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151. Nickel(0)-Induced β-H Elimination of Magnesium Alkyls: Formation and Reactivity of Heterometallic Hydrides

Author: Xin Xu, Jiasu Huang, Iker del Rosal, Xizhou Zheng, Laurent Maron, Bei Zhao, Soochow University, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Inorganic Chemistry, Nickel, chemistry, Magnesium, Polymer chemistry, chemistry.chemical_element, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract: We report the synthesis and reactivity of heterometallic Mg-Ni complexes with bridging hydrides. Treatment of magnesium monoalkyl complexes, which are supported by a tridentate β-diketiminato ligand bearing a pendent phosphine group, with nickel(0) reagent Ni(COD)
Published: 2020
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152. Dinitrogen Cleavage by a Heterometallic Cluster Featuring Multiple Uranium-Rhodium Bonds

Author: Laurent Maron, Xiaoqing Xin, Yue Zhao, Shuao Wang, Congqing Zhu, Iskander Douair, Nanjing University (NJU), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chemistry, chemistry.chemical_element, General Chemistry, Nitride, Uranium, 010402 general chemistry, Triple bond, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Rhodium, Metal, Colloid and Surface Chemistry, Transition metal, visual_art, Polymer chemistry, visual_art.visual_art_medium, Cluster (physics), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: Reduction of dinitrogen (N2) is a major challenge for chemists. Cooperation of multiple metal centers to break the strong N2 triple bond has been identified as a crucial step in both the industrial and the natural ammonia syntheses. However, reports of the cleavage of N2 by a multimetallic uranium complex remain extremely rare, although uranium species were used as catalyst in the early Harber-Bosch process. Here we report the cleavage of N2 to two nitrides by a multimetallic uranium-rhodium cluster at ambient temperature and pressure. The nitride product further reacts with acid to give substantial yields of ammonium. The presence of uranium-rhodium bond in this multimetallic cluster was revealed by X-ray crystallographic and computational studies. This study demonstrates that the multimetallic clusters containing uranium and transition metals are promising materials for N2 fixation and reduction.
Published: 2020
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153. Reductive Hexamerization of CO Involving Cooperativity Between Magnesium(I) Reductants and [Mo(CO)6]: Synthesis of Well-Defined Magnesium Benzenehexolate Complexes

Author: K. Yuvaraj, Albert Paparo, Iskander Douair, Aidan J. R. Matthews, Cameron Jones, Laurent Maron, School of Chemistry, Monash University [Clayton], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Magnesium, Potassium, NacNac, chemistry.chemical_element, Cooperativity, General Chemistry, General Medicine, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Homogeneous, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Well-defined, Carbon monoxide
Abstract: Reactions of two magnesium(I) compounds, [{(Ar Nacnac)Mg}2 ] (Ar Nacnac=[HC(MeCNAr)2 ]- ; Ar=mesityl (Mes) or o-xylyl (Xyl)), with CO in the presence of [Mo(CO)6 ] lead to the reductive hexamerization of CO, and formation of magnesium benzenehexolate complexes, [{(Ar Nacnac)Mg}6 (C6 O6 )]. [Mo(CO)6 ] is not consumed in these reactions, but is apparently required to initiate (or catalyze) the CO hexamerizations. A range of studies were used to probe the mechanism of formation of the benzenehexolate complexes. The magnesium(I) reductive hexamerizations of CO are closely related to Liebig's reduction of CO with molten potassium (to give K6 C6 O6 , amongst other products), originally reported in 1834. As the mechanism of that reaction is still unknown, it seems reasonable that magnesium(I) reductions of CO could prove useful homogeneous models for its elucidation, and for the study of other C-C bond forming reactions that use CO as a C1 feedstock (e.g. the Fischer-Tropsch process).
Published: 2020
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154. NH3 formation from N2 and H2 mediated by molecular tri-iron complexes

Author: Matthias Freytag, Sébastien Bontemps, Marc-Kevin Zaretzke, Dirk Baabe, Iker del Rosal, Katharina Münster, Laurent Maron, Marc D. Walter, Yannick Coppel, Peter G. Jones, Matthias Reiners, Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Deutsche Forschungsgemeinschaft (DFG) - Emmy Noether (WA 2513/2) and Heisenberg (WA 2513/6-8) programs, Humboldt Foundation, Chinese Academy of Science, CNRS, Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010405 organic chemistry, Chemistry, General Chemical Engineering, Solid-state, Nitrogenase, Protonation, General Chemistry, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Catalysis, Electron transfer, Ammonia, chemistry.chemical_compound, Polymer chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Bar (unit)
Abstract: International audience; Living systems carry out the reduction of N2 to ammonia (NH3) through a series of protonation and electron transfer steps under ambient conditions using the enzyme nitrogenase. In the chemical industry, the Haber-Bosch process hydrogenates N2 but requires high temperatures and pressures. Both processes rely on iron-based catalysts, but molecular iron complexes that promote the formation of NH3 on addition of H2 to N2 have remained difficult to devise. Here, we isolate the tri(iron)bis(nitrido) complex [(Cp'Fe)3(μ3-N)2] (in which Cp' = η5-1,2,4-(Me3C)3C5H2), which is prepared by reduction of [Cp'Fe(μ-I)]2 under an N2 atmosphere and comprises three iron centres bridged by two μ3-nitrido ligands. In solution, this complex reacts with H2 at ambient temperature (22 °C) and low pressure (1 or 4 bar) to form NH3. In the solid state, it is converted into the tri(iron)bis(imido) species, [(Cp'Fe)3(μ3-NH)2], by addition of H2 (10 bar) through an unusual solid-gas, single-crystal-to-single-crystal transformation. In solution, [(Cp'Fe)3(μ3-NH)2] further reacts with H2 or H+ to form NH3.
Published: 2020
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155. Rationalizing the Reactivity of Mixed Allyl Rare-Earth Borohydride Complexes with DFT Studies

Author: Laurent Maron, Jashvini Jothieswaran, Sami Fadlallah, Iker del Rosal, Marc Visseaux, Fanny Bonnet, Université de Lille, CNRS, INRA, ENSCL, Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS], Laboratoire de physique et chimie des nano-objets [LPCNO], Unité Matériaux et Transformations - UMR 8207 [UMET], 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), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Region Occitanie2016-p0833, Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL)
Subjects: rare earth, ring-opening polymerization, Rare earth, lcsh:Chemical technology, 010402 general chemistry, Borohydride, 01 natural sciences, Ring-opening polymerization, DFT, Catalysis, lcsh:Chemistry, chemistry.chemical_compound, Polymer chemistry, borohydride, lcsh:TP1-1185, Reactivity (chemistry), Physical and Theoretical Chemistry, chemistry.chemical_classification, cyclic esters, 010405 organic chemistry, Ligand, Chemistry, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 0104 chemical sciences, 3. Good health, [CHIM.POLY]Chemical Sciences/Polymers, lcsh:QD1-999, Polymerization, Density functional theory, allyl
Abstract: The reactivity of rare-earth complexes RE(BH4)2(C3H5)(THF)x (RE = La, Nd, Sm, Y, Sc) toward the Ring-Opening Polymerization (ROP) of &epsilon, caprolactone (&epsilon, CL) was rationalized by Density Functional Theory (DFT) calculations. Even if the polymerization reaction can be initiated by both RE-(BH4) and RE-allyl bonds, experimental investigations have shown that the initiation via the borohydride ligand was favored, as no allyl group could be detected at the chain-end of the resulting polymers. DFT studies could confirm these observations, as it was highlighted that even if the activation barriers are both accessible, the allyl group is not active for the ROP of &epsilon, CL due to the formation of a highly stable intermediate that disfavors the subsequent ring-opening.
Published: 2020
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156. Reductive Hexamerization of CO Involving Cooperativity Between Magnesium(I) Reductants and [Mo(CO)

Author: Albert, Paparo, K, Yuvaraj, Aidan J R, Matthews, Iskander, Douair, Laurent, Maron, and Cameron, Jones
Abstract: Reactions of two magnesium(I) compounds, [{(
Published: 2020

157. Metallacyclic actinide catalysts for dinitrogen conversion to ammonia and secondary amines

Author: Rory P. Kelly, Tatsumi Ochiai, Megan L. Seymour, Laurent Maron, Polly L. Arnold, Francis Y. T. Lam, EPCC [Edinburgh], University of Edinburgh, Université de Tsukuba = University of Tsukuba, Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), EaStCHEM School of Chemistry, University of St Andrews [Scotland], Nanomagnétisme (LPCNO), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Silanes, 010405 organic chemistry, General Chemical Engineering, Organic Chemistry, General Chemistry, Actinide, 010402 general chemistry, Ligands, 01 natural sciences, 0104 chemical sciences, Catalysis, Metal, Ammonia, chemistry.chemical_compound, Temperature and pressure, chemistry, visual_art, Polymer chemistry, Chemical Sciences, visual_art.visual_art_medium, Surface modification, Molecule, MESH: chemi, [CHIM]Chemical Sciences, Chemical bonding
Abstract: International audience; Chemists have spent over a hundred years trying to make ambient temperature/pressure catalytic systems that can convert atmospheric dinitrogen into ammonia or directly into amines. A handful of successful d-block metal catalysts have been developed in recent years, but even binding of dinitrogen to an f-block metal cation is extremely rare. Here we report f-block complexes that can catalyse the reduction and functionalization of molecular dinitrogen, including the catalytic conversion of molecular dinitrogen to a secondary silylamine. Simple bridging ligands assemble two actinide metal cations into narrow dinuclear metallacycles that can trap the diatom while electrons from an externally bound group 1 metal, and protons or silanes, are added, enabling dinitrogen to be functionalized with modest but catalytic yields of six equivalents of secondary silylamine per molecule at ambient temperature and pressure.
Published: 2020
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158. Reactivity of a Molecular Calcium Hydride Cation ([CaH]

Author: Danny, Schuhknecht, Thomas P, Spaniol, Yan, Yang, Laurent, Maron, and Jun, Okuda
Abstract: The hydride ligand in the cationic calcium hydride supported by a NNNN-type macrocycle, [(Me
Published: 2020

159. Synthesis and versatile reactivity of scandium phosphinophosphinidene complexes

Author: Karl N. McCabe, Xuebing Leng, Li Xiang, Laurent Maron, Yaofeng Chen, Bin Feng, Shanghai Institute of Organic Chemistry - Chinese Academy of Sciences, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Science, General Physics and Astronomy, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Article, Theoretical chemistry, General Biochemistry, Genetics and Molecular Biology, Coordination complex, Metal, Transition metal, Reactivity (chemistry), Scandium, lcsh:Science, chemistry.chemical_classification, Multidisciplinary, 010405 organic chemistry, Chemistry, Ligand, General Chemistry, Coordination chemistry, 0104 chemical sciences, Crystallography, Phosphinidene, visual_art, visual_art.visual_art_medium, lcsh:Q, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Inorganic chemistry
Abstract: M=E/M≡E multiple bonds (M = transition metal, E = main group element) are of significant fundamental scientific importance and have widespread applications. Expanding the ranges of M and E represents grand challenges for synthetic chemists and will bring new horizons for the chemistry. There have been reports of M=E/M≡E multiple bonds for the majority of the transition metals, and even some actinide metals. In stark contrast, as the largest subgroup in the periodic table, rare-earth metals (Ln) were scarcely involved in Ln=E/Ln≡E multiple bonds. Until recently, there were a few examples of rare-earth monometallic alkylidene, imido and oxo complexes, featuring Ln=C/N/O bonds. What are in absence are rare-earth monometallic phosphinidene complexes with Ln=P bonds. Herein, we report synthesis and structure of rare-earth monometallic phosphinidene complexes, namely scandium phosphinophosphinidene complexes. Reactivity of scandium phosphinophosphinidene complexes is also mapped out, and appears to be easily tuned by the supporting ligand., Rare-earth monometallic phosphinidene complexes have been elusive synthetic targets. Here, the authors describe the synthesis and tunable reactivity of two scandium phosphinophosphinidene complexes containing very unusual Sc-P multiple bonds.
Published: 2020
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160. Uranium Metallocene Azides, Isocyanates, and Their Borane-Capped Lewis Adducts

Author: John Arnold, Michael A. Boreen, Trevor D. Lohrey, Stephan Hohloch, Laurent Maron, Fabian A. Watt, Karl N. McCabe, Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Paderborn, Freie Universität Berlin, and Universität Innsbruck [Innsbruck]
Subjects: 010405 organic chemistry, Ligand, Borane, 010402 general chemistry, Cyanate, 01 natural sciences, Medicinal chemistry, Isocyanate, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Cyclopentadienyl complex, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Azide, Physical and Theoretical Chemistry, Linkage isomerism, Metallocene
Abstract: Uranium(IV) metallocene complexes (CpiPr4)2U(N3)2 (1-N3), (CpiPr)2U(NCO)2 (1-NCO), and (CpiPr4)2U(OTf)2 (1-OTf) containing the bulky CpiPr4 ligand (CpiPr4 = tetra(isopropyl)cyclopentadienyl) were prepared directly from reactions between (CpiPr4)2UI2 or (CpiPr4)2UI and corresponding pseudohalide salts. The mixed-ligand complex (CpiPr4)2U(N3)(OTf) (1-N3-OTf) was isolated after heating a 1:1 mixture of 1-N3 and 1-OTf. The coordination of 1 equiv B(C6F5)3 to 1-N3 produced the borane-capped azide (CpiPr4)2U(N3)[(μ-η1:η1-N3)B(C6F5)3] (2-N3), while the reaction of 1 equiv B(C6F5)3 with 1-NCO yielded (CpiPr4)2U(NCO)[(μ-η1:η1-OCN)B(C6F5)3] (2-NCO) in which the borane-capped cyanate ligand had rearranged to become O-bound to uranium. The reaction of (CpiPr4)2UI and NaOCN led to the isolation of the uranium(III) cyanate-bridged "molecular square" [(CpiPr4)2U(μ-η1:η1-OCN)]4 (3-OCN). Cyclic voltammetry and UV-vis spectroscopy revealed small differences in the electronic properties between azide and isocyanate complexes, while X-ray crystallography showed nearly identical solid-state structures, with the most notable difference being the geometry of borane coordination to the azide in 2-N3 versus the cyanate in 2-NCO. Reactivity studies comparing 3-OCN to the azide analogue [(CpiPr4)2U(μ-η1:η1-N3)]4 (3-N3) demonstrated significant differences in the chemistry of cyanates and azides with trivalent uranium. A computational analysis of 1-NCO, 1-N3, 2-NCO, and 2-N3 has provided a basis for understanding the energetic preference for specific linkage isomers and the effect of the B(C6F5)3 coordination on the bonding between uranium, azide, and isocyanate ligands.
Published: 2020
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161. Activation of Ethylene by N-Heterocyclic Carbene Coordinated Magnesium(I) Compounds

Author: Iskander Douair, K. Yuvaraj, Cameron Jones, Laurent Maron, School of Chemistry, Monash University [Clayton], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Ethylene, 010405 organic chemistry, Magnesium, Organic Chemistry, chemistry.chemical_element, NacNac, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Carbene, Stoichiometry
Abstract: Reactions of a series of magnesium(I) compounds with ethylene, in the presence of an N-heterocyclic carbene (NHC), have been explored. Treating [{(Mes Nacnac)Mg}2 ] (Mes Nacnac=[HC(MeCNMes)2 ]- , Mes=mesityl) with an excess of ethylene in the presence of two equivalents of :C{(MeNCMe)2 } (TMC) leads to the formal reductive coupling of ethylene, and formation of the 1,2-dimagnesiobutane complex, [{(Mes Nacnac)(TMC)Mg}2 (μ-C4 H8 )]. In contrast, when the reaction is repeated in the presence of three equivalents of TMC, a mixture of the β-diketiminato magnesium ethyl, [(Mes Nacnac)(TMC)MgEt], and the NHC coordinated magnesium diamide, [(Mes Nacnac-H )Mg(TMC)2 ], results. Four related products, [(Ar Nacnac)(TMC)MgEt] (Ar=2,6-dimethylphenyl (Xyl) or 2,6-diisopropylphenyl (Dip)) and [(Ar Nacnac-H )Mg(TMC)2 ] (Ar=Xyl or Dip), were similarly synthesised and crystallographically characterized. Computational studies have been employed to investigate the mechanisms of the two observed reaction types, which appear dependent on the substitution pattern of the magnesium(I) compound, and the stoichiometric equivalents of TMC used in the reactions.
Published: 2020
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162. Alkalimetallamid‐stabilisierte Titancarben‐Komplexe

Author: Khai-Nghi Truong, Thomas P. Spaniol, Jun Okuda, Laurent Maron, Hassan Osseili, and Ulli Englert
Subjects: Chemistry, General Medicine
Published: 2019
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163. Titanium Carbene Complexes Stabilized by Alkali Metal Amides

Author: Hassan Osseili, Ulli Englert, Laurent Maron, Khai-Nghi Truong, Thomas P. Spaniol, and Jun Okuda
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Ligand, chemistry.chemical_element, General Chemistry, 010402 general chemistry, Alkali metal, 01 natural sciences, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Nucleophile, Polymer chemistry, Wittig reaction, Benzophenone, Carbene, Alkyl, Titanium
Abstract: Facile α-H elimination from tetrakis(trimethylsilylmethyl)titanium precursors to give adducts of (alkylidene)bis(alkyl)titanium complexes is induced by light alkali metal amides of the NNNN-type macrocyclic anionic ligand Me3 TACD [(Me3 TACD)H=1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane]. In the crystal, the alkali metal interacts with the carbene carbon atom or with the CH2 group of the trimethylsilymethyl ligand. The nucleophilic character of the carbene carbon atom was shown by the reaction with benzophenone and terminal acetylenes.
Published: 2019
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164. Monomeric thorium dihydrido complexes: versatile precursors to actinide metallacycles

Author: Laurent Maron, Iker del Rosal, Yang Wang, Guorui Qin, Jianhua Cheng, Xianghui Shi, Shanghai Institute of Materia Medica - Chinese Academy of Sciences [Shanghai], University of Chinese Academy of Sciences [Beijing] (UCAS), Institute of Computing Technology Chinese Academy of Sciences, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), National Natural Science Foundation of China [21672202], and HPC's CALcul en Midi-Pyrenees (CALMIP-EOS grant) [1415]
Subjects: Addition reaction, 010405 organic chemistry, Metals and Alloys, Thorium, chemistry.chemical_element, General Chemistry, Actinide, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, Monomer, chemistry, Materials Chemistry, Ceramics and Composites, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: International audience; The monomeric actinide dihydrido complex [(Cp-Ar*)(Cp*)ThH2(THF)] (2) bearing the super-bulky penta-arylcyclopentadienyl (Cp-Ar* = C5Ar*(5), Ar* = 3,5-Bu-t(2)-C6H3) and pentamethylcyclopentadienyl (Cp* = C5Me5) ligands was obtained for the first time. Complex 2 underwent unique Th-H addition reactions with various unsaturated compounds to afford the corresponding five-membered metallacycles, including the first example of actinide metallacyclopentyne [(Cp-Ar*)(Cp*)Th(PhCH-CC-CHPh)] (4).
Published: 2019
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165. Reduction of 1,3,5,7-cyclooctatetraene by a molecular calcium hydride: an even electron polarised insertion/deprotonation mechanism

Author: Mary F. Mahon, Emma Richards, Chiara Dinoi, Laurent Maron, Andrew S. S. Wilson, Michael S. Hill, Department of Chemistry [Bath], University of Bath [Bath], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Chemistry [Cardiff], Cardiff University, and EPSRC [EP/N014456/1, EP/R020752/1] Funding Source: UKRI
Subjects: Calcium hydride, 010405 organic chemistry, Hydride, Metals and Alloys, General Chemistry, Annulene, 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, Cyclooctatetraene, Deprotonation, chemistry, Reagent, Materials Chemistry, Ceramics and Composites, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Derivative (chemistry)
Abstract: Reaction of a dimeric β-diketiminato calcium hydride with 1,3,5,7-cyclooctatetraene enables two electron aromatisation of the [8]annulene to provide an inverse sandwich dicalcium cyclooctatetraenyl derivative. This reactivity does not proceed through sequential single electron transfer but via a consecutive polarised Ca-H/C[double bond, length as m-dash]C insertion and deprotonation pathway that occurs at the intact dimeric hydride reagent.
Published: 2019
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166. Transition metal-induced dehydrogenative coupling of zinc hydrides

Author: Xin Xu, Shengjie Jiang, Laurent Maron, Min Chen, Soochow University, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), National Natural Science Foundation of China [21871204, 21502132], 1000-Youth Talents Plan, Jiangsu Specially-Appointed Professor Plan, PAPD, and Project of Scientific and Technologic Infrastructure of Suzhou [SZS201708]
Subjects: inorganic chemicals, 010405 organic chemistry, chemistry.chemical_element, Zinc, 010402 general chemistry, 01 natural sciences, Oxidative addition, Reductive elimination, 0104 chemical sciences, Inorganic Chemistry, Nickel, chemistry, Transition metal, Covalent bond, Reagent, Polymer chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Palladium
Abstract: International audience; The reaction of terminal zinc hydrides with palladium(0) species afforded an unprecedented [eta(2)-Zn2Pd] trimetallic complex through the reductive elimination of H-2. In contrast, the reaction of zinc hydrides with a nickel(0) reagent gave sigma-Zn-H coordination complexes with no direct Zn-Zn bonding. Computational studies indicated that an oxidative addition/reductive elimination process at the palladium center might be responsible for the formation of a covalent Zn-Zn bond.
Published: 2019
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167. Magnesium hydride alkene insertion and catalytic hydrosilylation

Author: Laurent Maron, Michael S. Hill, Chiara Dinoi, Mary F. Mahon, Lucia Garcia, Department of Chemistry [Bath], University of Bath [Bath], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), EPSRC (UK) [EP/N014456/1], and EPSRC [EP/N014456/1] Funding Source: UKRI
Subjects: chemistry.chemical_classification, Chemistry(all), Double bond, 010405 organic chemistry, Chemistry, Hydride, Magnesium, Alkene, Hydrosilylation, Magnesium hydride, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, chemistry.chemical_compound, Salt metathesis reaction, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Norbornene
Abstract: The dimeric β-diketiminato magnesium hydride, [(BDI)MgH]2, reacts at 80 °C with the terminal alkenes, 1-hexene, 1-octene, 3-phenyl-1-propene and 3,3-dimethyl-butene to provide the respective n-hexyl, n-octyl, 3-phenylpropyl and 3,3-dimethyl-butyl magnesium organometallics. The facility for and the regiodiscrimination of these reactions are profoundly affected by the steric demands of the alkene reagent. Reactions with the phenyl-substituted alkenes, styrene and 1,1-diphenylethene, require a more elevated temperature of 100 °C with styrene providing a mixture of the 2-phenylethyl and 1-phenylethyl products over 7 days. Although the reaction with 1,1-diphenylethene yields the magnesium 1,1-diphenylethyl derivative as the sole reaction product, only 64% conversion was achieved over a 21 day timeframe. Reactions with the α,ω-dienes, 1,5-hexadiene and 1,7-octadiene, provided divergent results. The initial 5-alkenyl magnesium reaction product of the shorter chain diene undergoes 5-exo-trig cyclisation via intramolecular carbomagnesiation to provide a cyclopentylmethyl derivative, which was shown by X-ray diffraction analysis to exist as a three-coordinate monomer. In contrast, 1,7-octadiene provided a mixture of two compounds, a magnesium oct-7-en-1-yl derivative and a dimagnesium-octane-1,4-diide, as a result of single or two-fold activation of the terminal C[double bond, length as m-dash]C double bonds. The magnesium hydride was unreactive towards internal alkenes apart from the strained bicycle, norbornene, allowing the characterisation of the resultant three-coordinate magnesium norbornyl derivative by X-ray diffraction analysis. Computational analysis of the reaction between [(BDI)MgH]2 and 1-hexene using density functional theory (DFT) indicated that the initial Mg-H/C[double bond, length as m-dash]C insertion process is rate determining and takes place at the intact magnesium hydride dimer. This exothermic reaction (ΔH = -14.1 kcal mol-1) traverses a barrier of 18.9 kcal mol-1 and results in the rupture of the dinuclear structure into magnesium alkyl and hydride species. Although the latter three-coordinate hydride derivative may be prone to redimerisation, it can also provide a further pathway to magnesium alkyl species through its direct reaction with a further equivalent of 1-hexene, which occurs via a lower barrier of 15.1 kcal mol-1. This Mg-H/C[double bond, length as m-dash]C insertion reactivity provides the basis for the catalytic hydrosilylation of terminal alkenes with PhSiH3, which proceeds with a preference for the formation of the anti-Markovnikov organosilane product. Further DFT calculations reveal that the catalytic reaction is predicated on a sequence of Mg-H/C[double bond, length as m-dash]C insertion and classical Si-H/Mg-C σ-bond metathesis reactions, the latter of which, with a barrier height of 24.9 kcal mol-1, is found to be rate determining.
Published: 2019
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168. Selective oxo ligand functionalisation and substitution reactivity in an oxo/catecholate-bridged U

Author: Bradley E, Cowie, Iskander, Douair, Laurent, Maron, Jason B, Love, and Polly L, Arnold
Subjects: Chemistry
Abstract: A UIV/UIV “Pacman” complex exhibits facile oxo-ligand functionalisation and substitution reactivity, owing to a bridging catecholate ligand that enhances the μ-oxo nucleophilicity and stabilises the resulting products., The oxo- and catecholate-bridged UIV/UIV Pacman complex [{(py)UIVOUIV(μ-O2C6H4)(py)}(LA)] A (LA = a macrocyclic “Pacman” ligand; anthracenylene hinge between N4-donor pockets, ethyl substituents on meso-carbon atom of each N4-donor pocket) featuring a bent UIV–O–UIV oxo bridge readily reacts with small molecule substrates to undergo either oxo-atom functionalisation or substitution. Complex A reacts with H2O or MeOH to afford [{(py)UIV(μ-OH)2UIV(μ-O2C6H4)(py)}(LA)] (1) and [{(py)UIV(μ-OH)(μ-OMe)UIV(μ-O2C6H4)(py)}(LA)] (2), respectively, in which the bridging oxo ligand in A is substituted for two bridging hydroxo ligands or one bridging hydroxo and one bridging methoxy ligand, respectively. Alternatively, A reacts with either 0.5 equiv. of S8 or 4 equiv. of Se to provide [{(py)UIV(μ-η2:η2-E2)UIV(μ-O2C6H4)(py)}(LA)] (E = S (3), Se (4)) respectively, in which the [E2]2– ion bridges the two UIV centres. To the best of our knowledge, complex A is the first example of either a d- or f-block bimetallic μ-oxo complex that activates elemental chalcogens. Complex A also reacts with XeF2 or 2 equiv. of Me3SiCl to provide [{(py)UIV(μ-X)2UIV(μ-O2C6H4)(py)}(LA)] (X = F (5), Cl (6)), in which the oxo ligand has been substituted for two bridging halido ligands. Reacting A with either XeF2 or Me3SiCl in the presence of O(Bcat)2 at room temperature forms [{(py)UIV(μ-X)(μ-OBcat)UIV(μ-O2C6H4)(py)}(LA)] (X = F (5A), Cl (6A)), which upon heating to 80 °C is converted to 5 and 6, respectively. In order to probe the importance of the bent UIV–O–UIV motif in A on the observed reactivity, the bis(boroxido)-UIV/UIV complex, [{(py)(pinBO)UIVOUIV(OBpin)(py)}(LA)] (B), featuring a linear UIV–O–UIV bond angle was treated with H2O and Me3SiCl. Complex B reacts with two equiv. of either H2O or Me3SiCl to provide [{(py)HOUIVOUIVOH(py)}(LA)] (7) and [{(py)ClUIVOUIVCl(py)}(LA)] (8), respectively, in which reactions occur preferentially at the boroxido ligands, with the μ-oxo ligand unchanged. The formal UIV oxidation state is retained in all of the products 1–8, and selective reactions at the bridging oxo ligand in A is facilitated by: (1) its highly nucleophilic character which is a result of a non-linear UIV–O–UIV bond angle causing an increase in U–O bond covalency and localisation of the lone pairs of electrons on the μ-oxo group, and (2) the presence of the bridging catecholate ligand, which destabilises a linear oxo-bridging geometry and stabilises the resulting products.
Published: 2020

169. A tetranuclear nickel cluster isolated in multiple high-valent states

Author: Iskander Douair, Gabriel Ménard, Laurent Maron, Guang Wu, Samuel I. Jacob, Chemistry and Biochemistry [Santa Barbara] (CCS-UCSB), College of Creative Studies [Santa-Barbara] (CCS-UCSB), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC)-University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Metals and Alloys, chemistry.chemical_element, General Chemistry, Electrochemistry, Catalysis, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Nickel, Crystallography, chemistry, Materials Chemistry, Ceramics and Composites, Cluster (physics), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: We report a series of high-valent tetranuclear nickel clusters isolated from the chemical oxidation of an all Ni(II) ([Ni4]) neutral cluster. Electrochemical analysis of [Ni4] reveals three reversible sequential oxidations at 0.248 V (1e−), 0.678 V (1e−), and 0.991 V (2e−) vs. Fc/Fc+ corresponding to mono-, di-, and tetra-oxidized species, [Ni4]+, [Ni4]2+, [Ni4]4+, respectively. Using spectroscopic, crystallographic, magnetometric, and computational techniques, we assign the primary loci of oxidations to the Ni centers in each case, thus resulting in the isolation of the first tetranuclear all-Ni(III) cluster, [Ni4]4+.
Published: 2020
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170. Cover Feature: Hydrogen Isotope Exchange Catalyzed by Ru Nanocatalysts: Labelling of Complex Molecules Containing N ‐Heterocycles and Reaction Mechanism Insights (Chem. Eur. J. 22/2020)

Author: Sébastien Garcia-Argote, Iker del Rosal, Philippe Lesot, Donia Bouzouita, Laurent Maron, Simon Tricard, Sophie Feuillastre, Marie Certiat, Romuald Poteau, Elodie Marcon, Bruno Chaudret, David-Alexandre Buisson, Viktor Pfeifer, Alberto Palazzolo, Grégory Pieters, 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), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), 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 National de la Recherche Scientifique (CNRS), Modélisation Physique et Chimique (LPCNO), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Department of Chemistry and Chemical Biology [Harvard], Harvard University [Cambridge], Laboratoire de Physique Quantique (LPQ), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-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), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Harvard University, and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Reaction mechanism, 010405 organic chemistry, Chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Hydrogen isotope, Organic Chemistry, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Combinatorial chemistry, Catalysis, Nanomaterial-based catalyst, 0104 chemical sciences, Deuterium, Labelling, Molecule, Tritium, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2020
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171. Two-Electron Oxidative Atom Transfer at a Homoleptic, Tetravalent Uranium Complex

Author: John Bacsa, Natalie T. Rice, Karl McCabe, Laurent Maron, Henry S. La Pierre, Georgia Institute of Technology [Atlanta], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chemistry, chemistry.chemical_element, General Chemistry, Oxidative phosphorylation, Electron, Nitrous oxide, Uranium, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Crystallography, Colloid and Surface Chemistry, Atom, Azide, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Homoleptic
Abstract: A tetrahomoleptic, pseudotetrahedral U4+ imidophosphorane complex, [U(NP(pip)3)4], 1-U(PN), is reported. This complex can be oxidized by two electrons with either mesityl azide or nitrous oxide. Th...
Published: 2020
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172. Monomeric Rare-Earth Metal Silyl-Thiophosphinoyl-Alkylidene Complexes: Synthesis, Structure, and Reactivity

Author: Yan Yang, Laurent Maron, Li Xiang, Yaofeng Chen, Weiqing Mao, Xuebing Leng, Jian Fang, Chen Wang, Shanghai Institute of Organic Chemistry (SIOC), Chinese Academy of Sciences [Beijing] (CAS), Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), National Natural Science Foundation of China [21732007, 21325210], Strategic Priority Research Program of the Chinese Academy of Sciences [XDB20000000], Program of Shanghai Academic Research Leader [18XD1404900], and HPCs CALcul en Midi-Pyrenees (CALMIP-EOS grant) [1415]
Subjects: Reaction mechanism, 010405 organic chemistry, Chemistry, Ligand, Metal ions in aqueous solution, Organic Chemistry, General Chemistry, 010402 general chemistry, Triple bond, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, Metal, chemistry.chemical_compound, visual_art, visual_art.visual_art_medium, Phenyl group, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], density functional calculations, insertion, multiple bonds, rare earths, X-ray diffraction, Bond cleavage
Abstract: International audience; A series of monomeric rare-earth metal silyl-thiophosphinoyl-alkylidene complexes [LLn{C(SiR3)PPh2S}] (5: Ln=Lu, R=Me; 6: Ln=Lu, R=Ph; 7: Ln=Y, R=Me; 8: Ln=Y, R=Ph; 9: Ln=Sm, R=Ph; 10: Ln=Sm, R=Me; 11: Ln=La, R=Ph; L=[MeC(NDIPP)CHC(Me)(NCH2CH2N(Me)(2))](-), DIPP=2,6-(iPr)(2)C6H3) have been synthesized and structurally characterized. The influences of rare-earth metal ions, ancillary ligands, and alkylidene groups on the reactivity of complexes 5-11 and the related scandium complexes [LSc{C(SiR3)PPh2S}] (1: R=Me; 2: R=Ph) and [LSc{C(SiR3)PPh2S}] (3: R=Me; 4: R=Ph; L=[MeC(NDIPP)CHC(Me)(NCH2CH2N(iPr)(2))](-)) have been studied. Reactions of these rare-earth metal alkylidene complexes with PhCN give four kinds of products, the formation of which is dependent on the rare-earth metal ions, ancillary ligands, and alkylidene groups of the complexes. In the reactions with tBuNC, unusual C-P bond cleavage of the alkylidene group and CC triple bond formation occur. Complexes 10 and 11 also react with PhSiH3 to form hydrides, which subsequently undergo Ln-H addition to the C=N bond of the ancillary ligand L. DFT calculations have been used to analyze the bonding in complex 10, which exhibits a polarized three centers Sm-C-P interaction, and to rationalize the reactivity by computing reaction mechanisms. The difference in reactivity of PhCN and tBuNC is due to the electron density delocalization that is enabled by the phenyl group rather than the tBu group.
Published: 2018
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173. Are Sc-C and Sc-P Bonds Reactive in Scandium Phosphinoalkylidene Complex? Insights on a Versatile Reactivity

Author: Xuebing Leng, Carlos Alvarez Lamsfus, Laurent Maron, Li Xiang, Yaofeng Chen, and Weiqing Mao
Subjects: chemistry, 010405 organic chemistry, Phosphorus, chemistry.chemical_element, Reactivity (chemistry), General Chemistry, Scandium, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Multiple bonds, 0104 chemical sciences
Published: 2018
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174. Dianionic Carbon-Bridged Scandium-Copper/Silver Heterobimetallic Complexes: Synthesis, Bonding, and Reactivity

Author: Chen Wang, Jian Fang, Xuebing Leng, Li Xiang, Yan Yang, Laurent Maron, Yaofeng Chen, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Shanghai Institute of Organic Chemistry (SIOC), Chinese Academy of Sciences [Beijing] (CAS), National Natural Science Foundation of China [21325210, 21732007], and Strategic Priority Research Program of the Chinese Academy of Sciences [XDB20000000]
Subjects: chemistry.chemical_classification, Addition reaction, Double bond, 010405 organic chemistry, Organic Chemistry, chemistry.chemical_element, General Chemistry, Reaction intermediate, 010402 general chemistry, 01 natural sciences, Copper, Catalysis, 0104 chemical sciences, Metal, Transmetalation, chemistry, visual_art, Polymer chemistry, visual_art.visual_art_medium, alkylidenes, cooperative effects, density functional calculations, heterometallic, scandium, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Scandium
Abstract: International audience; Alkylidene-bridged scandium-copper/silver heterobimetallic complexes were synthesized and structurally characterized. The complexes contain different Sc-C and M-C (M=Cu-I, Ag-I) bonds. The reactivity of the scandium-copper heterobimetallic complex was also studied, which reveals that the heterobimetallic complex is a reaction intermediate for the transmetalation of akylidene group from Sc-III to Cu-I. The scandium-copper heterobimetallic complex also undergoes an addition reaction with CO, resulting in the formation of a new C=C double bond. DFT calculations were used to study the bonding and the subsequent reactivity with CO of the scandium-copper heterobimetallic complex. It clearly demonstrates a cooperative effect between the two metal centers through the formation of a direct Sc center dot center dot center dot Cu interaction that drives the reactivity with CO.
Published: 2018
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175. Aqueous Solvation of SmI3: A Born–Oppenheimer Molecular Dynamics Density Functional Theory Cluster Approach

Author: J. I. Amaro-Estrada, Laurent Maron, Alejandro Ramírez-Solís, Jorge Hernández-Cobos, Universidad Autonoma del Estado de Morelos (UAEM), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), CONACYT Basic Science project [253679], DGAPA-UNAM, and DGAPA-UNAM [IG100416]
Subjects: Aqueous solution, 010405 organic chemistry, Chemistry, Born–Oppenheimer approximation, Solvation, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, symbols.namesake, Molecular dynamics, Chemical physics, symbols, Cluster (physics), Molecule, Density functional theory, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract: International audience; We report the results of Born-Oppenheimer molecular dynamics (BOMD) simulations on the aqueous solvation of the SmI3 molecule and of the bare Sm3+ cation at room temperature using the cluster microsolvation approach including 37 and 29 water molecules, respectively. The electronic structure calculations were done using the M062X hybrid exchange-correlation functional in conjunction with the 6-31G** basis sets for oxygen and hydrogen. For the iodine and samarium atoms, the Stuttgart-Koln relativistic effective-core potentials were utilized with their associated valence basis sets. When SmI3 is embedded in the microsolvation environment, we find that substitution of the iodine ions by water molecules around Sm(III) cannot be achieved due to an insufficient number of explicit water molecules to fully solvate the four separate metal and halogen ions. Therefore, we studied the solvation dynamics of the bare Sm3+ cation with a 29-water molecule model cluster. Through the Sm-O radial distribution function and the evolution of the Sm-O distances, the present study yields a very tightly bound first rigid Sm(III) solvation shell from 2.3 to 2.9 angstrom whose integration leads to a coordination number of 9 water molecules and a second softer solvation sphere from 3.9 to 5 angstrom with 12 water molecules. No water exchange processes were found. The theoretical EXAFS spectrum is in excellent agreement with the experimental spectrum for Sm(III) in liquid water. The strong differences between the solvation patterns of Sm(III) vs Sm(II) are discussed in detail.
Published: 2018
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176. Cover Feature: [(Me 6 TREN)MgOCHPh 2 ][B(C 6 F 5 ) 4 ]: A Model Complex to Explore the Catalytic Activity of Magnesium Alkoxides in Ketone Hydroboration (Eur. J. Inorg. Chem. 45/2021)

Author: Sumanta Banerjee, Raju Chambenahalli, Yan Yang, Ankur, Laurent Maron, R Kannan, and Ajay Venugopal
Subjects: Inorganic Chemistry, chemistry.chemical_classification, Hydroboration, Ketone, chemistry, Feature (computer vision), Magnesium, chemistry.chemical_element, Cover (algebra), Medicinal chemistry, Catalysis
Published: 2021
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177. Kinetic stabilisation of a molecular strontium hydride complex using an extremely bulky amidinate ligand

Author: Thomas Sutcliffe, Laurent Maron, Caspar N. de Bruin-Dickason, Cameron Jones, Glen B. Deacon, Carlos Alvarez Lamsfus, School of Chemistry, Monash University, 3800 Clayton, Victoria (Australie), Monash University [Clayton], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Australian Research Council, U.S. Air Force Asian Office of Aerospace Research and Development [FA2386-18-1-0125], and Alexander von Humboldt Foundation
Subjects: Strontium, Alkaline earth metal, 010405 organic chemistry, Ligand, Chemistry, Hydride, Magnesium hydride, Metals and Alloys, chemistry.chemical_element, General Chemistry, 010402 general chemistry, Kinetic energy, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystallography, chemistry.chemical_compound, Materials Chemistry, Ceramics and Composites, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: International audience; Two extremely bulky amidinate ligands, [RC{N(Dip)}{N(Ar-dagger)}](-) (Dip = 2,6-diisopropylphenyl; Ar-dagger = C6H2{C(H)Ph-2}(2)Pr-i-2,6,4; R = 1-adamantyl (L-Ad), tert-butyl (L-tBu)) have been developed and utilised for the kinetic stabilisation of the strontium and magnesium hydride complexes, [(LSr)-Sr-Ad(mu-H)](2) and [(LMg)-Mg-R(mu-H)](2) (R = Ad or Bu-t). The former represents the missing link in the series of dimeric systems, [LAe(mu-H)](2) (Ae = alkaline earth metal). The structure and bonding of the complexes have been studied by crystallographic, spectroscopic and computational techniques.
Published: 2018
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178. Chemical structure and bonding in a thorium(<scp>iii</scp>)–aluminum heterobimetallic complex

Author: Laurent Maron, Stefan G. Minasian, R. David Britt, Alexandra C. Brown, David K. Shuh, John Arnold, Alison B. Altman, Trevor D. Lohrey, Guodong Rao, Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Earth Sciences Division (ESD), Lawrence Berkeley National Lab, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences Heavy Element Chemistry Program of the U.S. Department of Energy (DOE) at LBNL [DE-AC02-05CH11231], NIH [1R35GM126961-01], Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium [DE-NA0003180, DE-NA0000979], U.S. DOE Office of Science User Facility [DE-AC02-05CH11231], DOE Integrated University Program Fellowships at the University of California, Berkeley, and Goldwater Foundation
Subjects: 010405 organic chemistry, Chemistry, General Chemistry, Electronic structure, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, 3. Good health, law.invention, Delocalized electron, Crystallography, Unpaired electron, Transition metal, law, Chemical Sciences, Molecule, Density functional theory, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Electron paramagnetic resonance, Valence electron
Abstract: We describe the syntheses of [Th(iii)]–[Al] and [U(iii)]–[Al] bimetallics that demonstrate An→Al interactions where the actinide behaves as an electron donor., Thorium sits at a unique position on the periodic table. On one hand, there is little evidence that its 5f orbitals engage in bonding as they do in other early actinides; on the other hand, its chemistry is distinct from Lewis acidic transition metals. To gain insight into the underlying electronic structure of Th and develop trends across the actinide series, it is useful to study Th(iii) and Th(ii) systems with valence electrons that may engage in non-electrostatic metal–ligand interactions, although only a handful of such systems are known. To expand the range of low-valent compounds and gain deeper insight into Th electronic structure, we targeted actinide bimetallic complexes containing metal–metal bonds. Herein, we report the syntheses of Th–Al bimetallics from reactions between a di-tert-butylcyclopentadienyl supported Th(iv) dihalide (Cp‡2ThCl2) and an anionic aluminum hydride salt [K(H3AlC(SiMe3)3) (1)]. Reduction of the [Th(iv)](Cl)–[Al] product resulted in a [Th(iii)]–[Al] complex [Cp‡2Th(μ-H3)AlC(SiMe3)3 (4)]. The U(iii) analogue [Cp‡2U(μ-H3)AlC(SiMe3)3 (5)] could be synthesized directly from a U(iii) halide starting material. Electron paramagnetic resonance studies on 4 demonstrate hyperfine interactions between the unpaired electron and the Al atom indicative of spin density delocalization from the Th metal center to the Al. Density functional theory and atom in molecules calculations confirmed the presence of An→Al interactions in 4 and 5, which represents the first examples of An→M interactions where the actinide behaves as an electron donor.
Published: 2018
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179. Small molecule activation with divalent samarium triflate: a synergistic effort to cleave O2

Author: Elisa Louyriac, Grégory Nocton, Carine Clavaguéra, Mathieu Xémard, Laurent Maron, and Marie Cordier
Subjects: chemistry.chemical_classification, Lanthanide, 010405 organic chemistry, Salt (chemistry), chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Small molecule, 0104 chemical sciences, Divalent, Inorganic Chemistry, Samarium, Samarium triflate, chemistry, Cleave, Reductive cleavage, Polymer chemistry
Abstract: The divalent samarium triflate salt does not react with CO2 or water, but does react with traces of O2 or N2O to form a tetrameric bis-oxo samarium motif. The reaction with O2 is a 4e− reductive cleavage where the electrons are coming from four different samarium centers. This highlights a rare synergistic effect for cleaving O2, which has no precedent in divalent lanthanide complexes. Additionally, the addition of CO2 to the tetrameric bis-oxo intermediate leads to the formation of a tetrameric bis-carbonate samarium triflate. Thus, the concomitant reaction of CO2 with traces of O2 leads to the same bis-carbonate tetrameric assembly.
Published: 2018
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180. Reductive Disproportionation of CO2 with Bulky Divalent Samarium Complexes

Author: Violaine Goudy, Augustin Braun, Grégory Nocton, Christos E. Kefalidis, Mathieu Xémard, Laurent Maron, Marie Cordier, Carine Clavaguéra, Elisa Louyriac, Louis Ricard, Maxime Tricoire, and Ludovic Castro
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Dimer, Organic Chemistry, Inorganic chemistry, chemistry.chemical_element, Disproportionation, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, 3. Good health, Divalent, Adduct, Inorganic Chemistry, Samarium, Solvent, chemistry.chemical_compound, chemistry, Pyridine, Physical and Theoretical Chemistry, Diethyl ether
Abstract: The base-free divalent samarium complex Cptt2Sm (1; Cptt = 1,3-(tBu)2(C5H3)) has been synthesized in diethyl ether by salt metathesis of SmI2. Crystals of 1 suitable for X-ray study have been obtained by sublimation at 116 °C under reduced pressure. The dissolution of 1 in thf and pyridine solution leads to the solvent adducts Cptt2Sm(thf)2 (3) and Cptt2Sm(py) (4), respectively, while drying 3 under reduced pressure yields CpttSm(thf) (5). The reaction of CO2 with the base-free divalent samarium complexes Cptt2Sm (1) and Cpttt2Sm (2; Cpttt =1,2,4-(tBu)3(C5H2)) leads to the clean formation of bridged carbonate samarium dimers [Cpttt2Sm]2(μ-CO3) (7) and [Cptt2Sm]2(μ-CO3) (8). This is indicative of the reductive disproportionation of CO2 in both cases with release of CO. This contrasts with the formation of the oxalate-bridged samarium dimer reported from the reaction of CO2 with the Cp*2Sm(thf)2 complex. Otherwise, the reaction with CO does not proceed with the bulky complexes, while traces of O2 have led t...
Published: 2017
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181. Formation of a Uranium-Bound η1-Cyaphide (CP–) Ligand via Activation and C–O Bond Cleavage of Phosphaethynolate (OCP–)

Author: Frank W. Heinemann, Christopher J. Hoerger, Laurent Maron, Elisa Louyriac, Hansjörg Grützmacher, and Karsten Meyer
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Chemistry, Stereochemistry, Ligand, Organic Chemistry, Center (category theory), chemistry.chemical_element, Salt (chemistry), Halide, Uranium, 010402 general chemistry, Metathesis, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Ion, Inorganic Chemistry, Physical and Theoretical Chemistry, Bond cleavage
Abstract: Reaction of the trivalent uranium complex [((Ad,MeArO)3N)U(DME)] with [Na(OCP)(dioxane)2.5] and 2.2.2-crypt yields the μ-oxo-bridged, diuranium complex [Na(2.2.2-crypt)][{((Ad,MeArO)3N)U(DME)}(μ-O){((Ad,MeArO)3N)U(CP)}] (1). Complex 1 features an asymmetric, dinuclear UIV–O–UIV core structure with a cyaphide (CP–) anion η1-CP bound to one of the U ions, and a κ2-O DME coordinated to the other. The CP– ligand is unprecedented in uranium chemistry and is formed through reductive C–O bond cleavage of the phosphaethynolate anion (OCP–). An analogous reaction was performed starting from the tetravalent uranium halide complex [((Ad,MeArO)3N)U(DME)(Cl)]. This salt metathesis approach with [Na(OCP)(dioxane)2.5] results in formation of the mononuclear complex [((Ad,MeArO)3N)U(DME)(OCP)] (2) with an OCP– anion bound to the uranium(IV) center via the oxygen atom in an η1-OCP fashion.
Published: 2017
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182. Synthesis and Reactivity of a Scandium Terminal Hydride: H2 Activation by a Scandium Terminal Imido Complex

Author: Xianghao Han, Carlos Alvarez Lamsfus, Laurent Maron, Yaofeng Chen, Weiqing Mao, Erli Lu, Li Xiang, and Xuebing Leng
Subjects: 010405 organic chemistry, Chemistry, Hydride, Organic Chemistry, chemistry.chemical_element, General Chemistry, 010402 general chemistry, Photochemistry, Metathesis, 01 natural sciences, Catalysis, 0104 chemical sciences, Metal, Terminal (electronics), visual_art, Polymer chemistry, visual_art.visual_art_medium, Reactivity (chemistry), Density functional theory, Scandium
Abstract: Dihydrogen is easily activated by a scandium terminal imido complex containing the weakly coordinated THF. The reaction proceeds via a 1,2-addition mechanism, which is distinct from -bond metathesis mechanism reported to date for rare-earth metal mediated H2 activation. This reaction yields a scandium terminal hydride, which is well structurally characterized, being the first one to date. The reactivity of this hydride is reported with unsaturated substrates, further enlightening the existence of the terminal hydride complex. Interestingly, the H2 activation can be reversible. DFT investigations further shed light on the mechanistic aspects of the reactivity of the scandium anilido-terminal hydride complex with PhNCS but also on the reversible H2 activation process.
Published: 2017
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183. Formation of Methane versus Benzene in the Reactions of (C 5 Me 5 ) 2 Th(CH 3 ) 2 with [CH 3 PPh 3 ]X (X=Cl, Br, I) Yielding Thorium‐Carbene or Thorium‐Ylide Complexes

Author: Pokpong Rungthanaphatsophon, Laurent Maron, Ludovic Castro, Justin R. Walensky, Andrew C. Behrle, Adrien Bathelier, and Charles L. Barnes
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Iodide, Inorganic chemistry, Thorium, chemistry.chemical_element, General Chemistry, General Medicine, 010402 general chemistry, 7. Clean energy, Medicinal chemistry, 01 natural sciences, Catalysis, Methane, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Ylide, Density functional theory, Phosphonium, Benzene, Carbene
Abstract: The reaction of (C5Me5)2Th(CH3)2 with the phosphonium salts [CH3PPh3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C5Me5)2Th[CHPPh3]X, rare terminal phosphorano-stabilized carbenes with thorium. These complexes feature the shortest thorium–carbon bonds (≈2.30 A) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C5Me5)2Th[κ2-(C,C′)-(CH2)(CH2)PPh2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH3PPh3]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene.
Published: 2017
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184. Calcium Hydride Cation [CaH]+Stabilized by an NNNN-type Macrocyclic Ligand: A Selective Catalyst for Olefin Hydrogenation

Author: Laurent Maron, Danny Schuhknecht, Carolin Lhotzky, Thomas P. Spaniol, and Jun Okuda
Subjects: Olefin fiber, Calcium hydride, 010405 organic chemistry, Chemistry, Inorganic chemistry, Cationic polymerization, chemistry.chemical_element, General Chemistry, Nuclear magnetic resonance spectroscopy, Calcium, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Hydrogenolysis, Macrocyclic ligand
Abstract: Reaction of dibenzyl calcium complex [Ca(Me4 TACD)(CH2 Ph)2 ], containing the neutral NNNN-type macrocyclic ligand Me4 TACD (Me4 TACD=1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane), with triphenylsilane gave the cationic dinuclear calcium hydride [Ca2 H2 (Me4 TACD)2 ](PhCHSiPh3 )2 which was characterized by NMR spectroscopy and single-crystal X-ray diffraction. The cation can be regarded as the ligand-stabilized dimeric form of hypothetical [CaH]+ . Hydrogenolysis of benzyl calcium cation [Ca(Me4 TACD)(CH2 Ph)(thf)]+ gave dicationic calcium hydrides [Ca2 H2 (Me4 TACD)2 ][BAr4 ]2 (Ar=C6 H4 -4-t Bu; C6 H3 -3,5-Me2 ) containing weakly coordinating anions. In THF, they catalyzed the isotope exchange of H2 and D2 to give HD and the hydrogenation of unactivated 1-alkenes.
Published: 2017
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185. Synthesis and Reactions of [Cp2Yb]2(μ-Me) and [Cp2Yb]2(μ-Me)(Me) and Related Yb2(II, III) and Yb2(III, III) Compounds

Author: Marc D. Walter, Phillip T. Matsunaga, Laurent Maron, Carol J. Burns, and Richard A. Andersen
Subjects: 010405 organic chemistry, Hydride, Stereochemistry, Organic Chemistry, Halide, Crystal structure, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Adduct, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, Reagent, Physical and Theoretical Chemistry, Ground state, Methyl group
Abstract: A new type of synthesis, referred to as oxidative methylation, is developed for [Cp*2Yb]2(μ-X) and [Cp*2Yb]2(μ-X)(X), where X = Me, using MeCu or Cp*2VMe as the methyl transfer reagent and Cp*2Yb. The synthetic methodology is extended to other X derivatives such as the halides and BH4. Reaction of [Cp*2Yb]2(μ-Me)(Me) and H2 yields the mixed-valent hydride [Cp*2Yb]2(μ-H), which eliminates H2 on gentle heating, forming Cp*2Yb. When Cp*2VX is replaced by Cp*2TiX, 1:1 adducts based upon Ti(III,d1) are isolated. The X-ray crystal structure of [Cp*2Yb](μ-Me)[TiCp*2] shows that the methyl group bridges the two different decamethylmetallocene fragments in a near-linear fashion, a geometry that is likely to resemble the transition state of the single-electron-transfer precursor complex. A CASSCF computational study on the mixed-valent hydride [Cp*2Yb]2(μ-H) shows that the ground state is a spin doublet in which the hydride forms a symmetric bridge to both Yb atoms. The three spins forming the ground-state doublet ...
Published: 2017
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186. Valorization of CO2: Preparation of 2-Oxazolidinones by Metal–Ligand Cooperative Catalysis with SCS Indenediide Pd Complexes

Author: Christos E. Kefalidis, Didier Bourissou, Blanca Martin-Vaca, Laurent Maron, Julien Monot, Paul Brunel, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Catalysis, Metal, chemistry.chemical_compound, Carbamic acid, [CHIM]Chemical Sciences, Organic chemistry, metal ligand cooperative catalysis, Alkyl, [PHYS]Physics [physics], chemistry.chemical_classification, 010405 organic chemistry, Chemistry, Ligand, General Chemistry, palladium, CO2 functionalization, Combinatorial chemistry, 0104 chemical sciences, Pincer movement, catalytic cycle, Catalytic cycle, visual_art, visual_art.visual_art_medium, proton shuttling, Palladium
Abstract: bibtex: ISI:000398986700049 bibtex\location:'1155 16TH ST, NW, WASHINGTON, DC 20036 USA',publisher:'AMER CHEMICAL SOC',type:'Article',affiliation:'Martin-Vaca, B; Bourissou, D (Reprint Author), Univ Toulouse, CNRS, UMR 5069, UPS,LHFA, 118 Route Narbonne, F-31062 Toulouse, France. Brunel, Paul; Monot, Julien; Martin-Vaca, Blanca; Bourissou, Didier, Univ Toulouse, CNRS, UMR 5069, UPS,LHFA, 118 Route Narbonne, F-31062 Toulouse, France. Kefalidis, Christos E.; Maron, Laurent, Univ Toulouse, CNRS, UMR 5215, INSA,UPS,LPCNO, 135 Ave Rangueil, F-31400 Toulouse, France.','author-email':'bmv@chimie.ups-tlse.fr dbouriss@chimie.ups-tlse.fr',da:'2018-12-05','doc-delivery-number':'ER7IS','funding-acknowledgement':'Centre National de la Recherche Scientifique; Universite de Toulouse; Agence Nationale de la Recherche [ANR CE6-CYCLOOP]; COST Action [CM1205 CARISMA]','funding-text':'This manuscript is in memory of Prof. Jose Barluenga. This work was supported financially by the Centre National de la Recherche Scientifique, the Universite de Toulouse, the Agence Nationale de la Recherche (ANR CE6-CYCLOOP), and the COST Action CM1205 CARISMA (Catalytic Routines for Small Molecule Activation). The authors are grateful to CalMip (CNRS, Toulouse, France) for calculation facilities. L.M. thanks the Institut Universitaire de France. Dr. J. Babinot is acknowledged for the preparation of substrates 1j,k.','journal-iso':'ACS Catal.','keywords-plus':'PALLADIUM PINCER COMPLEXES; CARBON-DIOXIDE INCORPORATION; N BOND FORMATION; CARBOXYLATIVE CYCLIZATION; EFFICIENT SYNTHESIS; PROPARGYLIC AMINES; ACETYLENIC AMINES; ATMOSPHERIC CO2; C-N; IONIC LIQUIDS','number-of-cited-references':'73',oa:'Bronze','orcid-numbers':'Kefalidis, Christos/0000-0002-1380-4337 Bourissou, Didier/0000-0002-0249-1769','research-areas':'Chemistry','researcherid-numbers':'Kefalidis, Christos/G-1067-2012','times-cited':'19','unique-id':'ISI:000398986700049','usage-count-last-180-days':'10','usage-count-since-2013':'32','web-of-science-categories':'Chemistry, Physical'\; International audience; The capture and utilization of CO, to prepare high value compounds is very attractive chemically and highly desirable socially. Indenediide-based Pd SCS pincer complexes are shown here to promote the carboxylative cyclization of propargylamines leading to 2-oxazolidinones under mild conditions (0.5-1 bar of CO2, DMSO, 40-80 degrees C, mol % Pd loading). The indenediide Pd complex is competitive with known catalysts. It proved successful for a wide range of propargylamines, including hitherto challenging substrates such as secondary propargylamines bearing tertiary alkyl groups at nitrogen, primary propargylamines, and propargylanilines. Thorough experimental (NMR) and computational (DFT) investigations were undertaken to gain mechanistic insights. Accordingly, (i) the resting state of the catalytic cycle is a Pd DMSO complex; (ii) the indenediide backbone and Pd center act in concert to activate the carbamic acid intermediate and promote its cyclization; (iii) proton shuttling is essential to lower the activation barriers of the initial amine carboxylation as well as of the proton transfers between the ligand backbone and the organic fragments at Pd.
Published: 2017
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187. Molecular and Electronic Structures of Eight-Coordinate Uranium Bipyridine Complexes: A Rare Example of a Bipy2– Ligand Coordinated to a U4+ Ion

Author: Frank W. Heinemann, Karsten Meyer, Michael W. Rosenzweig, and Laurent Maron
Subjects: 010405 organic chemistry, Chemistry, Ligand, Cryptand, Inorganic chemistry, chemistry.chemical_element, Electronic structure, Uranium, 010402 general chemistry, Electrochemistry, 01 natural sciences, 0104 chemical sciences, law.invention, Ion, Inorganic Chemistry, Crystallography, Bipyridine, chemistry.chemical_compound, law, Physical and Theoretical Chemistry, Electron paramagnetic resonance
Abstract: Reaction of trivalent [((Ad,tBuArO)3tacn)U] (1) with 2,2′-bipyridine (bipy) yields [((Ad,tBuArO)3tacn)U(bipy)] (2) and subsequent reduction of 2 with KC8 in the presence of Kryptofix222 furnishes [K(2.2.2-crypt)][((Ad,tBuArO)3tacn)U(bipy)] (3). Alternatively, complex 3 can be synthesized from 1 by addition of [K(bipy)] in the presence of the cryptand. New complexes 2 and 3 are characterized by a variety of spectroscopic, electrochemical, and magnetochemical methods, single-crystal X-ray diffraction, computational methods, and CHN elemental analysis. Structural analyses reveal a bipyridine radical (bipy•–) ligand in 2 and a dianionic (bipy2–) species in 3. Complex 3 represents a rare example of an isolated and unambiguously characterized bipy2– ligand coordinated to a uranium ion. The electronic structure assignments are supported by UV/vis/NIR and EPR spectroscopy, as well as SQUID magnetometry. The results of CASSCF calculations indicate multiconfigurational ground states for complexes 2 and 3. The elect...
Published: 2017
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188. Terminal Uranium(V)-Nitride Hydrogenations Involving Direct Addition or Frustrated Lewis Pair Mechanisms

Author: Ashley J. Wooles, Elisa Louyriac, Laurent Maron, Iskander Douair, Floriana Tuna, Benedict M. Gardner, Stephen T. Liddle, Erli Lu, Lucile Chatelain, University of Manchester [Manchester], Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and School of Chemistry [Manchester]
Subjects: Science, General Physics and Astronomy, chemistry.chemical_element, Triphenylborane, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Article, General Biochemistry, Genetics and Molecular Biology, Frustrated Lewis pair, Ammonia production, chemistry.chemical_compound, Hydrogenolysis, Reactivity (chemistry), Isostructural, lcsh:Science, Multidisciplinary, 010405 organic chemistry, General Chemistry, Actinide, Uranium, Coordination chemistry, 3. Good health, 0104 chemical sciences, chemistry, lcsh:Q, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Inorganic chemistry
Abstract: Despite their importance as mechanistic models for heterogeneous Haber Bosch ammonia synthesis from dinitrogen and dihydrogen, homogeneous molecular terminal metal-nitrides are notoriously unreactive towards dihydrogen, and only a few electron-rich, low-coordinate variants demonstrate any hydrogenolysis chemistry. Here, we report hydrogenolysis of a terminal uranium(V)-nitride under mild conditions even though it is electron-poor and not low-coordinate. Two divergent hydrogenolysis mechanisms are found; direct 1,2-dihydrogen addition across the uranium(V)-nitride then H-atom 1,1-migratory insertion to give a uranium(III)-amide, or with trimesitylborane a Frustrated Lewis Pair (FLP) route that produces a uranium(IV)-amide with sacrificial trimesitylborane radical anion. An isostructural uranium(VI)-nitride is inert to hydrogenolysis, suggesting the 5f1 electron of the uranium(V)-nitride is not purely non-bonding. Further FLP reactivity between the uranium(IV)-amide, dihydrogen, and triphenylborane is suggested by the formation of ammonia-triphenylborane. A reactivity cycle for ammonia synthesis is demonstrated, and this work establishes a unique marriage of actinide and FLP chemistries., Despite their importance as mechanistic models for Haber Bosch ammonia synthesis from N2 and H2, high oxidation state terminal metal-nitrides are notoriously unreactive towards H2. Here, the authors report hydrogenolysis of a uranium(V)-nitride, which can occur directly or by Frustrated Lewis Pair chemistry with a borane ancillary.
Published: 2020
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189. Synthesis and Structure of Uranium-Silylene Complexes

Author: Daniel J. Lussier, John Arnold, Michael A. Boreen, I. Joseph Brackbill, Laurent Maron, Iskander Douair, Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Silicon, 010405 organic chemistry, Chemistry, Organic Chemistry, Silylene, chemistry.chemical_element, General Chemistry, Actinide, Uranium, 010402 general chemistry, 01 natural sciences, Bond order, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Crystallography, Covalent bond, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Carbene
Abstract: While carbene complexes of uranium have been known for over a decade, there are no reported examples of complexes between an actinide and a "heavy carbene." Herein, we report the syntheses and structures of the first uranium-heavy tetrylene complexes: (CpSiMe3 )3 U-Si[PhC(NR)2 ]R' (R=tBu, R'=NMe2 1; R=iPr, R'=PhC(NiPr)2 2). Complex 1 features a kinetically robust uranium-silicon bonding interaction, while the uranium-silicon bond in 2 is easily disrupted thermally or by competing ligands in solution. Calculations reveal polarized σ bonds, but depending on the substituents at silicon a substantial π-bonding interaction is also present. The complexes possess relatively high bond orders which suggests primarily covalent bonding between uranium and silicon. These results comprise a new frontier in actinide-heavy main-group bonding.
Published: 2020
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190. Grafting of Lanthanum Complexes on a Functionalized Graphene Surface: Theoretical Investigation on Ethylene and 1,3-Butadiene Homo- and Co-Polymerization

Author: Laurent Maron, Adrien Bathellier, Chiara Dinoi, Iker del Rosal, Diego Moreno, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Allylic rearrangement, Ethylene, Organic Chemistry, 1,3-Butadiene, General Chemistry, Alkylation, Catalysis, chemistry.chemical_compound, chemistry, Polymerization, Polymer chemistry, Copolymer, Lewis acids and bases, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: In this contribution, we describe the use of graphene as an efficient catalyst support and the role it plays in increasing the Lewis acidity of the supported metal complexes. By a density functional theory study, we show that the [La(N(SiMe3 )2 )3 ] complex can be easily grafted on graphene-OH and -COOH functionalized surfaces. Two stable mono-grafted compounds, (gO)-[La(N(SiMe3 )2 )2 ] and (gOO)-[La(N(SiMe3 )2 )2 ], are formed, behaving as stronger Lewis acids than the previously reported silica grafted analogues. To study the role of the graphene support in catalysis, we also computed the catalytic activity of the alkylated (gO)-[La(CH3 )2 ] and (gOO)-[La(CH3 )2 ] complexes in the ethylene and 1,3-butadiene homo- and co-polymerization reactions. Both compounds are efficient catalysts for the homo-polymerization of the ethylene and 1,3-butadiene. For the 1,3-butadiene homo-polymerization, the stereoselectivity outcome of the reaction differs according to the grafting site. The results computed for the co-polymerization reaction, finally, show that the high stability of the allylic products leads to the formation of block copolymers.
Published: 2020
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191. Reactivity of a Molecular Calcium Hydride Cation ([CaH](+)) Supported by an NNNN Macrocycle

Author: Danny Schuhknecht, Thomas P. Spaniol, Jun Okuda, Yan Yang, Laurent Maron, Institute of Inorganic Chemistry [Aachen] (IAC RWTH), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Calcium hydride, 010405 organic chemistry, Cationic polymerization, Hydride ligands, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Nucleophilic substitution, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract: The hydride ligand in the cationic calcium hydride supported by a NNNN-type macrocycle, [(Me4TACD)2Ca2(μ-H)2(THF)][BAr4]2 (1; Me4TACD = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane; THF = te...
Published: 2020
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192. Atom economical coupling of benzophenone and N-heterocyclic aromatics with SmI 2

Author: Grégory Nocton, Nicolas Casaretto, Arnaud Jaoul, Carine Clavaguéra, Laurent Maron, Yan Yang, Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Laboratoire de chimie moléculaire (LCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and École polytechnique (X)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Reaction mechanism, 010405 organic chemistry, Phenanthroline, Metals and Alloys, General Chemistry, Reaction intermediate, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, Bipyridine, chemistry, Computational chemistry, Pyridine, Atom, Materials Chemistry, Ceramics and Composites, Proton NMR, Benzophenone, [CHIM]Chemical Sciences
Abstract: International audience; The use of stoechiometric SmI 2 in combination with benzophenone and N-heterocyclic aromatics such as bipyridine, phenanthroline and neat pyridine allows the direct ortho-coupling of both partners in an atom economical reaction free of any other coupling additives. The transformation was investigated by 1 H NMR, X-ray studies and theoretical calculations providing reaction intermediates and the reaction mechanism.
Published: 2020
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193. Alkali Metal Triphenyl- and Trihydridosilanides Stabilized by a Macrocyclic Polyamine Ligand

Author: Laurent Maron, Valeri Leich, Thomas P. Spaniol, Iskander Douair, Jun Okuda, Danny Schuhknecht, Institute of Inorganic Chemistry [Aachen] (IAC RWTH), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: alkali metals, Hydrogen, Hydrogen Storage, Potassium, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, silanides, Hydrogen storage, chemistry.chemical_compound, metal hydrides, 010405 organic chemistry, Ligand, Communication, Organic Chemistry, General Chemistry, Alkali metal, Communications, 0104 chemical sciences, chemistry, ddc:540, Macrocyclic ligand, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Polyamine, macrocyclic ligands
Abstract: Potassium silanide [KSiH3]∞ contains 4.2 wt % of hydrogen and has been intensely studied as hydrogen storage material. The macrocyclic ligand Me4TACD (1,4,7,10‐tetramethyl‐1,4,7,10‐tetraaminocyclododecane, L) stabilizes the full range of triphenylsilyl complexes [(L)MSiPh3]n (M=Li–Cs), which react with H2 or PhSiH3 to form molecular [(L)MSiH3]n that can be isolated in soluble form and fully characterized., Silanides: The macrocyclic polyamine ligand Me4TACD (L) stabilizes the full range of alkali metal triphenylsilanides [(L)MSiPh3]n (M=Li–Cs) that have been studied in solution and in the solid state. They react with H2 or PhSiH3 to give molecular trihydridosilanides [(L)MSiH3] that are soluble in THF and can be regarded as model complexes for the hydrogen‐storage material [MSiH3]∞.
Published: 2020
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194. Hydrolysis of scandium alkyl derivatives supported by a pentadentate diborate ligand: Interconversion of hydroxo and oxo complexes

Author: Benjamin S. Gelfand, Yan Yang, Warren E. Piers, Jian-Bin Li, Laurent Maron, Daniel W. Beh, Department of Chemistry, University of Calgary, University of Calgary, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Ligand, Dimer, chemistry.chemical_element, Protonation, 010402 general chemistry, 01 natural sciences, Decomposition, 0104 chemical sciences, Inorganic Chemistry, Hydrolysis, chemistry.chemical_compound, chemistry, Polymer chemistry, Materials Chemistry, Reactivity (chemistry), Scandium, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Alkyl
Abstract: Uncontrolled reaction of water with scandium alkyls (compounds 1-R) supported by a dianionic, pentadentate ligand leads to rapid formation of an oxo-bridged dimer (2). Solid state samples can be exposed to ambient atmosphere to generate samples enriched in the bridging dihydroxo dimer 3, which slowly converts to the m-oxo species with elimination of water. DFT computations show that 3 is actually more thermodynamically stable than 2, but the reactivity of 3 with the water eliminated leads to its decomposition to 2 and several hydrolysis products. Some of these products were characterized by X-ray crystallography, specifically a hexameric scandium dihydroxo cluster (4) in which the pentadentate ligand has partially demetallated. Attempts to synthesize hydroxo complex 3 by protonation of 2 also lead to hydrolysis products.
Published: 2020
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195. Stabilization of the Oxidation State plus IV in Siloxide-Supported Terbium Compounds

Author: Ivica Zivkovic, Rosario Scopelliti, Iskander Douair, Chad T. Palumbo, Laurent Maron, Aurélien R. Willauer, Marinella Mazzanti, Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Lanthanide, Coordination sphere, lanthanide, chemistry.chemical_element, Terbium, 010402 general chemistry, chemistry, 01 natural sciences, Catalysis, Electron transfer, Oxidation state, Polymer chemistry, lanthanides, epr, chemistry.chemical_classification, rare earths, complexes, 010405 organic chemistry, terbium, tetravalent terbium, Siloxide, General Chemistry, General Medicine, 3. Good health, 0104 chemical sciences, Cerium, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Counterion, metal-ion-coupled electron transfer, siloxides, cerium(iv)
Abstract: The synthesis of lanthanides other than cerium in the oxidation state +IV has remained a desirable but unmet target until recently, when two examples of Tb-IV with saturated coordination spheres were isolated. Here we report the third example of an isolated molecular complex of terbium(IV), where the supporting siloxide ligands do not saturate the coordination sphere. The fully characterized six-coordinate complex [Tb-IV(OSiPh3)(4)(MeCN)(2)], 2-Tb-Ph, shows high stability and the labile MeCN ligands can be replaced by phosphinoxide ligands. Computational studies suggest that the stability is due to a strong pi(O-Tb) interaction which is stronger than in the previously reported Tb-IV complexes. Cyclic-voltammetry experiments demonstrate that non-binding counterions contribute to the stability of Tb-IV in solution by destabilizing the +III oxidation state, while alkali ions promote Tb-IV/Tb-III electron transfer.
Published: 2020
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196. Molecular Zinc Hydride Cations [ZnH](+): Synthesis, Structure, and CO(2)Hydrosilylation Catalysis

Author: Florian Ritter, Thomas P. Spaniol, Jun Okuda, Iskander Douair, Laurent Maron, Institute of Inorganic Chemistry [Aachen] (IAC RWTH), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Denticity, Methyl formate, Hydrosilylation, Zinc Hydride, Zinc hydride, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, chemistry.chemical_compound, chemoselective catalysis, Formate, Lewis acids and bases, Research Articles, 010405 organic chemistry, hydrosilylation, carbon dioxide, General Chemistry, Silane, Lewis acid, 0104 chemical sciences, chemistry, ddc:540, Protonolysis, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Research Article
Abstract: Protonolysis of [ZnH2]n with the conjugated Brønsted acid of the bidentate diamine TMEDA (N,N,N′,N′‐tetramethylethane‐1,2‐diamine) and TEEDA (N,N,N′,N′‐tetraethylethane‐1,2‐diamine) gave the zinc hydride cation [(L2)ZnH]+, isolable either as the mononuclear THF adduct [(L2)ZnH(thf)]+[BArF 4]− (L2=TMEDA; BArF 4 −=[B(3,5‐(CF3)2‐C6H3)4]−) or as the dimer [{(L2)Zn)}2(μ‐H)2]2+[BArF 4]− 2 (L2=TEEDA). In contrast to [ZnH2]n, the cationic zinc hydrides are thermally stable and soluble in THF. [(L2)ZnH]+ was also shown to form di‐ and trinuclear adducts of the elusive neutral [(L2)ZnH2]. All hydride‐containing cations readily inserted CO2 to give the corresponding formate complexes. [(TMEDA)ZnH]+[BArF 4]− catalyzed the hydrosilylation of CO2 with tertiary hydrosilanes to give stepwise formoxy silane, methyl formate, and methoxy silane. The unexpected formation of methyl formate was shown to result from the zinc‐catalyzed transesterification of methoxy silane with formoxy silane, which was eventually converted into methoxy silane as well., Insoluble, thermally unstable zinc dihydride [ZnH2]n can be converted into robust zinc hydride cations [(L2)ZnH]+ which catalyze the homogeneous hydrosilylation of CO2 to give methoxy silane. Ligand L2 can be as simple as chelating TMEDA.
Published: 2020
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197. Reactivity of Ce(iv) imido compounds with heteroallenes

Author: Carlos Alvarez Lamsfus, Eric J. Schelter, Patrick J. Carroll, Thibault Cheisson, Michael R. Gau, Laurent Maron, Ekaterina Lapsheva, Department of Chemistry, The Pennsylvania State University, Pennsylvania State University (Penn State), Penn State System-Penn State System, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: chemistry.chemical_classification, Trifluoromethyl, Double bond, Metals and Alloys, General Chemistry, Alkali metal, Medicinal chemistry, Catalysis, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, chemistry, Yield (chemistry), Materials Chemistry, Ceramics and Composites, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract: The reactivity of alkali metal capped Ce(iv) imido compounds [M(DME)2][Ce[double bond, length as m-dash]NArF(TriNOx)] (1-M with M = K, Rb, Cs and ArF = 3,5-bis(trifluoromethyl)phenyl) with CO2 and organic isocyanates has been evaluated. 1-Cs reacted with CO2 to yield an organocarbamate complex. Reaction of 1-K and 1-Rb with organic isocyanates yielded organoureate Ce(iv) complexes.
Published: 2020
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198. Incorporation of Boron into Uranium Metallacycles: Synthesis, Structure, and Reactivity of Boron-Containing Uranacycles Derived from Bis(alkynyl)boranes

Author: Iskander Douair, Wangyang Ma, Laurent Maron, Qing Ye, Southern University of Science and Technology (SUSTech), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Reaction mechanism, 010405 organic chemistry, Isocyanide, Organic Chemistry, chemistry.chemical_element, Boranes, General Chemistry, Borane, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Isocyanate, Catalysis, Cycloaddition, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Boron
Abstract: The reaction of uranacyclopropene complex (C5 Me5 )2 U[η2 -1,2-C2 (SiMe3 )2 ] with B-aryl bis(alkynyl)borane PhB(C≡CPh)2 led to the first six-membered uranium metallaboracycle, while the reaction with B-amino bis(alkynyl)borane (Me3 Si)2 NB(C≡CPh)2 afforded an unexpected uranaborabicyclo[2.2.0] complex via [2+2] cycloaddition. The reaction with CuCl revealed the non-innocent property of the rearranged bis(alkynyl)boron species towards oxidant. The reactions with isocyanide DippNC: (Dipp=2,6-iPr2 -C6 H3 ) and isocyanate tBuNCO afforded the novel uranaborabicyclo[3.2.0] complexes. All new complexes have been structurally characterized. DFT calculations were performed to provide more insights into the electronic structures and the reaction mechanism.
Published: 2020
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199. Ethene Activation and Catalytic Hydrogenation by a Low-Valent Uranium Pentalene Complex

Author: F. Geoffrey N. Cloke, Richard A. Layfield, Alexander F. R. Kilpatrick, Laurent Maron, Nikolaos Tsoureas, University of Sussex, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Humboldt University Of Berlin
Subjects: Pentalene, Hydrogen, Atmospheric pressure, Chemistry, Orbital hybridisation, chemistry.chemical_element, General Chemistry, Uranium, Biochemistry, Medicinal chemistry, Bond order, Catalysis, chemistry.chemical_compound, Colloid and Surface Chemistry, Oxidation state, Single bond, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], QD0146
Abstract: The reaction of the uranium(III) complex [U(η8-Pn††)(η5-Cp*)] (1) (Pn†† = C8H4(1,4-SiiPr3)2, Cp* = C5Me5) with ethene at atmospheric pressure produces the ethene-bridged diuranium complex [{(η8-Pn††)(η5-Cp*)U}2(μ-η2:η2-C2H4)] (2). A computational analysis of 2 revealed that coordination of ethene to uranium reduces the carbon–carbon bond order from 2 to a value consistent with a single bond, with a concomitant change in the formal uranium oxidation state from +3 in 1 to +4 in 2. Furthermore, the uranium–ethene bonding in 2 is of the δ type, with the dominant uranium contribution being from f–d hybrid orbitals. Complex 2 reacts with hydrogen to produce ethane and reform 1, leading to the discovery that complex 1 also catalyzes the hydrogenation of ethene under ambient conditions.
Published: 2019
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200. A tetranuclear calcium hydride cluster with a highly symmetric [Ca

Author: Danny, Schuhknecht, Thomas P, Spaniol, Iskander, Douair, Laurent, Maron, and Jun, Okuda
Abstract: A highly symmetric, dicationic tetranuclear calcium hydride cluster with an adamantoid [Ca4H6]2+ core stabilized by the NNN macrocycle Me3TACN (1,4,7-trimethyl-1,4,7-triazacyclononane) was prepared. DFT calculations indicate delocalized bonding within the [Ca4H6]2+ fragment with d-orbital contribution.
Published: 2019

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