, Magnetic susceptibility, Models, Chemical, chemistry, Crystallization, Ground state
Abstract: The g-tensors and hyperfine tensors of the S = (1)/(2) ground state of the mixed valence [LMn(IIImu-O)(2)Mn(IV)L](3+) complex (L = N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)ethane-1,2-diamine) was deter-mined in the solid-state and frozen acetonitrile solution by high-field EPR. Both samples exhibited complex anisotropic temperature behaviors that precluded the use of routine spectrum simulation procedures to extract the spin parameters. To circumvent this problem, the parameters were measured directly by using multifrequency techniques. In the case of the frozen solution, this approach yielded seven of the nine spin parameters with varying uncertainty, the two extreme principal g-values, the four hyperfine couplings associated with each of these two g-values, and the middle g-value. This latter parameter was obtained from a first moment analysis. Unlike simulations, the statistical errors associated with each value could be assigned in a straightforward and rigorous manner. The directly measured g-values were different in frozen solution and polycrystalline powder. The temperature dependence of the high-field EPR spectra of the polycrystalline powder revealed a spin-spin interaction between the neighboring binuclear complexes.
Published: 2003
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38. X- and Q-Band EPR Studies of the Dinuclear Mn(II) Complex [(Bpmp)Mn2(μ-OAc)2]+. Determination of the Spin Parameters for the S = 1 and S = 2 Spin States

Author: Martine Nierlich, Geneviève Blondin, Eric Rivière, Jean-Jacques Girerd, and Sébastien Blanchard
Subjects: Spin states, Chemistry, Exchange interaction, Analytical chemistry, Magnetic susceptibility, Ion, law.invention, Inorganic Chemistry, Crystallography, Octahedron, law, Antiferromagnetism, Physical and Theoretical Chemistry, Spin (physics), Electron paramagnetic resonance
Abstract: A new mu-phenoxo-bis-mu-acetato di-Mn(II) complex using the BpmpH ligand was isolated as a perchlorate salt (BpmpH = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methyl-phenol). The X-ray structure has been solved showing that the two Mn(II) ions are in a distorted octahedral environment. Investigation of the variation of the molar magnetic susceptibility upon temperature reveals an antiferromagnetic exchange interaction between the two high-spin Mn(II) ions. Fitting of the experimental data led to g = 1.99 and J = 9.6 cm(-1) (H(HDvV) = JS(A).S(B)). EPR spectra recorded on a powder sample of [(Bpmp)Mn(2)(mu-OAc)(2)](ClO(4)).0.5H(2)O at X-band between 4.3 K and room temperature and at Q-band between 5 and 298 K are presented. A new method based on a scrupulous examination of the variation upon temperature of these experimental spectra is developed here to first assign the transitions to the relevant spin states and second to determine the associated spin parameters. This approach is compared to the deconvolution process that has been previously applied to dinuclear Mn(II) complexes or metalloenzyme active sites. Crystallographic data is as follows: triclinic, space group P one macro, a = 10.154(2) A, b = 12.0454(2) A, c = 17.743(4) A, alpha = 101.69(3) degrees, beta = 93.62(3) degrees, gamma = 94.67(3) degrees, Z = 2.
Published: 2003
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39. A Rigid Molecular Scaffold Affixing a (Polypyridine)ruthenium( <scp>II</scp> )‐ and a Nickel( <scp>II</scp> )‐Containing Complex: Spectroscopic Evidence for a Weakly Coupled Bichromophoric System

Author: Geneviève Blondin, Yann Pellegrin, Winfried Leibl, Elodie Anxolabéhère-Mallart, Ally Aukauloo, and Katja E. Berg
Subjects: Quenching (fluorescence), Chemistry, Ligand, Phenazine, chemistry.chemical_element, Conjugated system, Photochemistry, Redox, Ruthenium, law.invention, Inorganic Chemistry, chemistry.chemical_compound, Nickel, Crystallography, law, Electron paramagnetic resonance
Abstract: The synthesis of DppztBuSalH2 (7), a rigid conjugated ditopic ligand containing a Dppz (dipyrido[3,2-a:2′,3′-c]phenazine) skeleton and a salophen-type chelate, is reported. The complexes DppztBuSalNi (10), [Ru(bpy)2(DppztBuSalH2)]2+ (11), and [Ru(bpy)2(DppztBuSalNi)]2+ (12) have been prepared and characterised using common spectroscopic methods. Electrochemical, UV/Vis spectroelectrochemical and EPR studies were conducted on compounds 7, 10, 11, and 12. The singly reduced radical forms of 7 and 10 can be generated electrochemically, with the lone electron located on the low-lying phenazine π*-molecular orbital. Complexes 11 and 12 show several reduction waves and electronic and EPR data obtained for the electrogenerated singly reduced species show them to be closely related to the radical species 7·− and 10·−, respectively. The presence of nickel(II) in compound 12 renders the addition of the second electron on the phenazine group reversible. Both 11 and 12 show common features on the cathodic side of their cyclic voltammograms, with reversible one-electron ruthenium-centred oxidation. An additional low-potential reversible-oxidation wave is observed for 12, and this is ascribed to oxidation of the nickel(II) ion. The combined spectroscopic data best describe the ruthenium-containing complexes as weakly coupled bichromophoric systems. Photophysical studies attest to the formation of a charge-separated state for 11, whereas a strong quenching is detected for 12. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Published: 2003
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40. Synthesis, Structure and Characterisation of New Phenolato-Bridged Manganese Complexes [L2Mn2]2+ − Formation by Ligand Oxidation in LaH [LaH = N-(2-hydroxybenzyl)-N,N′-bis(2-pyridylmethyl)ethane-1,2-diamine]

Author: Martine Nierlich, Elodie Anxolabéhère-Mallart, Geneviève Blondin, Eric Rivière, Christelle Hureau, and Florence Gonnet
Subjects: Coordination sphere, Ligand, Imine, Magnetic susceptibility, law.invention, Inorganic Chemistry, chemistry.chemical_compound, Electron transfer, Crystallography, chemistry, law, Cyclic voltammetry, Acetonitrile, Electron paramagnetic resonance
Abstract: A mononuclear [LaMnIIIOAc](ClO4)·0.5H2O [2(ClO4)·0.5H2O] complex with a new amino-containing pentadentate ligand LaH with a [N4O] coordination sphere has been obtained. Magnetic susceptibility measurements of 2(ClO4)·0.5H2O indicated a high spin electronic configuration for the MnIII ion. In cyclic voltammetry the reversible wave observed at E1/2 = 0.15 V vs. SCE was attributed to the reduction of MnIII into MnII. In acetonitrile solution complex 2 spontaneously evolved into phenolato-bridged MnIIMnII dimeric complexes with the concomitant oxidation of the ligand. X-ray diffraction structures revealed that there is indeed a 1:1 mixture of two closely related complexes: in one case both ligands La− have been oxidised to the imine form leading to the [LiMnIIMnIILi]2+ cation (1a), whereas in the other, only one ligand has been oxidised, leading to the [LaMnIIMnIILi]2+ cation (1b). In both 1a and 1b, MnII ions are in a distorted octahedral environment. Crystallographic data indicated that the Mn2O2 core is similar for 1a and 1b. The complete spectroscopic and electrochemical studies performed on powder samples and on acetonitrile solutions did not allow one to distinguish between the two cations. The magnetic susceptibility measurements performed on a powder sample of 1(BPh4)2·2CH3COCH3 was characteristic of a weak antiferromagnetic coupling interaction between the two high-spin MnII ions (g = 1.95 and J = −1.5 cm−1). Similar behaviour was observed for the powder sample of 1(ClO4)2·H2O (g = 1.96 and J = −2.9 cm−1). Powder samples of 1(BPh4)2·2CH3COCH3 and 1(ClO4)2·H2O showed EPR intensity variations with temperature indicating that the signal was mainly due to the S = 2 spin state. EPR spectra run on the acetonitrile solutions indicated that the dinuclear structure of 1 is maintained. In cyclic voltammetry, complex 1(ClO4)2·H2O exhibited a quasi-reversible wave in oxidation at Ep = 0.71 V vs. SCE, attributed to the slow electron transfer of the MnIIMnII/MnIIMnIII redox process (ksapp = 1.10−4 cm2·s−1). (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
Published: 2002
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41. A New FeMo Complex as a Model of Heterobimetallic Assemblies in Natural Systems: Mössbauer and Density Functional Theory Investigations

Author: Kévin Charreteur, Jean Talarmin, Solène Bouchard, Geneviève Blondin, Philippe Schollhammer, Maurizio Bruschi, Martin Clémancey, Luca De Gioia, Christine Le Roy, François Y. Pétillon, Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO), 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), Laboratoire de Physico-chimie des Métaux en Biologie (LPCMB), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB), Département des Sciences de la Terre et de l'Environnement, Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Bouchard, S, Clémancey, M, Blondin, G, Bruschi, M, Charreteur, K, DE GIOIA, L, Le Roy, C, Pétillon, F, Schollhammer, P, and Talarmin, J
Subjects: Models, Molecular, Iron, chemistry.chemical_element, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, Inorganic Chemistry, Spectroscopy, Mossbauer, Computational chemistry, Mössbauer spectroscopy, Organometallic Compounds, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Group 2 organometallic chemistry, Molybdenum, Hydrogenases, Nitrogenases, Catalysis, Molybdenium, metallic cluster, 010405 organic chemistry, Nitrogenase, 0104 chemical sciences, 3. Good health, chemistry, Quantum Theory, Physical chemistry, Density functional theory
Abstract: International audience; The design of the new FeMo heterobimetallic species [FeMo(CO)(5)(kappa(2)-dppe)(mu-pdt)] is reported. Mossbauer spectroscopy and density functional theory calculations give deep insight into the electronic and structural properties of this compound.
Published: 2014
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42. Cis/Trans Isomerizations in Diiron Complexes Involving Aniline orAnilide Ligands

Author: Ramachandran Balasubramanian, Jean-Marc Latour, Pascale Maldivi, Michaël Carboni, Colette Lebrun, Patrick Dubourdeaux, Eric Gouré, Martin Clémancey, Geneviève Blondin, Pierre-Alain Bayle, Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-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)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)
Subjects: Valence (chemistry), Chemistry, Ligand, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Photochemistry, Medicinal chemistry, Inorganic Chemistry, chemistry.chemical_compound, Aniline, Mössbauer spectroscopy, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Acetonitrile, Triethylamine, Isomerization, Cis–trans isomerism
Abstract: International audience; We have recently reported a deprotonation-induced valence inversion within a phenoxido-bridged mixed-valent diiron(II,III) complex. The initial aniline coordinated to the FeII site reacts with triethylamine, and the resulting complex contains an anilide ligand coordinated to the FeIII ion. The behavior of these complexes in acetonitrile is indeed more intricate. Owing to the very distinctive spectroscopic signatures of the complexes, the conjunction of NMR, Mössbauer, and UV–visible absorption spectroscopies allows one to evidence two isomerization reactions, one involving the aniline linked to FeII and the other the anilide on FeIII. Theoretical calculations sustain this conclusion. Aniline in the cis position versus the bridging phenoxide is shown to be the most stable isomer while the anilide trans to the phenoxido bridge is favored. The trans isomer of the aniline complex is more acidic than the cis one by 1 pKa unit. Isomerization of the anilide complex is 10 times faster than the analogous isomerization of the aniline complex. Both reactions are proposed to proceed through a unique mechanism. This is the first time that such isomerization reactions are evidenced in dinuclear complexes.
Published: 2014
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43. New Systematic Route to Mixed-Valence Triiron Clusters Derived from Dinuclear Models of the Active Site of [Fe–Fe]-Hydrogenases

Author: Philippe Schollhammer, Jean Talarmin, François Y. Pétillon, Geneviève Blondin, Claudio Greco, Martin Clémancey, Laetitia Beaume, Beaume, L, Clémancey, M, Blondin, G, Greco, C, Pétillon, F, Schollhammer, P, Talarmin, J, Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO), 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), Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: hydrogen, iron, Hydrogenase, Valence (chemistry), biology, Hydrogen, 010405 organic chemistry, Chemistry, Organic Chemistry, Inorganic chemistry, Active site, chemistry.chemical_element, 010402 general chemistry, Electrochemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Crystallography, Mössbauer spectroscopy, biology.protein, [CHIM]Chemical Sciences, Propanedithiolate, Direct reaction, Physical and Theoretical Chemistry
Abstract: International audience; A novel reaction pathway to synthesize the linear trinuclear clusters [Fe3(CO)5(κ2-diphosphine)(μ-dithiolate)2] via the direct reaction of the dinuclear hexacarbonyl precursor [Fe2(CO)6(μ-dithiolate)] with the mononuclear species [Fe(CO)2(κ2-diphosphine)(κ2-dithiolate)] has been developed with diphosphine (dppe) and dithiolate (pdt = propanedithiolate) (1) or adtBn ({SCH2}2NBn = azadithiolate) (2). A crystallographic study was carried out on 2 and Mössbauer spectroscopy, and DFT calculations have been used to describe the electronic and structural properties of 1. The electrochemical properties of 1 in the absence and in the presence of a weak acid have been the subject of a preliminary investigation.
Published: 2014
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44. Triggering the generation of an iron(IV)-oxo compound and its reactivity toward sulfides by RuII photocatalysis

Author: 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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45. Synthesis, Structure and Characterization of the New Complex [L1(H2O)Fe(μ-O)Fe(OH2)L1]4+ [L1 =N,N′-Bis(1-methylimidazolyl-2-methyl)-N,N′-Bismethyl-1,2-ethanediamine] − Formation of the (μ-O)(μ-H3O2) Complex upon Deprotonation

Author: Luba Tchertanov, Eric Rivière, Jean Guilhem, Geneviève Chottard, Jean-Jacques Girerd, Sandrine Poussereau, and Geneviève Blondin
Subjects: Inorganic Chemistry, chemistry.chemical_compound, Crystallography, Deprotonation, chemistry, Hydrogen bond, Intramolecular force, Inorganic chemistry, Molecule, Hydroxide, Acetonitrile, Triethylamine, Magnetic susceptibility
Abstract: The compound [L1(H2O)Fe(μ-O)Fe(OH2)L1](ClO4)4·2H2O [1(ClO4)4·2H2O] [L1 = N,N′-bis(1-methylimidazolyl-2-methyl)-N,N′-bismethyl-1,2-ethanediamine] was synthesized. It is characterized by a linear Fe−(μ-O)−Fe motif with an Fe···Fe distance of 3.584(1) A. The measurement of the magnetic susceptibility as a function of temperature indicated a strong antiferromagnetic coupling between the two high-spin FeIII ions (J = −223 cm−1 with H = −J·S1·S2). In the solid state, the symmetric stretching vibration mode of the Fe−(μ-O)−Fe core unit was detected at 347 cm−1, in agreement with a straight Fe−(μ-O)−Fe angle. Upon addition of up to one equivalent of triethylamine to an acetonitrile solution of 1, conversion to the [L1(H2O)Fe(μ-O)Fe(OH)L1]3+ complex 2 was observed. This last species was isolated as a perchlorate salt [2(ClO4)3·H2O]. Susceptibility measurements and Raman and UV/Vis investigations on the powder and/or an acetonitrile solution confirmed the presence of an intramolecular hydrogen bond between the coordinated water molecule and the hydroxide group leading to a bent [Fe(μ-O)Fe]4+ core structure.
Published: 2001
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46. Mononuclear Fe(II) and Fe(III) complexes with the tetradentate ligand N,N′-bisbenzyl-N,N′-bis(2-pyridylmethyl)-ethane-1,2-diamine. Synthesis and characterisation

Author: Jean Guilhem, Dirk Defaye, Christian Philouze, Luba Tchertanov, Jean-Jacques Girerd, Geneviève Blondin, Sandrine Poussereau, and Jalila Ariane Simaan
Subjects: Spin states, Chemistry, Ligand, Inorganic chemistry, Crystal structure, law.invention, Inorganic Chemistry, Bond length, Crystallography, chemistry.chemical_compound, Oxidation state, law, Diamine, Pyridine, Materials Chemistry, Physical and Theoretical Chemistry, Electron paramagnetic resonance
Abstract: Two new mononuclear iron complexes, [(LBzl2)Fe(II)Cl2]·H2O and [(LBzl2) Fe(III)Cl2]·PF6, (LBzl2=N,N′-bisbenzyl-N,N′-bis(2-pyridylmethyl)-ethane-1,2-diamine) have been synthesised in view of generating complexes to mimic the active site of methane monooxygenase. Their structures have been determined by X-ray analysis. In both species, the iron atom shows a pseudo-octahedral coordination with two pyridine nitrogen atoms in axial positions and two amine nitrogen atoms in the equatorial plane. Two other equatorial positions are occupied by chloride ions. The coordination bond lengths clearly indicate the sensitivity of the ligand to the oxidation state of the iron. Thus, the FeN and FeCl bond distances in Fe(II) complex are more elongated than corresponding distances in Fe(III). A statistical examination of the bond distances of hexacoordinated Fe(II) and Fe(III) complexes using the Cambridge Structural Database provides evidence to relate both complexes to their spin state. The redox potential of the Fe(III)/Fe(II) couple was determined by cyclic voltammetry. The UV–Vis spectra are dominated by charge transfer transitions. The X-band EPR spectrum of [(LBzl2) FeCl2]·PF6 is characteristic of an S=5/2 species with an unusual zero-field splitting.
Published: 2000
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47. SQUID Magnetization Study of the Infrared-Induced Spin Transition in the S2 State of Photosystem II: Spin Value Associated with the g = 4.1 EPR Signal

Author: Sun Un, A. William Rutherford, † and Jean-Jacques Girerd, Geneviève Blondin, Olivier Horner, Eric Rivière, and Alain Boussac
Subjects: Photosystem II, Chemistry, Infrared, Analytical chemistry, Spin transition, General Chemistry, Biochemistry, Signal, Redox, Catalysis, law.invention, Magnetization, Colloid and Surface Chemistry, law, Electron paramagnetic resonance, Spin (physics)
Abstract: The Mn4 complex which is involved in water oxidation in photosystem II is known to exhibit three types of EPR signals in the S2 state, one of the five redox states of the enzyme cycle: a multiline signal (spin 1/2), signals at g > 5 (spin 5/2), and a signal at g = 4.1 (spin value 3/2 or 5/2). The multiline and g = 4.1 signals are those the most readily observed. The relative proportions of the g = 4.1 signal and of the multiline signal are affected by many biochemical treatments including the substitution of Ca2+and Cl- which are two essential cofactors for O2 evolution. The state responsible for the multiline signal can also be converted, reversibly, to that responsible for the g = 4.1 signal upon the absorption of near-IR light at around 150 K. These infrared-induced effects are confined to the Mn4 cluster, and no other redox change occurs in the enzyme. Here, we have used the IR-induced photochemistry of the Mn4 cluster to measure the changes in magnetization occurring upon interconversion of the stat...
Published: 1998
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48. Synthesis, Structure, and Characterization of the New [L(OH)Fe(μ-O)Fe(OH2)L]3+ Complex (L = N,N‘-Dimethyl-N,N‘-bis(2-pyridylmethyl)ethane-1,2-diamine). Detection of an Equilibrium with the Protonated Diamond Form [LFe(μ-O)(μ-OH)FeL]3+ in Acetonitrile

Author: Jean Guilhem, Sandrine Poussereau, Geneviève Blondin, Michèle Cesario, Geneviève Chottard, Florence Gonnet, and Jean-Jacques Girerd
Subjects: Chemistry, Diamond, Protonation, engineering.material, Magnetic susceptibility, Ion, Inorganic Chemistry, Crystallography, chemistry.chemical_compound, Diamine, engineering, Orthorhombic crystal system, Physical and Theoretical Chemistry, Acetonitrile, Dissolution
Abstract: The complex [L(H2O)Fe(μ-O)Fe(OH)L](ClO4)3·H2O, where L = N,N‘-dimethyl-N,N‘-bis(2-pyridylmethyl)ethane-1,2-diamine, was synthesized. It crystallizes in the orthorhombic space group P212121 with a = 13.283(5) A, b = 16.050(9) A, c = 20.050(9) A, V = 4476(6) A3, and Z = 4. It presents the hydrogen-bonded [(H2O)Fe(μ-O)Fe(OH)]3+ core unit characterized by an Fe−O−Fe angle of 137.5(2)° and an Fe−Fe distance of 3.396(1) A. The measurement of the magnetic susceptibility as a function of the temperature indicated an antiferromagnetic coupling between the two high-spin Fe(III) ions J = −184 cm-1 (H = −JS1·S2). In the solid state the symmetric stretching vibration was observed at 438 cm-1. Upon dissolution in dry acetonitrile, this vibration was no longer detected and an intense band was observed at 600 cm-1. This frequency can be correlated with an Fe−O−Fe angle of 111°. This value suggests that the species which exists in these conditions is the protonated diamond core [Fe(μ-O)(μ-OH)Fe]3+, analogous to that ident...
Published: 1998
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49. Structure and electronic properties of (N,N′-bis(4-methyl-6-tert-butyl-2-methyl-phenolato)-N,N′-bismethyl-1,2-diaminoethaneFeIII (DBSQ). Spectroelectrochemical study of the red-ox properties. Relevance to intradiol catechol dioxygenases

Author: Emile L. Bominaar, Natarajan Ravi, Eckart Münck, Michèle Cesario, Alexander Nivorojkine, Elodie Anxolabéhère-Mallart, Jean Guilhem, Lyuba Tchertanova, Geneviève Blondin, Jean-Jacques Girerd, and Pierre Mialane
Subjects: Chemistry, Stereochemistry, Dioxygenase activity, Crystal structure, Square pyramidal molecular geometry, law.invention, Marcus theory, Inorganic Chemistry, Electron transfer, Crystallography, Deprotonation, Oxidation state, law, Materials Chemistry, Physical and Theoretical Chemistry, Electron paramagnetic resonance
Abstract: The species LFe III Cl ( 1 ) was synthesized where L 2− is the dianion N , N ′-bis(4-methyl-6-tert-butyl-2-methyl-phenolato)- N , N ′-bismethyl1,2-diaminoethane. It crystallizes in the triclinic space group P -1 with a = 14.704(6), b = 17.421(7), c = 17.328(8) A , α = 89.45(8) , β = 129.76(9), γ = 102.71(9)°, V = 3277(2) A 3 and Z = 2 . The molecule has approximately a square pyramidal structure. In the presence of DBCH 2 (3,5-di-tert-butylcatechol), this complex gives LFe III (DBSQ) ( 2 ), a stable Fe(III)-semiquinonato complex (DBSQ − stands for the 3,5-di-tert-butyl- o -benzosemiquinone monoanion). It crystallizes in the monoclinic space group C 2/ c with a = 36.24(2), b = 10.438(5), c = 23.928(12) A , β = 115.31(5)°, V = 8183(7) A 3 and Z = 8 . This X-ray study allows the structure of the DBSQ − monoanion complexed to Fe(III) to be compared with that of the DBC 2− dianion complexed to Fe(III) as found in several complexes already described (see for instance H.G. Jang, D.D. Cox and L. Que, Jr., J. Am. Chem. Soc., 113 (1991) 9200–9204). A clear alternation is found in CC bond lengths in the DBSQ − monoanion. Magnetic coupling between the S Fe = 5 2 electronic spin on Fe(III) and the S R = 1 2 electronic spin on the DBSQ − anion radical has been deduced from the behavior of the magnetic susceptibility as a function of temperature. It has been found antiferromagnetic with J = −206 cm −1 (with the notation H = − JS Fc S R ). This is a weaker coupling than that found in other analogous complexes. Mossbauer spectroscopy confirms the S = 2 nature of the ground state. Analysis of the 57 Fe hyperfine coupling parameters prove that the earlier description of the electronic structure of 2 is correct. It is possible to reduce 2 to get [LFe III (DBC)] − ( E 0 = −0.3 V/SCE in AcN). This species has UV-Vis and EPR properties typical of this type of complex. In the absence of protons, [LFe III (DBC)] − is stable under pure O 2 but the addition of protons results in its oxidation to form 2 . The insensitivity of [LFe III (DBC)] − to O 2 is compatible with the idea that the system has to go through an Fe(II) (DBSQ) form by internal electron transfer to allow the attack of the aromatic ring by O 2 (see L. Que and R.Y.N. Ho, Chem. Rev., 96 (1996) 2607–2624, for a review). Observation of the lowest energy LMCT band in [LFe III (DBC)] − at 620 nm (2.00 eV, AcN) suggests that the Fe(II) (DBSQ) form is indeed at high energy ( ΔG 0 ) above the catechol form. This contributes from Marcus theory to a high activation energy. In intradiol dioxygenases the decoordination of one of the tyrosine ligands (D.H. Ohlendorf, A.M. Orville and J.D. Lipscomb, J. Mol. Biol., 244 (1994) 586–608) is certainly important for the deprotonation of the catechol substrate but could also accelerate the formation of the postulated Fe(II)-semiquinonato intermediate. The stability of 2 under O 2 also demonstrates the importance of the Fe(II) oxidation state in order to lead to a peroxo form of the oxygen adduct. The insensitivity of [LFe III (DBC)] − to O 2 argues against the view of the dioxygenase activity as the result of an electrophilic attack of the catecholato by O 2 in model complexes.
Published: 1997
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50. Electron paramagnetic resonance study of the S = ½ ground state of a radiolysis-generated manganese(III)–trimanganese(IV) form of [MnIV4O6(bipy)6]4+ (bipy = 2,2′-bipyridine). Comparison with the photosynthetic Oxygen Evolving Complex †

Author: Stenbjörn Styring, Jean-Jacques Girerd, Alain Boussac, Christian Philouze, Geneviève Blondin, Roman Davydov, Marie-France Charlot, and Björn Åkermark
Subjects: chemistry.chemical_element, General Chemistry, Manganese, Oxygen-evolving complex, Photochemistry, 2,2'-Bipyridine, law.invention, chemistry.chemical_compound, Bipyridine, Crystallography, chemistry, law, Radiolysis, Electron paramagnetic resonance, Ground state, Hyperfine structure
Abstract: gamma-Ray irradiation at liquid nitrogen temperature of a dimethylformamide solution of the tetranuclear complex [(Mn4O6)-O-IV(bipy)(6)](4+) (bipy = 2,2'-bipyridine) allowed the generation of the first mixed-valence tetranuclear system containing Mn-III and Mn-IV ions and exhibiting a S = 1/2 ground state. The X-band EPR spectrum of this tetranuclear system has been obtained. Simulations have been undertaken and the Mn hyperfine coupling tensors determined clearly show a (MnMn3IV)-Mn-III, composition for the EPR active species. A general approach for the analysis of the isotropic components of the Mn hyperfine tensors is presented in detail. This allowed the determination of the spin projection value for each Mn site. A three J coupling scheme assuming that the linear topology of the starting compound remains is able to reproduce these spin projection values if and only if the Mn-III ion is located at a terminal position in a N4O2 environment. The EPR signal of this [Mn4O6(bipy)(6)](3+) species is compared with the multiline signal observed in the S-2 state of the photosynthetic Oxygen Evolving Complex.
Published: 1997
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