Author: "Winfried Leibl" - Searchworks@Jio Institute Digital Library Search Results

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130 results on '"Winfried Leibl"'

1. Unlocking full and fast conversion in photocatalytic carbon dioxide reduction for applications in radio-carbonylation

Author: Serena Monticelli, Alex Talbot, Philipp Gotico, Fabien Caillé, Olivier Loreau, Antonio Del Vecchio, Augustin Malandain, Antoine Sallustrau, Winfried Leibl, Ally Aukauloo, Frédéric Taran, Zakaria Halime, and Davide Audisio
Subjects: Science
Abstract: Abstract Harvesting sunlight to drive carbon dioxide (CO2) valorisation represents an ideal concept to support a sustainable and carbon-neutral economy. While the photochemical reduction of CO2 to carbon monoxide (CO) has emerged as a hot research topic, the full CO2-to-CO conversion remains an often-overlooked criterion that prevents a productive and direct valorisation of CO into high-value-added chemicals. Herein, we report a photocatalytic process that unlocks full and fast CO2-to-CO conversion (
Published: 2023
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2. Tracking light-induced electron transfer toward O2 in a hybrid photoredox-laccase system

Author: Rajaa Farran, Yasmina Mekmouche, Nhat Tam Vo, Christian Herrero, Annamaria Quaranta, Marie Sircoglou, Frédéric Banse, Pierre Rousselot-Pailley, A. Jalila Simaan, Ally Aukauloo, Thierry Tron, and Winfried Leibl
Subjects: Chemistry, Catalysis, Biomolecules, Science
Abstract: Summary: Photobiocatalysis uses light to perform specific chemical transformations in a selective and efficient way. The intention is to couple a photoredox cycle with an enzyme performing multielectronic catalytic activities. Laccase, a robust multicopper oxidase, can be envisioned to use dioxygen as a clean electron sink when coupled to an oxidation photocatalyst. Here, we provide a detailed study of the coupling of a [Ru(bpy)3]2+ photosensitizer to laccase. We demonstrate that efficient laccase reduction requires an electron relay like methyl viologen. In the presence of dioxygen, electrons transiently stored in superoxide ions are scavenged by laccase to form water instead of H2O2. The net result is the photo accumulation of highly oxidizing [Ru(bpy)3]3+. This study provides ground for the use of laccase in tandem with a light-driven oxidative process and O2 as one-electron transfer relay and as four-electron substrate to be a sustainable final electron acceptor in a photocatalytic process.
Published: 2021
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3. Back Cover: Bio‐Inspired Bimetallic Cooperativity Through a Hydrogen Bonding Spacer in CO 2 Reduction (Angew. Chem. Int. Ed. 8/2023)

Author: CHANJUAN ZHANG, Ally Aukauloo, Philipp Gotico, Diana Dragoe, Winfried Leibl, Zakaria Halime, and Régis Guillot
Subjects: General Chemistry, Catalysis
Published: 2023
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4. Bio‐Inspired Bimetallic Cooperativity Through a Hydrogen Bonding Spacer in CO 2 Reduction

Author: CHANJUAN ZHANG, Ally Aukauloo, Philipp Gotico, Diana Dragoe, Winfried Leibl, Zakaria Halime, and Régis Guillot
Subjects: General Medicine, General Chemistry, Catalysis
Abstract: At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate the interconversion between CO2 and CO. We have designed a molecular catalyst implementing a bimetallic iron complex with an embarked second coordination sphere with multi-point hydrogen-bonding interactions. We found that, when immobilized on carbon paper electrode, the dinuclear catalyst enhances up to four fold the heterogeneous CO2 reduction to CO in water with an improved selectivity and stability compared to the mononuclear analogue. Interestingly, quasi-identical catalytic performances are obtained when one of the two iron centers was replaced by a redox inactive Zn metal, questioning the cooperative action of the two metals. Snapshots of X-ray structures indicate that the two metalloporphyrin units tethered by a urea group is a good compromise between rigidity and flexibility to accommodate CO2 capture, activation, and reduction.
Published: 2023
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5. Photocatalytic generation of a non-heme Fe(III)-hydroperoxo species with O$_2$ in water for oxygen atom transfer reaction

Author: Eva Pugliese, Nhat Tam Vo, Alain Boussac, Frédéric Banse, Yasmina Mekmouche, Jalila Simaan, Thierry Tron, Philipp Gotico, Marie Sircoglou, Zakaria Halime, Winfried Leibl, 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), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019)
Subjects: [CHIM]Chemical Sciences, General Chemistry
Abstract: International audience; Coupling a photoredox module and a bio-inspired non-heme model to activate O$_2$ for oxygen atom transfer (OAT) reaction requires a vigorous investigation to shed light on the multiple competing electron transfer steps, charge accumulation and annihilation processes, and the activation of O$_2$ at the catalytic unit. We found that the efficient oxidative quenching mechanism between [Ru(bpy)$_3$]$^{2+}$ chromophore and a reversible electron mediator, methyl viologen (MV$^{2+}$), to form the reducing species methyl viologen radical (MV$^{•+}$) can convey an electron to O$_2$ to form the uperoxide radical and resetting an Fe(III) species in a catalytic cycle to the Fe(II) state in an aqueous solution. The formation of the Fe(III)-hydroperoxo (Fe$^{III}$ OOH) intermediate therefrom to evolve to highly oxidized iron-oxo species to perform the OAT reaction to an alkene substrate. Such a strategy allows to bypass the challenging task of charge accumulation at the molecular catalytic unit for the two-electron activation of O$_2$. The Fe$^{III}$-OOH catalytic precursor was trapped and characterized by EPR spectroscopy pertaining a metal assisted catalysis. Importantly, we found that the substrate itself can act as the electron donor to reset the photooxidzed chromophore in the initial state closing the photocatalytic loop hence excluding the use of a sacrificial electron donor. Laser Flash Photolysis (LFP) studies and spectroscopic monitoring during photocatalysis lend credence to the proposed catalytic cycle.
Published: 2022
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6. Identification of a Ubiquinone–Ubiquinol Quinhydrone Complex in Bacterial Photosynthetic Membranes and Isolated Reaction Centers by Time-Resolved Infrared Spectroscopy

Author: Alberto Mezzetti, Jean-François Paul, Winfried Leibl, 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), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, Laboratoire de Réactivité de Surface [LRS], Institut de Biologie Intégrative de la Cellule [I2BC], and Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Subjects: rapid-scan FTIR, Organic Chemistry, ubiquinol, bacterial reaction center (RC), General Medicine, quinhydrone, ubiquinone, charge-transfer complex, Fourier Transform Infrared (FTIR) difference spectroscopy, chromatophores, Rhodobacter (Rb.) sphaeroides, Catalysis, Computer Science Applications, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Inorganic Chemistry, Physical and Theoretical Chemistry, Molecular Biology, Spectroscopy
Abstract: International audience; Ubiquinone redox chemistry is of fundamental importance in biochemistry, notably in bioenergetics. The bi-electronic reduction of ubiquinone to ubiquinol has been widely studied, including by Fourier transform infrared (FTIR) difference spectroscopy, in several systems. In this paper, we have recorded static and time-resolved FTIR difference spectra reflecting light-induced ubiquinone reduction to ubiquinol in bacterial photosynthetic membranes and in detergent-isolated photosynthetic bacterial reaction centers. We found compelling evidence that in both systems under strong light illumination—and also in detergent-isolated reaction centers after two saturating flashes—a ubiquinone–ubiquinol charge-transfer quinhydrone complex, characterized by a characteristic band at ~1565 cm−1, can be formed. Quantum chemistry calculations confirmed that such a band is due to formation of a quinhydrone complex. We propose that the formation of such a complex takes place when Q and QH2 are forced, by spatial constraints, to share a common limited space as, for instance, in detergent micelles, or when an incoming quinone from the pool meets, in the channel for quinone/quinol exchange at the QB site, a quinol coming out. This latter situation can take place both in isolated and membrane bound reaction centers Possible consequences of the formation of this charge-transfer complex under physiological conditions are discussed.
Published: 2023
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7. Heterolytic O-O Bond Cleavage Upon Single Electron Transfer to a Nonheme Fe(III)-OOH Complex

Author: Antoine Bohn, Katell Sénéchal‐David, Jean‐Noël Rebilly, Christian Herrero, Winfried Leibl, Elodie Anxolabéhère‐Mallart, Frédéric Banse, 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), Laboratoire d'Electrochimie Moléculaire (LEM (UMR_7591)), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011)
Subjects: Oxygen, Reducing Agents, Iron, Organic Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Electrons, General Chemistry, Ferrous Compounds, Ferric Compounds, Catalysis
Abstract: International audience; The one-electron reduction of the nonheme iron(III)-hydroperoxo complex, [Fe$^{III}$(OOH)(L$_5$$^2$)]$^{2+}$ (L$_5$$^2$=N-methyl-N,N’,N’-tris(2-pyridylmethyl)ethane-1,2-diamine), carried out at −70 °C results in the release of dioxygen and in the formation of [Fe$^{II}$(OH)(L$_5$$^2$)]$^+$ following a bimolecular process. This reaction can be performed either with cobaltocene as chemical reductant, or electrochemically. These experimental observations are consistent with the disproportionation of the hydroperoxo group in the putative Fe$^{II}$(OOH) intermediate generated upon reduction of the Fe$^{III}$(OOH) starting complex. One plausible mechanistic scenario is that this disproportionation reaction follows an O−O heterolytic cleavage pathway via a Fe$^{IV}$-oxo species
Published: 2022
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8. Cover Picture: Dissection of Light‐Induced Charge Accumulation at a Highly Active Iron Porphyrin: Insights in the Photocatalytic CO 2 Reduction (Angew. Chem. Int. Ed. 14/2022)

Author: Eva Pugliese, Philipp Gotico, Iris Wehrung, Bernard Boitrel, Annamaria Quaranta, Minh‐Huong Ha‐Thi, Thomas Pino, Marie Sircoglou, Winfried Leibl, Zakaria Halime, and Ally Aukauloo
Subjects: General Chemistry, Catalysis
Published: 2022
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9. Titelbild: Dissection of Light‐Induced Charge Accumulation at a Highly Active Iron Porphyrin: Insights in the Photocatalytic CO 2 Reduction (Angew. Chem. 14/2022)

Author: Eva Pugliese, Philipp Gotico, Iris Wehrung, Bernard Boitrel, Annamaria Quaranta, Minh‐Huong Ha‐Thi, Thomas Pino, Marie Sircoglou, Winfried Leibl, Zakaria Halime, and Ally Aukauloo
Subjects: General Medicine
Published: 2022
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10. Dissection of light-induced charge accumulation at a highly active iron porphyrin: insights in the photocatalytic CO$_2$ reduction

Author: Eva Pugliese, Philipp Gotico, Iris Wehrung, Bernard Boitrel, Annamaria Quaranta, Minh‐Huong Ha‐Thi, Thomas Pino, Marie Sircoglou, Winfried Leibl, Zakaria Halime, Ally Aukauloo, Université Paris-Saclay, 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 des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-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), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Grand Équipement National De Calcul Intensif. Grant Number: A0070810977, Institut universitaire de France, ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019), and ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011)
Subjects: Photo-Reduction, Porphyrins, Iron, [CHIM]Chemical Sciences, General Chemistry, General Medicine, Mechanism, Carbon Dioxide, Catalysis
Abstract: International audience; Iron porphyrins are among the best molecular catalysts for the electrocatalytic CO$_2$ reduction reaction. Powering these catalysts with the help of photosensitizers comes along with a couple of unsolved challenges that need to be addressed with much vigor. We have designed an iron porphyrin catalyst decorated with urea functions (UrFe) acting as a multipoint hydrogen bonding scaffold towards the CO$_2$ substrate. We found a spectacular photocatalytic activity reaching unreported TONs and TOFs as high as 7270 and 3720 h$^{-1}$ , respectively. While the Fe$^0$ redox state has been widely accepted as the catalytically active species, we show here that the Fe(I) species is already involved in the CO$_2$ activation, which represents the rate-determining step in the photocatalytic cycle. The urea functions help to dock the CO$_2$ upon photocatalysis. DFT calculations bring support to our experimental findings that constitute a new paradigm in the catalytic reduction of CO$_2$
Published: 2022
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11. Dissection of Light-Induced Charge Accumulation at a Highly Active Iron Porphyrin: Insights in the Photocatalytic CO

Author: Eva, Pugliese, Philipp, Gotico, Iris, Wehrung, Bernard, Boitrel, Annamaria, Quaranta, Minh-Huong, Ha-Thi, Thomas, Pino, Marie, Sircoglou, Winfried, Leibl, Zakaria, Halime, and Ally, Aukauloo
Abstract: Iron porphyrins are among the best molecular catalysts for the electrocatalytic CO
Published: 2021

12. 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

13. 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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14. Proton-controlled Action of an Imidazole as Electron Relay in a Photoredox Triad

Author: Philipp Gotico, Christian Herrero, Stefano Protti, Annamaria Quaranta, Sujitraj Sheth, Reza Fallahpour, Rajaa Farran, Zakaria Halime, Marie Sircoglou, Ally Aukauloo, Winfried Leibl, 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 Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Pavia = University of Pavia (UNIPV), and Universität Zürich [Zürich] = University of Zurich (UZH)
Subjects: Electron Transport, Light, Imidazoles, [CHIM]Chemical Sciences, Electrons, Physical and Theoretical Chemistry, Protons
Abstract: Electron relays play a crucial role for efficient light-induced activation by a photo-redox moiety of catalysts for multi-electronic transformations. Their insertion between the two units reduces detrimental energy transfer quenching while establishing at the same time unidirectional electron flow. This rectifying function allows charge accumulation necessary for catalysis. Mapping these events in photophysical studies is an important step towards the development of efficient molecular photocatalysts. Three modular complexes comprised of a Ru-chromophore, an imidazole electron relay function, and a terpyridine unit as coordination site for a metal ion were synthesized and the light-induced electron transfer events studied by laser flash photolysis. In all cases, formation of an imidazole radical by internal electron transfer to the oxidized chromophore was observed. The effect of added base evidenced that the reaction sequence depends strongly on the possibility for deprotonation of the imidazole function in a proton-coupled electron transfer process. In the complex with Mn
Published: 2021
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15. Tracking light-induced electron transfer toward O2 in a hybrid photoredox-laccase system

Author: Yasmina Mekmouche, Thierry Tron, Ally Aukauloo, Marie Sircoglou, Pierre Rousselot-Pailley, Christian Herrero, Annamaria Quaranta, Nhat Tam Vo, Frédéric Banse, A. Jalila Simaan, Winfried Leibl, Rajaa Farran, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Universite Paris-Saclay, 91198 ´ Gif-sur-Yvette, France, Lebanese International University (LIU), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0301 basic medicine, Science, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Multicopper oxidase, Photochemistry, Article, Catalysis, 03 medical and health sciences, Electron transfer, Oxidizing agent, ComputingMilieux_MISCELLANEOUS, Laccase, chemistry.chemical_classification, Biomolecules, Multidisciplinary, Chemistry, Substrate (chemistry), Electron acceptor, 021001 nanoscience & nanotechnology, 3. Good health, 030104 developmental biology, Photocatalysis, 0210 nano-technology
Abstract: Summary Photobiocatalysis uses light to perform specific chemical transformations in a selective and efficient way. The intention is to couple a photoredox cycle with an enzyme performing multielectronic catalytic activities. Laccase, a robust multicopper oxidase, can be envisioned to use dioxygen as a clean electron sink when coupled to an oxidation photocatalyst. Here, we provide a detailed study of the coupling of a [Ru(bpy)3]2+ photosensitizer to laccase. We demonstrate that efficient laccase reduction requires an electron relay like methyl viologen. In the presence of dioxygen, electrons transiently stored in superoxide ions are scavenged by laccase to form water instead of H2O2. The net result is the photo accumulation of highly oxidizing [Ru(bpy)3]3+. This study provides ground for the use of laccase in tandem with a light-driven oxidative process and O2 as one-electron transfer relay and as four-electron substrate to be a sustainable final electron acceptor in a photocatalytic process., Graphical abstract, Highlights • An electron relay boosts photoreduction of laccase • Superoxide is efficiently captured by laccase preventing formation of H2O2 • Light activation reveals information on elementary steps inside the enzyme • Laccase enables O2 as terminal electron acceptor for oxidative photocatalysis, Chemistry ; Catalysis ; Biomolecules
Published: 2021
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16. Second-sphere hydrogen-bonding enhances heterogeneous electrocatalytic CO 2 to CO reduction by iron porphyrins in water

Author: Zakaria Halime, François Brisset, Winfried Leibl, Ally Aukauloo, Benedikt Lassalle-Kaiser, Bernard Boitrel, Chanjuan Zhang, Diana Dragoe, 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 des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Synchrotron SOLEIL (SSOLEIL), 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), This work has been supported by the French National Research Agency (LOCO, grant no. ANR-19-CE05-0020-02 and LABEX CHARMMMAT, grant no. ANR-11-LABX-0039). We thank the CNRS, CEA Saclay, ICMMO and the University of Paris-Saclay for their financial support. We thank the China Scholarship Council for supporting C. Zhang (CSC student number 201904910525). We also thank the analytical support facility at ICMMO for their help with the XPS and TEM analysis., ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011), ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Hydrogen bond, Chemistry, Carbon nanotube, 010402 general chemistry, Heterogeneous catalysis, 01 natural sciences, Pollution, 0104 chemical sciences, law.invention, Catalysis, Chemical engineering, 13. Climate action, law, Electrode, Environmental Chemistry, [CHIM]Chemical Sciences, Selective reduction, Selectivity, Chemically modified electrode
Abstract: International audience; Intense efforts are currently being devoted to discovering cost-effective catalysts for the selective reduction of carbon dioxide (CO2). Many advances have indeed been achieved in the design of molecular complexes containing second coordination chemical functionalities that have contributed to boosting the homogeneous electrocatalytic activity. The introduction of such chemical facets in heterogeneous catalysis is still lacking. Here, we report the electrocatalytic properties of a chemically modified electrode with a molecular iron-porphyrin catalyst holding urea functions (UrFe) in CO2 reduction, acting as a multipoint hydrogen bonding cleft to enhance CO2 binding. The immobilization of UrFe on multiwall carbon nanotubes (MWCNTs)/carbon paper (CP) allows the investigation of the catalytic performance in water. We found, herein, that the modified electrode displays excellent selectivity towards CO production in water, which is also acting as the sole proton source. Importantly, we observed one of the highest effective turnover frequency (eTOF) values (>21 s−1) at a potential of −0.78 V vs. RHE in comparison with similar modified electrode containing bare iron-porphyrin analogues. Our results therefore point to a remarkable gain in electrocatalytic performance of molecular catalysts at the surface of the electrodes with the added dimensionality of chemical functions operating as molecular clefts towards the binding and reduction of CO2.
Published: 2021
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17. Tracking Charge Accumulation in a Functional Triazole‐Linked Ruthenium‐Rhenium Dyad Towards Photocatalytic Carbon Dioxide Reduction

Author: Thu-Trang Tran, Boris Vauzeilles, Zakaria Halime, Christophe Lefumeux, Ally Aukauloo, Aurélie Baron, Philipp Gotico, Winfried Leibl, Thomas Pino, Annamaria Quaranta, Minh-Huong Ha-Thi, Institut des Sciences Moléculaires d'Orsay (ISMO), 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), Institut de Chimie des Substances Naturelles (ICSN), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), and ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019)
Subjects: 010405 organic chemistry, Organic Chemistry, Supramolecular chemistry, Triazole, chemistry.chemical_element, [CHIM.CATA]Chemical Sciences/Catalysis, Rhenium, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Analytical Chemistry, Ruthenium, chemistry.chemical_compound, Electron transfer, chemistry, 13. Climate action, Carbon dioxide, Photocatalysis, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Electrochemical reduction of carbon dioxide
Abstract: International audience; The [Re(bpy)(CO)3Cl] catalyst pioneered by Lehn for the two-electron reduction of CO2 has constantly revealed unique facets in the mechanistic understanding of the selective transformation of CO2. A novel triazole-linked ruthenium photosensitizer and a rhenium catalyst dyad was synthesized and investigated for photo-induced charge accumulation using time-resolved absorption spectroscopy. The triazole bridging ligand promoted weak electronic communication between the two units, resulting in an anodic shift of the reduction potentials of the Re moiety. Upon excitation of the photosensitizer, the first reduction of the catalyst occurred with a fast apparent rate of >5×107 s−1. Using a double-excitation nanosecond pump-pump-probe setup to track the second electron accumulation on the catalytic unit was not conclusive as no observable absorption changes occurred upon the second excitation, suggesting a pathway for an efficient intramolecular reverse electron transfer preventing the two-electron accumulation at the catalyst under our experimental conditions. Nevertheless, under continuous irradiation and with the use of sacrificial electron donors, photocatalytic CO2 reduction assays showed good turnover numbers, hinting at the non-innocent role of byproducts in solution.
Published: 2021
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18. Through‐Space Electrostatic Interactions Surpass Classical Through‐Bond Electronic Effects in Enhancing CO 2 Reduction Performance of Iron Porphyrins

Author: Zakaria Halime, Winfried Leibl, Asma Khadhraoui, Ally Aukauloo, Philipp Gotico, 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), and ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019)
Subjects: Coordination sphere, biology, Chemistry, General Chemical Engineering, 02 engineering and technology, [CHIM.CATA]Chemical Sciences/Catalysis, Orders of magnitude (numbers), Overpotential, 010402 general chemistry, 021001 nanoscience & nanotechnology, biology.organism_classification, Electrostatics, Electrocatalyst, 01 natural sciences, 0104 chemical sciences, Catalysis, General Energy, Computational chemistry, Electronic effect, Environmental Chemistry, Tetra, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, 0210 nano-technology
Abstract: International audience; In his pioneering work to unravel the catalytic power of enzymes, A. Warshel has pertinently validated that electrostatic interactions play a major role in the activation (bond making and breaking) of substrates. Implementing such chemical artifice in bio-inspired molecular-based catalysts may help in improving their catalytic properties. In this study, we have designed a series of tetra-, di-and mono-substituted iron porphyrins with cationic imidazolium functions. The presence of a cationic module in the second coordination sphere could help to stabilize the [Fe-CO2] intermediate upon electrocatalysis through an electrostatic interaction. We found herein that the overpotential of these catalysts is a function of the number of embarked imidazolium units ranging from 230 to 620 mV compared to 680 mV for the parent nonfunctionalized tetra-phenyl iron porphyrin. Importantly, we evidenced a gain of six orders of magnitude for the turnover frequencies going from the tetra-to the mono-substituted catalyst. The comparative study nails the fact that the electrocatalytic performance trend of through-space electrostatic interaction models outperforms the classic throughstructure electronic effect strategy. Henceforth, including controlled topological electrostatic interaction may be an invaluable chemical tool in the design of molecular catalysts in the activation of small molecules.
Published: 2021
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19. Tracking Light-Induced Electron Transfer Towards O 2 in a Hybrid Photoredox-Laccase System

Author: Nhat Tam Vo, Marie Sircoglou, Pierre Rousselot-Pailley, Yasmina Mekmouche, A. Jalila Simaan, Christian Herrero, Ally Aukauloo, Winfried Leibl, Thierry Tron, Annamaria Quaranta, Rajaa Farran, and Frédéric Banse
Subjects: Laccase, chemistry.chemical_classification, Electron transfer, Chemistry, Oxidizing agent, Photocatalysis, Substrate (chemistry), Electron acceptor, Multicopper oxidase, Photochemistry, Catalysis
Abstract: Photobiocatalysis is an interesting approach to use light to perform specific chemical transformations in a selective and efficient way. The intention is to couple a photoredox cycle with an enzyme performing multielectronic catalytic activity. Laccase, a robust multicopper oxidase, can be envisioned as a tool to use dioxygen as a clean electron sink when coupled to an oxidation photocatalyst. Here, we provide a detailed study of the coupling of a [Ru(bpy)3]2+ photosensitizer to laccase. We demonstrate that efficient laccase reduction requires using an electron relay like methyl viologen. In the presence of dioxygen, electrons transiently stored in superoxide ions (O2●–) are scavenged by laccase leading to formation of water instead of H2O2. The net result is the photo accumulation, in an essentially irreversible way, of highly oxidizing [Ru(bpy)3]3+. This study provides a global scheme for the future use of laccase, in tandem with a light-driven oxidative process, using O2 as both a one-electron transfer relay and a 4-electron substrate to become the sustainable final electron acceptor in a such a hybrid photocatalytic process.
Published: 2021
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20. Imbroglio at a photoredox-iron-porphyrin catalyst dyad for the photocatalytic CO 2 reduction

Author: Winfried Leibl, Ally Aukauloo, Minh-Huong Ha-Thi, Athanassios G. Coutsolelos, Georgios Charalambidis, Zakaria Halime, Adelais Trapali, Thomas Pino, Philipp Gotico, Christian Herrero, 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 des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Département Plateforme (PF I2BC), 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), and ANR-19-CE05-0020,LOCO,Processus Photoinduit d'Activation à 2 Electrons du CO2(2019)
Subjects: 010405 organic chemistry, Chemistry, Building and Construction, 010402 general chemistry, Photochemistry, 01 natural sciences, Porphyrin, 0104 chemical sciences, Catalysis, Reduction (complexity), chemistry.chemical_compound, Photocatalysis, [CHIM]Chemical Sciences, Electrical and Electronic Engineering, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2021
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21. Shaping the Electrocatalytic Performance of Metal Complexes for CO2 Reduction

Author: Zakaria Halime, Ally Aukauloo, Philipp Gotico, Winfried Leibl, 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 Moléculaire et des Matériaux d'Orsay (ICMMO), and Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Chemistry, Inorganic chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Electrocatalyst, 01 natural sciences, Catalysis, 0104 chemical sciences, Metal, Reduction (complexity), visual_art, Electrochemistry, visual_art.visual_art_medium, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Electrochemical reduction of carbon dioxide
Abstract: International audience; The mass scale catalytic transformation of carbon dioxide (CO2) into reduced forms of carbon is an imperative to address the ever-increasing anthropogenic emission. Understanding the mechanistic routes leading to the multi-electron-proton conversion of CO2 provides handles for chemists to overcome the kinetically and thermodynamically hard challenges and further optimize these processes. Through extensive electrochemical investigations, Prof. J-M. Savéant and coworkers have made accessible to chemists invaluable electro-analytical tools to address and position the electrocatalytic performance of molecular catalysts grounded on a theoretical basis. Furthermore, he has bequeathed lessons to future generations on ways to improve the catalytic activity and on the electrocatalytic zone we must target. As a tribute to his accomplishments, we recall here a few aspects on the tuning of iron porphyrin catalysts by playing on electronic effects, proton delivery, hydrogen bonding and electrostatic interactions and its implications to other catalytic systems.
Published: 2021
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22. Conjugated Polymer Nanostructures for Photocatalysis under Visible-Light

Author: Remita, H., Yuan, X., Jully Patel, J., Aukauloo, A., Winfried Leibl, W., Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Service de Bioénergétique, Biologie Stucturale, et Mécanismes (SB2SM), 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)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO)
Subjects: [CHIM]Chemical Sciences
Abstract: International audience
Published: 2021

23. Through-Space Electrostatic Interactions Surpass Classical Through-Bond Electronic Effects in Enhancing CO

Author: Asma, Khadhraoui, Philipp, Gotico, Winfried, Leibl, Zakaria, Halime, and Ally, Aukauloo
Abstract: In his pioneering work to unravel the catalytic power of enzymes, Warshel has pertinently validated that electrostatic interactions play a major role in the activation of substrates. Implementing such chemical artifice in molecular catalysts may help improve their catalytic properties. In this study, a series of tetra-, di-, and mono-substituted iron porphyrins with cationic imidazolium groups were designed. Their presence in the second coordination sphere helped stabilize the [Fe-CO
Published: 2020

24. Visible light-driven simultaneous water oxidation and quinone reduction by a nano-structured conjugated polymer without co-catalysts

Author: Ally Aukauloo, Stéphanie Mendes Marinho, Winfried Leibl, Jully Patel, Hynd Remita, Xiaojiao Yuan, 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), Photocatalyse et Biohydrogène (LPB), 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), 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), Service de Bioénergétique, Biologie Stucturale, et Mécanismes (SB2SM), 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)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Système membranaires, photobiologie, stress et détoxication (SMPSD), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010)
Subjects: nanosheets, Photosystem II, [SDV]Life Sciences [q-bio], Plastoquinone, 02 engineering and technology, 010402 general chemistry, Photochemistry, chemistry, 01 natural sciences, Redox, Artificial photosynthesis, oxygen evolution, chemistry.chemical_compound, [CHIM]Chemical Sciences, Chemistry, Oxygen evolution, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, Photoelectrochemical cell, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Quinone, hydrogen, Water splitting, nanoparticles, 0210 nano-technology, photocatalysis
Abstract: Place: Cambridge Publisher: Royal Soc Chemistry WOS:000550969100002; In artificial photosynthesis, chemists are aiming to borrow principles from natural photosynthesis to develop photoelectrochemical cells (PEC) for water splitting. The water plastoquinone photo-oxidoreductase enzyme, also known as photosystem II, uses light to perform the four-electron, four-proton oxidation of water to dioxygen and stores reducing equivalents in reduced forms of quinones which are ultimately used in dark reactions for the synthesis of energy-rich molecules. We report a nano-structured semiconducting conjugated polymer based on poly(diphenylbutadiyne) (nano-PDPB) and its photocatalytic activities towards the water oxidation reaction under visible light irradiation when dispersed in water in the absence of any sacrificial agents or co-catalysts. Charge recovery at the nano-PDPB directly or delayed in time was exemplified by the reduction of quinone acting as a hydrogen reservoir. In the absence of quinones as electron acceptors H(2)O(2)formation was detected, stemming from the partial reduction of O-2.
Published: 2020
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25. Efficient light activation of a [Ru(bpy)(tpy)Cl]+ catalyst by a porphyrin photosensitizer at small driving force

Author: Sofia Margiola, Annamaria Quaranta, Asterios Charisiadis, Athanassios G. Coutsolelos, Ally Aukauloo, Winfried Leibl, Georgios Charalambidis, 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), Photocatalyse et Biohydrogène (LPB), 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: inorganic chemicals, Water oxidation, [SDV]Life Sciences [q-bio], chemistry.chemical_element, 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, Ruthenium, Inorganic Chemistry, Light activation, Porphyrin, chemistry.chemical_compound, Electron transfer, 0502 economics and business, Materials Chemistry, 050207 economics, Physical and Theoretical Chemistry, chemistry.chemical_classification, 050208 finance, Quenching (fluorescence), 010405 organic chemistry, 05 social sciences, Chromophore, Electron acceptor, 0104 chemical sciences, Photophysics, chemistry, Intramolecular force
Abstract: Light activation of dyads containing porphyrins and a catalytic ruthenium complex having a high oxidation potential (~1 V vs SCE) is investigated by time-resolved spectroscopy. It is shown that activation of the ruthenium complex occurs through oxidative quenching of the chromophore in the presence of a reversible electron acceptor. Despite the lack of driving force for intramolecular electron transfer, an efficient intramolecular oxidation of the catalyst is observed, suggesting that porphyrins are attractive chromophores to activate oxidation catalysts throughout the visible spectrum.
Published: 2020
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26. Cover Feature: Spectroscopic Characterisation of a Bio‐Inspired Ni‐Based Proton Reduction Catalyst Bearing a Pentadentate N 2 S 3 Ligand with Improved Photocatalytic Activity

Author: Annamaria Quaranta, Régis Guillot, Ally Aukauloo, Zakaria Halime, Philipp Gotico, Cunming Liu, Dooshaye Moonshiram, Xiaoyi Zhang, Winfried Leibl, 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), Instituto Madrileno de Estudios Avanzados en Nanociencia (IMDEA), Argonne National Laboratory [Lemont] (ANL), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), and Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Reaction mechanism, X-ray absorption spectroscopy, Proton, 010405 organic chemistry, Ligand, Organic Chemistry, chemistry.chemical_element, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 01 natural sciences, Combinatorial chemistry, Catalysis, 0104 chemical sciences, Nickel, chemistry, Photocatalysis, [CHIM.COOR]Chemical Sciences/Coordination chemistry
Abstract: International audience; Inspired by the sulphur-rich environment found in active hydrogenase enzymes, a novel Ni-based proton reduction catalyst with pentadentate N2S3 ligand was synthesized. When coupled with a [Ru(bpy)3] 2+ photosensitiser and ascorbate as electron donor in a 1:1 mixture of dimethylacetamide and aqueous ascorbic acid/ascorbate buffer, the catalyst showed improved photocatalytic activity compared to a homologous counterpart with a tetradentate N2S2 ligand. The mechanistic pathway of photo-induced hydrogen evolution was comprehensively analysed through optical transient absorption (OTA) and time-resolved X-ray absorption spectroscopy (tr-XAS) revealing important electronic and structural changes in the catalytic system during photo-irradiation. It was found that the Ni (II) catalyst undergoes a photo-induced metal-centred reduction to form a Ni (I) intermediate bearing a distorted square bipyramidal geometry. Further kinetic analyses pointed out differences in charge separation dynamics between the pentadentate and tetradentate homologues.
Published: 2020
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27. Atropisomeric Hydrogen Bonding Control for CO 2 Binding and Enhancement of Electrocatalytic Reduction at Iron Porphyrins

Author: Régis Guillot, Winfried Leibl, Marie Sircoglou, Zakaria Halime, Ally Aukauloo, Loïc Roupnel, Philipp Gotico, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), and Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atropisomer, Coordination sphere, Urea, carbon dioxide reduction, hydrogen bonding, iron porphyrin, second coordination, biology, 010405 organic chemistry, Hydrogen bond, Chemistry, Inorganic chemistry, General Medicine, General Chemistry, Overpotential, 010402 general chemistry, Photochemistry, 01 natural sciences, Porphyrin, Catalysis, 0104 chemical sciences, Reduction (complexity), chemistry.chemical_compound, Kinetic isotope effect, Urea, biology.protein, [CHIM]Chemical Sciences, Electrochemical reduction of carbon dioxide, Carbon monoxide dehydrogenase
Abstract: International audience; The manipulation of the second coordination sphere for improving the electrocatalytic CO2 reduction has led to amazing breakthroughs with hydrogen bonding, local proton source, or electrostatic effects. We have developed two atropisomers of an iron porphyrin complex holding two urea functions acting as multiple hydrogen bonding tweezers to lock the metal bound CO2 in a similar fashion found in the carbon monoxide dehydrogenase (CODH) enzyme. We found that the  topological isomer with the two urea groups on the same side of the porphyrin platform provides a stronger binding affinity to tether the incoming CO2 substrate in comparison to the  disposition. However, the electrocatalytic activity of the  atropisomer outperforms its congener with one of the highest reported turnover frequency at low overpotential. The strong H/D KIE observed for the system indicates the existence of a tight water hydrogen bonding network for proton delivery which is disrupted upon addition of exogenous acid source. While the small H/D KIE for the  isomer and the enhanced electrocatalytic performance upon addition of stronger acid pertain the free access of protons to the bound CO2 on the opposite side of the urea arm.
Published: 2020
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28. Water Molecules Gating a Photoinduced One-Electron Two-Protons Transfer in a Tyrosine/Histidine (Tyr/His) Model of Photosystem II

Author: Pierre Fertey, Marie Sircoglou, Régis Guillot, Annamaria Quaranta, Maylis Orio, Athanassios G. Coutsolelos, Winfried Leibl, Adelais Trapali, Zakaria Halime, Ally Aukauloo, Georgios Chararalambidis, and Shyamal Das
Subjects: chemistry.chemical_classification, 010405 organic chemistry, General Medicine, General Chemistry, Electron acceptor, 010402 general chemistry, Photochemistry, 01 natural sciences, Porphyrin, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Radical ion, Intramolecular force, Flash photolysis, Imidazole, Proton-coupled electron transfer, Histidine
Abstract: We investigate a biomimetic model of a TyrZ /His190 pair, a hydrogen-bonded phenol/imidazole covalently attached to a porphyrin sensitizer. Laser flash photolysis in the presence of an external electron acceptor reveals the need for water molecules to unlock the light-induced oxidation of the phenol through an intramolecular pathway. Kinetics monitoring encompasses two fast phases with distinct spectral properties. The first phase is related to a one-electron transfer from the phenol to the porphyrin radical cation coupled with a domino two-proton transfer leading to the ejection of a proton from the imidazole-phenol pair. The second phase concerns conveying the released proton to the porphyrin N4 coordinating cavity. Our study provides an unprecedented example of a light-induced electron-transfer process in a TyrZ /His190 model of photosystem II, evidencing the movement of both the phenol and imidazole protons along an isoenergetic pathway.
Published: 2018
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29. Light-Induced Activation of the Du Bois [RhII2(Esp)2] Catalyst for Nitrogen Atom Transfer Reactions

Author: Régis Guillot, Philippe Dauban, Marie Sircoglou, Ally Aukauloo, Nhat Tam Vo, Clémence Ducloiset, Rajaa Farran, Zakaria Halime, Julien Buendia, and Winfried Leibl
Subjects: 010405 organic chemistry, Chemistry, Organic Chemistry, 010402 general chemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Analytical Chemistry, Artificial photosynthesis, Catalysis, Electron transfer, Nitrogen atom, Light induced, Organic chemistry, Photosensitizer, Physical and Theoretical Chemistry
Published: 2017
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30. Light-driven electron transfer in a modular assembly of a ruthenium(II) polypyridine sensitiser and a manganese(II) terpyridine unit separated by a redox active linkage. DFT analysis

Author: Stefano Protti, Ally Aukauloo, Rajaa Farran, Shyamal Das, Winfried Leibl, Reza Fallahpour, Annamaria Quaranta, Christian Herrero, Alison G. Tebo, and Marie-France Charlot
Subjects: 010405 organic chemistry, General Chemical Engineering, chemistry.chemical_element, General Chemistry, Chromophore, 010402 general chemistry, Photochemistry, 01 natural sciences, Redox, 0104 chemical sciences, law.invention, Ruthenium, Artificial photosynthesis, Bipyridine, chemistry.chemical_compound, Electron transfer, chemistry, law, Terpyridine, Electron paramagnetic resonance
Abstract: A series of ruthenium polypyridine-based complexes covalently bound to a terpyridine coordinating site for MnII ion coordination has been developed. A redox active unit separates the photoactive unit and the manganese complex. Introducing ester groups on the bipyridine skeleton allows modulation of redox properties of the chromophore. Intramolecular electron transfer from the MnII to the photogenerated RuIII was studied by time-resolved transient absorption and EPR. Photophysical studies support the participation of the imidazole unit in the electron transfer process from the Mn(II) complex and Ru(III) in the case of ester containing chromophores. DFT calculations were performed and used to rationalize the photophysical behavior of the complexes, in particular the effect of coordination of the MnII ion to the terpyridine cavity as well as the influence of the electron withdrawing groups on the Ru chromophore.
Published: 2017
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31. Spectroscopic Characterisation of a Bio-Inspired Ni-Based Proton Reduction Catalyst Bearing a Pentadentate N

Author: Philipp, Gotico, Dooshaye, Moonshiram, Cunming, Liu, Xiaoyi, Zhang, Régis, Guillot, Annamaria, Quaranta, Zakaria, Halime, Winfried, Leibl, and Ally, Aukauloo
Subjects: Rhenium, X-Ray Absorption Spectroscopy, Hydrogenase, Coordination Complexes, Protons, Ligands, Catalysis, Sulfur
Abstract: Inspired by the sulfur-rich environment found in active hydrogenase enzymes, a Ni-based proton reduction catalyst with pentadentate N
Published: 2019

32. A Reversible Electron Relay to Exclude Sacrificial Electron Donors in the Photocatalytic Oxygen Atom Transfer Reaction with O

Author: Nhat Tam, Vo, Yasmina, Mekmouche, Thierry, Tron, Régis, Guillot, Frédéric, Banse, Zakaria, Halime, Marie, Sircoglou, Winfried, Leibl, and Ally, Aukauloo
Abstract: Using light energy and O
Published: 2019

33. Frontispiz: Second‐Sphere Biomimetic Multipoint Hydrogen‐Bonding Patterns to Boost CO 2 Reduction of Iron Porphyrins

Author: Philipp Gotico, Bernard Boitrel, Régis Guillot, Marie Sircoglou, Annamaria Quaranta, Zakaria Halime, Winfried Leibl, and Ally Aukauloo
Subjects: General Medicine
Published: 2019
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34. Second-Sphere Biomimetic Multipoint Hydrogen-Bonding Patterns to Boost CO2 Reduction of Iron Porphyrins

Author: Philipp Gotico, Bernard Boitrel, Régis Guillot, Marie Sircoglou, Annamaria Quaranta, Zakaria Halime, Winfried Leibl, Ally Aukauloo, 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 des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Coordination sphere, urea, Overpotential, 010402 general chemistry, Photochemistry, porphyrins, 01 natural sciences, Catalysis, chemistry.chemical_compound, iron, Molecule, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Electrochemical reduction of carbon dioxide, carbon dioxide reduction, biology, 010405 organic chemistry, Hydrogen bond, General Medicine, General Chemistry, hydrogen bonding, Porphyrin, 3. Good health, 0104 chemical sciences, chemistry, 13. Climate action, biology.protein, Carbon monoxide dehydrogenase
Abstract: International audience; Inspired by nature's orchestra of chemical subtleties to activate and reduce CO2, we have developed a family of iron porphyrin derivatives in to which we have introduced urea groups functioning as multipoint hydrogen‐bonding pillars on the periphery of the porphyrinic ring. This structure closely resembles the hydrogen‐bond stabilization scheme of the carbon dioxide (CO2) adduct in the carbon monoxide dehydrogenase (CODH). We found that such changes to the second coordination sphere significantly lowered the overpotential for CO2 reduction in this family of molecular catalysts and importantly increased the CO2 binding rate while maintaining high turnover frequency (TOF) and selectivity. Entrapped water molecules within the molecular clefts were found to be the source of protons for the CO2 reduction.
Published: 2019
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35. A Reversible Electron Relay to Exclude Sacrificial Electron Donors in the Photocatalytic Oxygen Atom Transfer Reaction with O2 in Water

Author: Régis Guillot, Ally Aukauloo, Thierry Tron, Nhat Tam Vo, Winfried Leibl, Marie Sircoglou, Zakaria Halime, Yasmina Mekmouche, Frédéric Banse, 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)
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Alkene, [SDV]Life Sciences [q-bio], Reactive intermediate, Substrate (chemistry), General Medicine, General Chemistry, Electron acceptor, 010402 general chemistry, Photochemistry, 01 natural sciences, Aldehyde, Catalysis, time-resolved spectroscopy, 0104 chemical sciences, iron complexes, Radical ion, chemistry, Oxidizing agent, Photosensitizer, oxygen atom transfer, photocatalysis, electron relay
Abstract: International audience; Using light energy and O2 for the direct chemical oxidation of organic substrates is a major challenge. A limitation is the use of sacrificial electron donors to activate O2 by reductive quenching of the photosensitizer, generating undesirable side products. A reversible electron acceptor, methyl viologen, can act as electron shuttle to oxidatively quench the photosensitizer, [Ru(bpy)3 ]2+ , generating the highly oxidized chromophore and the powerful reductant methyl-viologen radical MV+. . MV+. can then reduce an iron(III) catalyst to the iron(II) form and concomitantly O2 to O2.- in an aqueous medium to generate an active iron(III)-(hydro)peroxo species. The oxidized photosensitizer is reset to its ground state by oxidizing an alkene substrate to an alkenyl radical cation. Closing the loop, the reaction of the iron reactive intermediate with the substrate or its radical cation leads to the formation of two oxygenated compounds, the diol and the aldehyde following two different pathways.
Published: 2019
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36. Spectroscopic Characterization of Bio-inspired Ni-based Proton Reduction Catalyst Bearing Pentadentate N2S3 Ligand with Improved Photocatalytic Activity

Author: Winfried Leibl, Annamaria Quaranta, Dooshaye Moonshiram, Ally Aukauloo, Cunming Liu, Xiaoyi Zhang, Régis Guillot, Zakaria Halime, Philipp Gotico, 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), Laboratoire Bioénergétique Membranaire et Stress (LBMS), 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), 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), and Photocatalyse et Biohydrogène (LPB)
Subjects: X-ray absorption spectroscopy, Absorption spectroscopy, 010405 organic chemistry, Chemistry, Ligand, [SDV]Life Sciences [q-bio], Organic Chemistry, Electron donor, General Chemistry, 010402 general chemistry, Photochemistry, Ascorbic acid, 01 natural sciences, Catalysis, 0104 chemical sciences, Bipyridine, chemistry.chemical_compound, Photocatalysis, Optical Transient Absorption, Time-Resolved X-ray Absorption Spectroscopy, Bio-inspired Catalysts, Hydrogen
Abstract: International audience; Inspired by the sulphur-rich environment found in active hydrogenase enzymes, a novel Ni-based proton reduction catalyst with pentadentate N 2 S 3 ligand was synthesized. When coupled with a [Ru(bpy) 3 ] 2+ photosensitiser and ascorbate as electron donor in a 1:1 mixture of dimethylacetamide and aqueous ascorbic acid/ascorbate buffer, the catalyst showed improved photocatalytic activity compared to a homologous counterpart with a tetradentate N 2 S 2 ligand. The mechanistic pathway of photo-induced hydrogen evolution was comprehensively analysed through optical transient absorption (OTA) and time-resolved X-ray absorption spectroscopy (tr-XAS) revealing important electronic and structural changes in the catalytic system during photo-irradiation. It was found that the Ni (II) catalyst undergoes a photo-induced metal-centred reduction to form a Ni (I) intermediate bearing a distorted square bipyramidal geometry. Further kinetic analyses pointed out differences in charge separation dynamics between the pentadentate and tetradentate homologues.
Published: 2019
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37. Second-Sphere Biomimetic Multipoint Hydrogen-Bonding Patterns to Boost CO

Author: Philipp, Gotico, Bernard, Boitrel, Régis, Guillot, Marie, Sircoglou, Annamaria, Quaranta, Zakaria, Halime, Winfried, Leibl, and Ally, Aukauloo
Subjects: Models, Molecular, Molecular Structure, Biomimetic Materials, Metalloporphyrins, Iron, Hydrogen Bonding, Carbon Dioxide, Crystallography, X-Ray
Abstract: Inspired by nature's orchestra of chemical subtleties to activate and reduce CO
Published: 2018

38. Innenrücktitelbild: Phthalocyanine as a Bioinspired Model for Chlorophyll f ‐Containing Photosystem II Drives Photosynthesis into the Far‐Red Region (Angew. Chem. 22/2021)

Author: Ally Aukauloo, Rajaa Farran, Jorge Follana-Berná, Winfried Leibl, Annamaria Quaranta, and Ángela Sastre-Santos
Subjects: chemistry.chemical_compound, Photosystem II, Chemistry, Chlorophyll f, Phthalocyanine, Far-red, General Medicine, Photochemistry, Photosynthesis
Published: 2021
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39. Inside Back Cover: Phthalocyanine as a Bioinspired Model for Chlorophyll f ‐Containing Photosystem II Drives Photosynthesis into the Far‐Red Region (Angew. Chem. Int. Ed. 22/2021)

Author: Rajaa Farran, Annamaria Quaranta, Jorge Follana-Berná, Ally Aukauloo, Winfried Leibl, and Ángela Sastre-Santos
Subjects: chemistry.chemical_compound, chemistry, Photosystem II, Chlorophyll f, INT, Phthalocyanine, Far-red, Cover (algebra), General Chemistry, Photosynthesis, Photochemistry, Catalysis
Published: 2021
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40. Cover Feature: Through‐Space Electrostatic Interactions Surpass Classical Through‐Bond Electronic Effects in Enhancing CO 2 Reduction Performance of Iron Porphyrins (ChemSusChem 5/2021)

Author: Asma Khadhraoui, Zakaria Halime, Winfried Leibl, Philipp Gotico, and Ally Aukauloo
Subjects: Reduction (complexity), General Energy, Materials science, Cover (topology), Feature (computer vision), Chemical physics, General Chemical Engineering, Electronic effect, Environmental Chemistry, General Materials Science, Electrostatics, Space (mathematics)
Published: 2021
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41. Local ionic liquid environment at a modified iron porphyrin catalyst enhances the electrocatalytic performance of CO

Author: Asma, Khadhraoui, Philipp, Gotico, Bernard, Boitrel, Winfried, Leibl, Zakaria, Halime, and Ally, Aukauloo
Abstract: In this study we report a strategy to attach methylimidazolium fragments as ionic liquid units on an established iron porphyrin catalyst for the selective reduction of CO2 to CO. Importantly, we found that the tetra-methylimidazolium containing porphyrin exhibits an exalted electrocatalytic activity at low overpotential in water precluding the need for an external proton donor.
Published: 2018

42. Visible-Light-Driven Reduction of CO$_2$ to CO and Its Subsequent Valorization in Carbonylation Chemistry and $^{13}$C Isotope Labeling

Author: Antonio Del Vecchio, Ally Aukauloo, Annamaria Quaranta, Winfried Leibl, Philipp Gotico, Davide Audisio, Zakaria Halime, 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), Service de Chimie Bio-Organique et de Marquage (SCBM), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-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 National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-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 National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), IRAMAT - Laboratoire Métallurgies et Cultures (IRAMAT - LMC), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), Laboratoire de Marquage au Carbone 14 (LMC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Médicaments et Technologies pour la Santé (MTS), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), ANR-11-LABX-0039,CHARMMMAT,CHimie des ARchitectures MoléculairesMultifonctionnelles et des MATériaux(2011), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), European Project: 675071,H2020,H2020-MSCA-ITN-2015,ISOTOPICS(2016), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Mécanismes fondamentaux de la Bioénergétique (LMB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Photocatalyse et Biohydrogène (LPB), 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), 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), 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 National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Médicaments et Technologies pour la Santé (MTS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay, and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)
Subjects: photoredox catalysis, [SDV]Life Sciences [q-bio], homogeneous catalysts, chemistry.chemical_element, carbonylation, 010402 general chemistry, Photochemistry, carbon-dioxide, 01 natural sciences, Analytical Chemistry, Artificial photosynthesis, Catalysis, Isotopic labeling, chemistry.chemical_compound, Physical and Theoretical Chemistry, isotopic labeling, 010405 organic chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, continuous-flow, Organic Chemistry, Photoredox catalysis, photocatalytic reduction, carbon dioxide, [CHIM.CATA]Chemical Sciences/Catalysis, photochemical reduction, 0104 chemical sciences, Ruthenium, formic-acid, LPB, chemistry, highly efficient, 13. Climate action, artificial photosynthesis, Photocatalysis, rhenium(i) complex, Carbonylation, B3S, photocatalysis, Carbon monoxide, metal-complexes
Abstract: WOS:000441548500003; International audience; A convenient and safe approach in valorizing carbon monoxide (CO) produced from the photocatalytic reduction of carbon dioxide (CO2) has been investigated. Visible light was used to drive an optimized photocatalytic reduction using a ruthenium trisbipyridine complex as a sensitizer and a rhenium bipyridyl carbonyl complex as a catalyst to perform an efficient reduction of CO2 to CO, which was then simultaneously utilized in a palladium-catalyzed aminocarbonylation reaction at room temperature. This approach provides safe handling of the produced CO which also opens the way for a more efficient application of C-13-isotope and C-14-radioisotope-labeled CO2 in pharmaceutically relevant drug labeling.
Published: 2018
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43. Photoinduced electron transfer in a molecular dyad by nanosecond pump-pump-probe spectroscopy

Author: Christophe Lefumeux, Ally Aukauloo, Van-Thai Pham, Winfried Leibl, V. Maslova, Minh-Huong Ha-Thi, Annamaria Quaranta, Thomas Pino, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Photophysique Moléculaire, Université Paris-Sud - Paris 11 (UP11), Système membranaires, photobiologie, stress et détoxication (SMPSD), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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), Photocatalyse et Biohydrogène (LPB), 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), 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), Centre de Photonique Biomédicale (CPBM), Centre Laser Université Paris Sud, Service de Bioénergétique, Biologie Stucturale, et Mécanismes (SB2SM), Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre Laser de l'Université Paris Sud (CLUPS), Université Paris-Sud - Paris 11 (UP11)-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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, photosensitizer, [SDV]Life Sciences [q-bio], reduction, 010402 general chemistry, Photochemistry, 7. Clean energy, 01 natural sciences, Redox, Photoinduced electron transfer, photocatalysts, Electron transfer, catalytic water oxidation, solar-energy, Molecule, Physical and Theoretical Chemistry, chemistry.chemical_classification, 010405 organic chemistry, accumulative charge separation, Electron acceptor, Chromophore, Nanosecond, 0104 chemical sciences, LPB, Photoinduced charge separation, chemistry, artificial photosynthesis, photosystem-ii, co2, B3S, complex
Abstract: International audience; The design of robust and inexpensive molecular photocatalysts for the conversion of abundant stable molecules like H2O and CO2 into an energetic carrier is one of the major fundamental questions for scientists nowadays. The outstanding challenge is to couple single photoinduced charge separation events with the sequential accumulation of redox equivalents at the catalytic unit for performing multielectronic catalytic reactions. Herein, double excitation by nanosecond pump-pump-probe experiments was used to interrogate the photoinduced charge transfer and charge accumulation on a molecular dyad composed of a porphyrin chromophore and a ruthenium-based catalyst in the presence of a reversible electron acceptor. An accumulative charge transfer state is unattainable because of rapid reverse electron transfer to the photosensitizer upon the second excitation and the low driving force of the forward photodriven electron transfer reaction. Such a method allows the fundamental understanding of the relaxation mechanism after two sequential photon absorptions, deciphering the undesired electron transfer reactions that limit the charge accumulation efficiency. This study is a step toward the improvement of synthetic strategies of molecular photocatalysts for light-induced charge accumulation and more generally, for solar energy conversion.
Published: 2018
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44. Local ionic liquid environment at a modified iron porphyrin catalyst enhances the electrocatalytic performance of CO2 to CO reduction in water

Author: Bernard Boitrel, Zakaria Halime, Winfried Leibl, Asma Khadhraoui, Ally Aukauloo, Philipp Gotico, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Mécanismes fondamentaux de la Bioénergétique (LMB), 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 des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)
Subjects: Proton, 010405 organic chemistry, Inorganic chemistry, Metals and Alloys, General Chemistry, Overpotential, 010402 general chemistry, 01 natural sciences, Porphyrin, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Reduction (complexity), chemistry.chemical_compound, chemistry, Ionic liquid, Materials Chemistry, Ceramics and Composites, polycyclic compounds, [CHIM]Chemical Sciences, Selective reduction, heterocyclic compounds
Abstract: International audience; In this study we report a strategy to attach methylimidazolium fragments as ionic liquid units on an established iron porphyrin catalyst for the selective reduction of CO2 to CO. Importantly, we found that the tetra-methylimidazolium containing porphyrin exhibits an exalted electrocatalytic activity at low overpotential in water precluding the need for an external proton donor.
Published: 2018
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45. Snapshots of Light Induced Accumulation of Two Charges on Methylviologen using a Sequential Nanosecond Pump–Pump Photoexcitation

Author: Christophe Lefumeux, Minh-Huong Ha-Thi, Ally Aukauloo, Annamaria Quaranta, Thu-Trang Tran, Winfried Leibl, Thomas Pino, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-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), Photocatalyse et Biohydrogène (LPB), 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), 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), Centre de Photonique Biomédicale (CPBM), Centre Laser Université Paris Sud, Laboratoire des Mécanismes fondamentaux de la Bioénergétique (LMB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre Laser de l'Université Paris Sud (CLUPS), Université Paris-Sud - Paris 11 (UP11)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, 010405 organic chemistry, [SDV]Life Sciences [q-bio], Electron donor, Electron, Electron acceptor, Nanosecond, 010402 general chemistry, Electrochemistry, Photochemistry, 01 natural sciences, 0104 chemical sciences, Photoexcitation, chemistry.chemical_compound, chemistry, General Materials Science, Photosensitizer, Physical and Theoretical Chemistry, Ground state, ComputingMilieux_MISCELLANEOUS
Abstract: Methylviologen (MV2+) is perhaps the most used component as a reversible electron acceptor in photophysical studies. While MV2+ is most commonly implicated as a reversible one-electron mediator, its electrochemical properties clearly evidence two successive one-electron reduction processes. In this report, we have investigated on the light driven two-charge accumulation on MV2+ using a multicomponent system composed of the prototypical molecular photosensitizer [Ru(bpy)3]2+ and MV2+ in the presence of ascorbate as reversible electron donor. The sequential addition of two electrons on the methylviologen was tracked upon sequential excitation of the [Ru(bpy)3]2+ at optimized concentration of the electron acceptor. The charge accumulated state carries an energy of 0.9 eV above the ground state and has a lifetime of ca. 50 μs. We have reached a fairly good global yield of approximately 9% for the two-charge accumulation. This result clearly demonstrates the potential of this simple approach for applications i...
Published: 2018
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46. Intramolecular photoinduced electron transfer in cobalt(II) chlathrochelate-zinc porphyrin assemblies leading to long-lived <font>Co(I)</font> species

Author: Sanae El Ghachtouli, Régis Guillot, Ally Aukauloo, and Winfried Leibl
Subjects: Zinc porphyrin, Electron transfer, chemistry.chemical_compound, chemistry, Intramolecular force, chemistry.chemical_element, Electron donor, General Chemistry, Electrochemistry, Photochemistry, Porphyrin, Cobalt, Photoinduced electron transfer
Abstract: We report herein the synthesis and characterization of novel cobalt chlathrochelate-zinc porphyrin assemblies. X-ray data and electrochemical studies support the formation and maintenance of these structures both in solid and solution states. Light induced charge accumulation at the cobalt center was realized in the presence of a sacrificial electron donor. The photogenerated Co(I) species was stable in the ms time scale in aqueous medium.
Published: 2014
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47. Time-resolved infrared spectroscopy in the study of photosynthetic systems

Author: Alberto Mezzetti, Winfried Leibl, Photocatalyse et Biohydrogène (LPB), 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), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-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), Photocatalyse et Biohydrogène ( LPB ), Département Biochimie, Biophysique et Biologie Structurale ( B3S ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 ), Laboratoire de Réactivité de Surface ( LRS ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), and Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Sud - Paris 11 ( UP11 )
Subjects: Chlorophyll, Vibrational spectroscopy, Photosystem I, Light-harvesting systems, Photosystem II, Infrared, Ubiquinone, [SDV]Life Sciences [q-bio], Photosynthetic Reaction Center Complex Proteins, Analytical chemistry, Infrared spectroscopy, Rhodobacter sphaeroides, Plant Science, 010402 general chemistry, Photochemistry, Bacterial reaction centers, Thylakoids, 01 natural sciences, Biochemistry, Proton transfer, law.invention, Electron transfer, symbols.namesake, law, Spectroscopy, Fourier Transform Infrared, Photosynthesis, Spectroscopy, Reaction centers, Laser diode, [ SDV ] Life Sciences [q-bio], Chemistry, Chlorophyll A, 010401 analytical chemistry, Cell Biology, General Medicine, Nanosecond, FTIR difference spectroscopy, Step-scan FTIR, Carotenoids, 0104 chemical sciences, Kinetics, Fourier transform, symbols, Rapid-scan FTIR
Abstract: International audience; Time-resolved (TR) infrared (IR) spectroscopy in the nanosecond to second timescale has been extensively used, in the last 30 years, in the study of photosynthetic systems. Interesting results have also been obtained at lower time resolution (minutes or even hours). In this review, we first describe the used techniques-dispersive IR, laser diode IR, rapid-scan Fourier transform (FT)IR, step-scan FTIR-underlying the advantages and disadvantages of each of them. Then, the main TR-IR results obtained so far in the investigation of photosynthetic reactions (in reaction centers, in light-harvesting systems, but also in entire membranes or even in living organisms) are presented. Finally, after the general conclusions, the perspectives in the field of TR-IR applied to photosynthesis are described.
Published: 2017
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48. Time-Resolved Interception of Multiple-Charge Accumulation in a Sensitizer-Acceptor Dyad

Author: Thomas Pino, Van-Thai Pham, Annamaria Quaranta, Ally Aukauloo, Christophe Lefumeux, Minh-Huong Ha-Thi, Thierry Chamaillé, Winfried Leibl, Stéphanie Mendes Marinho, 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), Photocatalyse et Biohydrogène (LPB), 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: energy conversion, photosynthesis, 010405 organic chemistry, Chemistry, [SDV]Life Sciences [q-bio], Electron donor, General Medicine, General Chemistry, Nanosecond, Chromophore, 010402 general chemistry, Photochemistry, electron transfer, 01 natural sciences, Acceptor, Redox, Catalysis, time-resolved spectroscopy, 0104 chemical sciences, Electron transfer, chemistry.chemical_compound, Bipyridine, molecular dyads, Time-resolved spectroscopy
Abstract: Biomimetic models that contain elements of photosynthesis are fundamental in the development of synthetic systems that can use sunlight to produce fuel. The critical task consists of running several rounds of light-induced charge separation, which is required to accumulate enough redox equivalents at the catalytic sites for the target chemistry to occur. Long-lived first charge-separated state and distinct electronic signatures for the sequential charge accumulated species are essential features to be able to track these events on a spectroscopic ground. Herein, we use a double-excitation nanosecond pump-pump-probe experiment to interrogate two successive rounds of photo-induced electron transfer on a molecular dyad containing a naphthalene diimide (NDI) linked to a [Ru(bpy)3 ](2+) (bpy=bipyridine) chromophore by using a reversible electron donor. We report an unprecedented long-lived two-electron charge accumulation (t=200 μs).
Published: 2017
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49. Light-induced tryptophan radical generation in a click modular assembly of a sensitiser-tryptophan residue

Author: Christian Herrero, Sujitraj Sheth, Boris Vauzeilles, Aurélie Baron, Winfried Leibl, Ally Aukauloo, Institut de Chimie des Substances Naturelles (ICSN), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Free Radicals, Light, Protonation, 010402 general chemistry, Photochemistry, 01 natural sciences, Redox, Ruthenium, law.invention, Electron Transport, Electron transfer, Deprotonation, law, Physical and Theoretical Chemistry, Electron paramagnetic resonance, [CHIM.ORGA]Chemical Sciences/Organic chemistry, 010405 organic chemistry, Chemistry, Electron Spin Resonance Spectroscopy, Tryptophan, Chromophore, 0104 chemical sciences, Click chemistry, Click Chemistry, Protons, Oxidation-Reduction
Abstract: International audience; Click chemistry was used as an efficient method to covalently attach a chromophore to an amino acid. Such easily prepared model systems allow for time-resolved studies of one-electron oxidation reactions by the excitation of the chromophore by a laser flash. The model complex ruthenium-tryptophan (Ru-Trp) has been synthesised and studied for its photophysical and electrochemical properties. Despite a small driving force of less than 100 meV, excitation with a laser flash results in fast internal electron transfer leading to the formation of the protonated radical (Trp˙H(+)). At neutral pH electron transfer is followed by deprotonation to form the neutral Trp˙ radical with the rate depending on the concentration of water acting as the proton acceptor. The formation of the tryptophan radical was confirmed by EPR.
Published: 2013
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50. Identification of the Different Mechanisms of Activation of a [RuII(tpy)(bpy)(OH2)]2+ Catalyst by Modified Ruthenium Sensitizers in Supramolecular Complexes

Author: Reza-Ali Fallahpour, Annamaria Quaranta, Ally Aukauloo, Christian Herrero, and Winfried Leibl
Subjects: Supramolecular chemistry, chemistry.chemical_element, Chromophore, Photochemistry, Acceptor, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Catalysis, Ruthenium, Electron transfer, Bipyridine, chemistry.chemical_compound, General Energy, Catalytic oxidation, chemistry, Physical and Theoretical Chemistry
Abstract: We report the synthesis and photophysical studies of two different complexes incorporating a chromophore and a catalyst within the same structure. The chromophores used are of the form [(bpy)2(phen)RuII]2+ and [(COOEt)2bpy)2(phen)RuII]2+. The electron-withdrawing auxophores in the periphery of the bipyridine ligands convey the chromophores with different chemical and photophysical properties. The catalyst incorporated is [RuII(tpy)(bpy)(OH2)]2+ which has been shown to carry out the catalytic oxidation of water and organic substrates. We present the different mechanisms of light-driven activation observed for the catalyst. Depending on the electronic properties of the chromophores, these can act as antenna systems by activating the catalyst via energy transfer followed by electron transfer to an acceptor or as chromophores, in which case activation of the catalyst is done by direct electron transfer from the photo-oxidized sensitizer. The oxidized form of the catalyst formed by either mechanism is stable o...
Published: 2013
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