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1. Isolation of a [Fe(CO)4]2–-Bridged Diuranium Complex Obtained via Reduction of Fe(CO)5 with Uranium(III)

Author

Robert J. Ward, Justin R. Walensky, Ambre Carpentier, Karsten Meyer, Steven P. Kelley, Daniel Pividori, Michael L. Tarlton, Laurent Maron, University of Missouri [Columbia] (Mizzou), University of Missouri System, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Energy, Office of Basic Energy Sciences, Heavy Element Program [DE-SC-0021273], Friedrich-Alexander-Universitat Erlangen-Nurnberg (FAU), Bundesministerium fur Bildung und Forschung (f-Char, BMBF) [02NUK059E], Alexander-von-Humboldt Foundation, Chinese Academy of Science, and HPCs CALcul en Midi-Pyrenees (CALMIP-EOS grant) [1415]

Subjects
010405 organic chemistry, Organic Chemistry, chemistry.chemical_element, Uranium, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Inorganic Chemistry, Reduction (complexity), chemistry, Moiety, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract

International audience; Treatment of the U(III) complex, [(C5Me5)(2)U(OMes)(THF)], Mes = 2,4,6-Me3C6H2, with Fe(CO)(5) forms [{(C5Me5)(2)(MesO)U}(2)(mu(2)-(OC)(2)Fe(CO)(2))] with the bridging, tetrahedral Fe(CO)(4) moiety. This complex has been studied using H-1 NMR, IR vibrational, UV-vis electronic absorption, and zero-field Fe-57 Mossbauer spectroscopy as well as single-crystal X-ray diffraction analysis, magnetic measurements, and DFT calculations.

Published
2021
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2. Heterometallic Clusters with Multiple Rare Earth Metal–Transition Metal Bonding

Author

Penglong Wang, Yue Zhao, Kaiying Shi, Iskander Douair, Genfeng Feng, Congqing Zhu, Laurent Maron, 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Nanjing Normal Univ, Key Lab Virtual Geog Environm, Minist Educ, Nanjing 210023, Peoples R China, National Natural Science Foundation of China [21772088, 91961116], Natural Science Foundation of Jiangsu Province [BK20200302], Fundamental Research Funds for the Central Universities [14380216], and Programs for high-level entrepreneurial and innovative talents introduction of Jiangsu Province (group program)

Subjects
Magnetism, Chemistry, Molecular cluster, Rare earth, General Chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Metal, Crystallography, Colloid and Surface Chemistry, Transition metal, X-ray photoelectron spectroscopy, Oxidation state, visual_art, visual_art.visual_art_medium, Molecule, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; Although a series of complexes with rare earth (RE) metal-metal bonds have been reported, complexes which have multiple RE-Rh bonds are unknown. Here we present the identification of the first example of a molecule containing multiple RE-Rh bonds. The complex with multiple Ce-Rh bonds was synthesized by the reduction of a d-f heterometallic molecular cluster Ce{N[((CH2CH2NPPr2)-Pr-i)RhCl(COD)](3)} with excess potassium-graphite. The oxidation state of Ce in 3a appears to be a mixture of Ce(III) and Ce(IV), which was confirmed by X-ray photoelectron spectroscopy, magnetism, and theoretical investigations (DFT and CASSCF). For comparison, the analogous species with multiple La(III)-Rh and Nd(III)-Rh bonds were also constructed. This study provides a possible route for the construction of complexes with multiple RE metal-metal bonds and an investigation of their potential properties and applications.

Published
2021
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3. C–N and C–H Activation of an N-Heterocyclic Carbene by Magnesium(II) Hydride and Magnesium(I) Complexes

Author

Cameron Jones, Laurent Maron, Ambre Carpentier, K. Yuvaraj, Cory D. Smith, 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Australian Research Council

Subjects
Steric effects, 010405 organic chemistry, Hydride, Magnesium, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Adduct, Inorganic Chemistry, IMes, chemistry.chemical_compound, chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Isostructural, Carbene, Mesitylene
Abstract

International audience; Reactions of the hindered N-heterocyclic carbene, :C{(MesNCH)(2)} (IMes; Mes = mesityl), with a series of beta-diketiminatomagnesium(II) hydride and dimagnesium(I) complexes were carried out at 80 degrees C. The reactions involving the magnesium hydrides, [{((Ar)Nacnac)Mg(mu-H)}(2)] [(Ar)Nacnac = [(ArNCMe)(2)CH](-), where Ar = 2,6-diethylphenyl (Dep) or 2,6-diisopropylphenyl (Dip)], proceeded via activation of an exocyclic C-N bond of IMes, giving magnesium imidazolyl compounds [((Ar)Nacnac)Mg(mu-H)(mu-Imid)Mg((Ar)Nacnac)] (Imid = [NC2H2N-(Mes)C](-)) and mesitylene. A low-yield IMes methyl C-H activation product, [((Dep)Nacnac)Mg(IMes(-H))], was also obtained, via H-2 elimination, from the reaction between IMes and [{((Dep)Nacnac)Mg(mu-H)}(2)]. Reactions between IMes and dimagnesium(I) compounds [{((Ar)Nacnac)Mg}(2)] [Ar = 2,6-dimethylphenyl (Xyl) or Mes] afforded isostructural C-H activation products [((Ar)Nacnac)Mg(IMes(-H))] but in higher yields. Density functional theory calculations suggest that the reactions do not progress via stable adduct complex intermediates, which are sterically inaccessible.

Published
2021
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4. Insights into Rare-Earth Metal Complex-Mediated Hydroamination

Author

Kening Qiao, Jian Fang, Laurent Maron, Shuqi Dong, Yan Yang, Bo Liu, Jinjin Chen, Shanghai Institute of Materia Medica - Chinese Academy of Sciences [Shanghai], College of Civil Engineering and Mechanics, Xiangtan Univ., Xiangtan, Hunan 411105, China, Lanzhou Univ, Coll Civil Engn & Mech, Lanzhou, Peoples R China, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Science and Technology of China [Hefei] (USTC), and NSF China [51673184]

Subjects
010405 organic chemistry, Chemistry, Rare earth, Rational design, rare-earth metal complexes, stepwise s-insertive mechanism, DFT calculation, General Chemistry, 010402 general chemistry, 01 natural sciences, Combinatorial chemistry, Catalysis, 0104 chemical sciences, hydroamination, Metal, kinetic study, visual_art, visual_art.visual_art_medium, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Hydroamination, Mechanism (sociology)
Abstract

International audience; Since the precise understanding of the underlying mechanism is important for the rational design of catalysts, much attention has been paid for hydroamination reactions catalyzed by organolanthanides during the past three decades. Distinct mechanisms were proposed on the basis of some key experimental features. It is a challenge to distinguish these mechanisms. The present study focuses on this controversial topic by synthesizing an almost entire range of rare-earth metal bisalkyl complexes (Py-CH2-Flu)Ln(CH2SiMe3)(2)(THF)(x) (Ln = Sc (1), Lu (2), Tm (3), Er (4), Ho (5), Y (6), Dy (7), Tb (8), Gd (9), and Pr (10)) stablized by a pyridine methylene fluorenyl ligand to catalyze intramolecular hydroamination (IAHA) of prototypical 1-amino-2,2-diphenyl-4-pentene and intermolecular hydroamination (IEHA) of styrene and pyrrolidine. Among them, thulium-, terbium-, and gadolinium-based catalysts were investigated for the first time. As observed for all the reported catalytic systems, the rate of IAHA increased almost linearly with increasing metal ion radius, whereas the reactivity pattern in IEHA with respect to the ionic radius size follows the opposite trend. Kinetic studies were carried out to obtain the empirical rate law v = k[Ln](1.0)[S](0.0) for IAHA and v = k[Ln](1.0)[St](1.0)[pyrrolidine](0.0) for IEHA. The zero-order dependence on amine was attributed to the population ratio between the rare-earth metal amido adduct and its precursor being larger than 10(4). Density functional theory studies on scandium, yttrium, and praseodymium complex-mediated IAHA and IEHA were investigated using a stepwise sigma-insertive mechanism and a concerted noninsertive mechanism, respectively. The results suggested the prevailing mechanism to be a stepwise sigma-insertive pathway that involves the insertion of C=C into the Ln-N bond and protonolysis of the Ln-C bond. The protonolysis reaction is the turnover-limiting step. The reason behind the influence of the metal ion radius on the catalytic activity was elucidated.

Published
2021
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5. Computational Insights into Different Mechanisms for Ag‐, Cu‐, and Pd‐Catalyzed Cyclopropanation of Alkenes and Sulfonyl Hydrazones

Author

Laurent Maron, Yong Wu, Iskander Douair, Shanshan Cao, Xihe Bi, Northeast Normal 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), NSFC [21871043, 21961130376], Department of Science and Technology of Jilin Province [20180101185JC, 20190701012GH], and Fundamental Research Funds for the Central Universities [2412020FZ006]

Subjects
Sulfonyl, chemistry.chemical_classification, 010405 organic chemistry, Cyclopropanation, Alkene, Organic Chemistry, General Chemistry, 010402 general chemistry, 01 natural sciences, Combinatorial chemistry, Catalysis, Cycloaddition, 0104 chemical sciences, Cyclopropane, carbenes, reaction mechanisms, chemistry.chemical_compound, chemistry, density functional calculations, hindered alkenes, silver, Diazo, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Carbene
Abstract

International audience; The [2+1] cycloaddition reaction of a metal carbene with an alkene can produce important cyclopropane products for synthetic intermediates, materials, and pharmaceutical applications. However, this reaction is often accompanied by side reactions, such as coupling and self-coupling, so that the yield of the cyclopropanation product of non-silver transition-metal carbenes and hindered alkenes is generally lower than 50 %. To solve this problem, the addition of a low concentration of diazo compound (decomposition of sulfonyl hydrazones) to alkenes catalyzed by either CuOAc or PdCl2 was studied, but side reactions could still not be avoided. Interestingly, however, the yield of cyclopropanation products for such hindered alkenes were as high as 99 % with AgOTf as a catalyst. To explain this unexpected phenomenon, reaction pathways have been computed for four different catalysts by using DFT. By combining the results of these calculations with those obtained experimentally, it can be concluded that the efficiency of the silver catalyst is due to the barrierless concerted cycloaddition step and the kinetic inhibition of side reactions by a high concentration of alkene.

Published
2021
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6. Scandium-Terminal Boronylphosphinidene Complex

Author

Laurent Maron, Xuebing Leng, Yaofeng Chen, Bin Feng, Li Xiang, Ambre Carpentier, University of Chinese Academy of Sciences [Beijing] (UCAS), 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), 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, 21890721, 21821002], K. C. Wong Education Foundation, Strategic Priority Research Program of the Chinese Academy of Sciences [XDB20000000], Shanghai Municipal Committee of Science and Technology, Program of Shanghai Academic Research Leader, and Chinese Academy of Sciences President's International Fellowship Initiative

Subjects
chemistry.chemical_element, General Chemistry, Weak interaction, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 0104 chemical sciences, Bond length, Crystallography, Colloid and Surface Chemistry, chemistry, Nucleophile, Phosphinidene, Reactivity (chemistry), [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Scandium
Abstract

International audience; The first isolation and structural characterization of a rare-earth metal-terminal imido complex were reported in 2010, but a rare-earth metal-terminal phosphinidene complex is still absent, to date. Herein, we report the synthesis and structure of the first example of a rare-earth-terminal phosphinidene complex, namely the scandium boronylphosphinidene complex. Single-crystal X-ray diffraction shows that the complex has a much shorter Sc-P bond length as compared to that in a related scandium boronylphosphido complex, 2.381(1) angstrom vs 2.564(1) angstrom. DFT calculations indicate the presence of a strong Sc-P pi interaction in this complex, which is in striking contrast to the weak interaction found in the phosphido complex. A preliminary reactivity study demonstrates that the scandium-terminal boronylphosphinidene complex behaves as a nucleophilic phosphinidene complex.

Published
2021
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7. Activation of ammonia and hydrazine by electron rich Fe(<scp>ii</scp>) complexes supported by a dianionic pentadentate ligand platform through a common terminal Fe(<scp>iii</scp>) amido intermediate

Author

Warren E. Piers, Michael L. Neidig, Benjamin S. Gelfand, Peter G. N. Neate, Lucie Nurdin, Yan Yang, Laurent Maron, Jian-Bin Lin, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Rochester [USA], Department of Chemical and Petroleum Engineering [Calgary], Natural Sciences and Engineering Research Council of Canada, French CNRS PICS project, Alberta Innovates Technology Futures, Vanier Canada Graduate Scholarships, Chinese Scholarship Council (CSC), and National Institutes of Health [R01GM111480]

Subjects
Hydrogen, 010405 organic chemistry, Ligand, Dimer, Hydrazine, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Redox, 3. Good health, 0104 chemical sciences, Adduct, Chemistry, Ammonia, chemistry.chemical_compound, chemistry, Transition metal, Polymer chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

We report the use of electron rich iron complexes supported by a dianionic diborate pentadentate ligand system, B2Pz4Py, for the coordination and activation of ammonia (NH3) and hydrazine (NH2NH2). For ammonia, coordination to neutral (B2Pz4Py)Fe(ii) or cationic [(B2Pz4Py)Fe(iii)]+ platforms leads to well characterized ammine complexes from which hydrogen atoms or protons can be removed to generate, fleetingly, a proposed (B2Pz4Py)Fe(iii)–NH2 complex (3Ar-NH2). DFT computations suggest a high degree of spin density on the amido ligand, giving it significant aminyl radical character. It rapidly traps the H atom abstracting agent 2,4,6-tri-tert-butylphenoxy radical (ArO˙) to form a C–N bond in a fully characterized product (2Ar), or scavenges hydrogen atoms to return to the ammonia complex (B2Pz4Py)Fe(ii)–NH3 (1Ar-NH3). Interestingly, when (B2Pz4Py)Fe(ii) is reacted with NH2NH2, a hydrazine bridged dimer, (B2Pz4Py)Fe(ii)–NH2NH2–Fe(ii)(B2Pz4Py) ((1Ar)2-NH2NH2), is observed at −78 °C and converts to a fully characterized bridging diazene complex, 4Ar, along with ammonia adduct 1Ar-NH3 as it is allowed to warm to room temperature. Experimental and computational evidence is presented to suggest that (B2Pz4Py)Fe(ii) induces reductive cleavage of the N–N bond in hydrazine to produce the Fe(iii)–NH2 complex 3Ar-NH2, which abstracts H˙ atoms from (1Ar)2-NH2NH2 to generate the observed products. All of these transformations are relevant to proposed steps in the ammonia oxidation reaction, an important process for the use of nitrogen-based fuels enabled by abundant first row transition metals., Synopsis: a highly reactive Fe(iii)–NH2 complex is generated via activation of ammonia or hydrazine in reactions of relevance to fundamental steps in ammonia oxidation processes mediated by an abundant, first row transition metal.

Published
2021
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8. Comparative Insertion Reactivity of CO, CO2, tBuCN, and tBuNC into Thorium– and Uranium–Phosphorus Bonds

Author

Iker del Rosal, Justin R. Walensky, Steven P. Kelley, Sean P. Vilanova, Laurent Maron, and Michael L. Tarlton

Subjects
010405 organic chemistry, Chemistry, Phosphorus, Organic Chemistry, Inorganic chemistry, chemistry.chemical_element, Thorium, Uranium, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Reactivity (chemistry), Physical and Theoretical Chemistry
Abstract

A study of the comparative reactivity of CO, CO2, tBuCN, and tBuNC with (C5Me5)2An[P(H)Mes]2 (An = Th, U) has been undertaken. While CO2 and tBuNC form identical products with both metals, namely (...

Published
2020
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9. Molecular Thorium Trihydrido Clusters Stabilized by Cyclopentadienyl Ligands

Author

Iker del Rosal, Ross O. Piltz, Alison J. Edwards, Jianhua Cheng, Guorui Qin, Laurent Maron, Runhai Chen, Dongmei Cui, and Shihui Li

Subjects
Steric effects, 010405 organic chemistry, Chemistry, Hydride, Neutron diffraction, Thorium, chemistry.chemical_element, General Medicine, Nuclear magnetic resonance spectroscopy, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Metal, Crystallography, Cyclopentadienyl complex, Hydrogenolysis, visual_art, visual_art.visual_art_medium
Abstract

Hydrogenolysis of alkyl-substituted cyclopentadienyl (CpR ) ligated thorium tribenzyl complexes [(CpR )Th(p-CH2 -C6 H4 -Me)3 ] (1-6) afforded the first examples of molecular thorium trihydrido complexes [(CpR )Th(μ-H)3 ]n (CpR =C5 H2 (t Bu)3 or C5 H2 (SiMe3 )3 , n=5; C5 Me4 SiMe3 , n=6; C5 Me5 , n=7; C5 Me4 H, n=8; 7-10 and 12) and [(Cp# )12 Th13 H40 ] (Cp# =C5 H4 SiMe3 ; 13). The nuclearity of the metal hydride clusters depends on the steric profile of the cyclopentadienyl ligands. The hydrogenolysis intermediate, tetra-nuclear octahydrido thorium dibenzylidene complex [(Cpttt )Th(μ-H)2 ]4 (μ-p-CH-C6 H4 -Me)2 (Cpttt =C5 H2 (t Bu)3 ) (11) was also isolated. All of the complexes were characterized by NMR spectroscopy and single-crystal X-ray analysis. Hydride positions in [(CpMe4 )Th(μ-H)3 ]8 (CpMe4 =C5 Me4 H) were further precisely confirmed by single-crystal neutron diffraction. DFT calculations strengthen the experimental assignment of the hydride positions in the complexes 7 to 12.

Published
2020
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10. Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium

Author

Farzaneh Fadaei-Tirani, Laurent Maron, Aurélien R. Willauer, Marinella Mazzanti, Ivica Zivkovic, Chad T. Palumbo, Iskander Douair, 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, lanthanide, Praseodymium, chemistry.chemical_element, Terbium, Ate complex, chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, law.invention, electron-paramagnetic-resonance, Colloid and Surface Chemistry, nitrate, law, Oxidation state, Electron paramagnetic resonance, General Chemistry, 0104 chemical sciences, yttrium, Crystallography, Cerium, ions, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Cyclic voltammetry
Abstract

Out of the 14 lanthanide (Ln) ions, molecular complexes of Ln(IV) were known only for cerium and more recently terbium. Here we demonstrate that the +IV oxidation state is also accessible for the large praseodymium (Pr) cation. The oxidation of the tetrakis(triphenysiloxide) Pr(III) ate complex, [KPr(OSiPh3)(4)(THF)(3)], 1-Pr-Ph, with [N(C6H4Br)(3)][SbCl6], affords the Pr(IV) complex [Pr(OSiPh3)(4)(MeCN)(2)], 2-Pr-Ph, which is stable once isolated. The solid state structure, UV-visible spectroscopy, magnetometry, and cyclic voltammetry data along with the DFT computations of the 2-Pr-Ph complex unambiguously confirm the presence of Pr(IV).

Published
2020
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11. Access to Hydroxy‐Functionalized Polypropylene through Coordination Polymerization

Author

Tiantian Wang, Yuanhao Zhong, Dongmei Cui, Laurent Maron, Iskander Douair, Chunji Wu, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences [Changchun Branch] (CAS), 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
010405 organic chemistry, Allene, technology, industry, and agriculture, macromolecular substances, General Chemistry, 010402 general chemistry, 01 natural sciences, Catalyst poisoning, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Hydroboration, Monomer, chemistry, Polymerization, Polymer chemistry, Copolymer, Coordination polymerization, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Allyl alcohol
Abstract

Preparation of polyethylenes containing hydroxy groups has been already industrialized through radical copolymerization under harsh conditions followed by alcoholysis. By contrast, hydroxy-functionalized polypropylene has proven a rather challenging goal in polymer science. Propylene can't be polymerized through a radical mechanism, and its coordination copolymerization with polar monomers is frustrated by catalyst poisoning. Herein, we report a new strategy to reach this target. The coordination polymerization of allenes by rare-earth-metal precursors affords pure 1,2-regulated polyallenes, which are facilely transformed into poly(allyl alcohol) analogues by subsequent hydroboration/oxidation. Strikingly, the copolymerization of allenes and propylene gives unprecedented hydroxy-functionalized polypropylene after post-polymerization modification. Mechanistic elucidation by DFT simulation suggests kinetic rather than thermodynamic control.

Published
2020
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12. Selective oxo ligand functionalisation and substitution reactivity in an oxo/catecholate-bridged UIV/UIV Pacman complex

Author

Polly L. Arnold, Laurent Maron, Iskander Douair, Jason B. Love, Bradley E. Cowie, University of Edinburgh, 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), Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), and University of California (UC)-University of California (UC)

Subjects
010405 organic chemistry, Chemistry, Ligand, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Small molecule, 0104 chemical sciences, Chalcogen, Molecular geometry, Nucleophile, Oxidation state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Bimetallic strip, Lone pair
Abstract

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
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13. Thorium-nitrogen multiple bonds provide evidence for pushing-from-below for early actinides

Author

Jingzhen Du, Ashley J. Wooles, Stephen T. Liddle, Carlos Alvarez-Lamsfus, Elizabeth P. Wildman, Laurent Maron, School of Chemistry [Manchester], University of Manchester [Manchester], Institut des sciences de l'information et de leurs interactions (INS2I-CNRS), INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Institut National des Sciences Appliquées (INSA), 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), UK Engineering and Physical Sciences Research Council [EP/K024000/1, EP/M027015/1, EP/P001386/1], European Research Council [CoG612724], Royal Society [UF110005], Humboldt Foundation, COST Action [CM1006], CalMip, and University of Manchester

Subjects
Science, General Physics and Astronomy, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, chemistry.chemical_compound, Computational chemistry, lcsh:Science, Multidisciplinary, 010405 organic chemistry, Matrix isolation, Thorium, General Chemistry, Actinide, Triple bond, Uranyl, Multiple bonds, Coordination chemistry, 3. Good health, 0104 chemical sciences, Dication, chemistry, lcsh:Q, Chemical bonding, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

Although the chemistry of uranium-ligand multiple bonding is burgeoning, analogous complexes involving other actinides such as thorium remain rare and there are not yet any terminal thorium nitrides outside of cryogenic matrix isolation conditions. Here, we report evidence that reduction of a thorium-azide produces a transient Th≡N triple bond, but this activates C-H bonds to produce isolable parent imido derivatives or it can be trapped in an N-heterocycle amine. Computational studies on these thorium-nitrogen multiple bonds consistently evidences a σ > π energy ordering. This suggests pushing-from-below for thorium, where 6p-orbitals principally interact with filled f-orbitals raising the σ-bond energy. Previously this was dismissed for thorium, being the preserve of uranium-nitrides or the uranyl dication. Recognising that pushing-from-below perhaps occurs with thorium as well as uranium, and with imido ligands as well as nitrides, suggests this phenomenon may be more widespread than previously thought., Despite the burgeoning nature of uranium–ligand multiple bonding, analogous thorium complexes remain incredibly rare. Here the authors report evidence for a transient thorium–nitride species, which, together with data on parent imido derivatives, suggests that the pushing-from-below phenomenon may be more widespread than previously thought.

Published
2019
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14. Understanding the Multiconfigurational Ground and Excited States in Lanthanide Tetrakis Bipyridine Complexes from Experimental and CASSCF Computational Studies

Author

Laurent Maron, Richard A. Andersen, Grégory Nocton, Corwin H. Booth, J. I. Amaro-Estrada, Robert L. Halbach, Department of Chemistry [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire de chimie moléculaire (LCM), École polytechnique (X)-Institut de Chimie du CNRS (INC)-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), Chemical Sciences Division [LBNL Berkeley] (CSD), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), University of California [Berkeley], University of California-University of California, Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), 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), and 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)

Subjects
Lanthanide, 010405 organic chemistry, Electronic structure, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Magnetic susceptibility, 0104 chemical sciences, Square antiprism, Inorganic Chemistry, Bipyridine, chemistry.chemical_compound, Crystallography, chemistry, Excited state, Molecular orbital, Physical and Theoretical Chemistry, Isostructural
Abstract

International audience; An alternative synthesis for M(κ2-bipy)4 (M = La, Ce) and [Li(thf)4][M(κ2-bipy)4] (M = Tb, Dy) and the crystal structures for M = La, Ce, and Tb are described. The isomorphous and isostructural neutral molecules, M = La and Ce, are polymeric in the solid-state, as are those of M = Sm and Eu, which were reported in earlier work. The polymeric network is built from eight coordinate units whose geometry in all four cases is that of a square prism. The known molecules, M = Yb and Lu, are also polymeric, but the eight coordinate units have dodecahedral geometries. The structure of the anions in the separated ion pair, [Li(thf)4][M(κ2-bipy)4], in which Tb is reported in this work and Lu is known, are monomeric with geometries that are between that of a square antiprism and a dodecahdron. The electronic structure, from CASSCF multireference quantum mechanical calculations, shows that the electronic ground states for M = La and Lu are multiconfigurational spin doublets and those for the M = Ce and Yb are multiconfigurational spin triplets. This is confirmed by magnetic susceptibility studies as a function of temperature that are consistent with the metals (La, Ce, Sm, Tb, Dy, Yb, and Lu) being trivalent, as are the LIII-edge XANES spectra (Ce, Yb), and divalent for Eu. The multiconfigurational nature of the ground states, developed from CASSCF molecular orbital calculations, renders a single Lewis structure and a single reference molecular orbital representation misleading. The results from the multireference calculations are extended to the other lanthanide molecules and are the genesis of a new model for understanding the magnetic properties of these molecules.

Published
2019
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15. Thermally Stable Ln(II) and Ca(II) Bis(benzhydryl) Complexes: Excellent Precatalysts for Intermolecular Hydrophosphination of C–C Multiple Bonds

Author

Alexander A. Trifonov, Elisa Louyriac, Gleb S. Plankin, Andrey S. Shavyrin, Alexander N. Selikhov, Laurent Maron, Anton V. Cherkasov, G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences [Moscow] (RAS), 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), Russian Foundation for Basic Research [17-73-20262], and Russian Science Foundation [17-73-20262] Funding Source: Russian Science Foundation

Subjects
chemistry.chemical_classification, Degree of unsaturation, 010405 organic chemistry, Ligand, Intermolecular force, Thermal decomposition, 010402 general chemistry, 01 natural sciences, Decomposition, 0104 chemical sciences, Inorganic Chemistry, Metal, Crystallography, chemistry, visual_art, visual_art.visual_art_medium, Thermal stability, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Alkyl
Abstract

International audience; A series of Ln(II) and Ca(II) bis(alkyl) complexes with bulky benzhydryl ligands, [(p-tBu-C6H4)(2)-CH](2)M(L-n) (M = Sm, L = DME, n = 2 (1); M = Sm, Yb, Ca, L = TMEDA, n = 1 (2, 3, 4), were synthesized by the salt-metathesis reaction of MI2(THF)(n) (n = 0-2) and [(p-tBu-C6H4)(2)CH]Na--(+). In complex 1, the benzhydryl ligands are bound to the metal center in eta(2)-coordination mode. Unlike complex 1, in isomorphous complexes 3 and 4, due to the coordination unsaturation of the metal center, the both benzhydryl ligands coordinate to the metal in eta(3)-fashion. In complex 2, one ligand is eta(3)-coordinated while the second one is eta(4)-coordinated to the Sm(II) ion. Complexes 2-4 demonstrated unprecedented thermal stability: no evidence of decomposition was observed after heating their solutions in C6D6 at 100 degrees C during 72 h. Complex 1 behaves differently: thermolysis in C6D6 solution at 75 degrees C results in total decomposition in 8 h. Addition of DME promotes decomposition of 2-4 and makes it feasible at 40 degrees C. Complexes 1-4 demonstrated high catalytic activity and excellent regio- and chemoselectivities in intermolecular hydrophosphination of double and triple C-C bonds with both primary and secondary phosphines. Complexes 2 and 3 enable addition of PhPH2 toward the internal C=C bond of Z- and E-stilbenes with 100% conversion under mild conditions. Double sequential hydrophosphination of phenylacetylene with Ph2PH and PhPH2 was realized due to the application of Yb(II) complex as a catalyst.

Published
2019
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16. Scandium and lanthanum hydride complexes stabilized by super-bulky penta-arylcyclopentadienyl ligands

Author

Iker del Rosal, Yang Wang, Xianghui Shi, Laurent Maron, Guorui Qin, Lanxiao Zhao, Jianhua Cheng, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Shanghai Institute of Materia Medica - Chinese Academy of Sciences [Shanghai], National Natural Science Foundation of China [21901238, 21971232], and HPCs CALcul en Midi-Pyrenees (CALMIP-EOS grant ) [1415]

Subjects
010405 organic chemistry, Chemistry, Hydride, Ligand, Metals and Alloys, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Metal, Hydrogenolysis, visual_art, Materials Chemistry, Ceramics and Composites, visual_art.visual_art_medium, Lanthanum, Scandium, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Bimetallic strip
Abstract

International audience; Hydrogenolysis of the half-sandwich penta-arylcycopentadienyl-supported rare-earth metal dibenzyl complexes [(Cp-Ar5)Ln(p-CH2-C6H4-Me)(2)(THF)] (Cp-Ar5 = C5Ar5, Ar = 3,5-Pr-i(2)-C6H3; Ln = Sc, La) afforded a bimetallic scandium complex [(Cp-Ar5)Sc(H)(mu-OC4H9)](2) (2) with two terminal hydrido ligands, and a double-sandwich bimetallic lanthanum hydride complex [(Cp-Ar5)La(mu-H)](2) (4) bearing the reduced Cp-Ar5 ligand. DFT calculations were conducted to elucidate the reaction profiles.

Published
2021
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17. Strongly Polarized Iridium δ− –Aluminum δ+ Pairs: Unconventional Reactivity Patterns Including CO 2 Cooperative Reductive Cleavage

Author

Laurent Veyre, Chloé Thieuleux, Iker del Rosal, Erwann Jeanneau, Laurent Maron, Clément Camp, Léon Escomel, Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265 (C2P2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-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), 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), Université de Lyon, Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-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), 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
Chemistry, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, 3. Good health, 0104 chemical sciences, Crystallography, Colloid and Surface Chemistry, Reductive cleavage, [CHIM]Chemical Sciences, Reactivity (chemistry), [CHIM.COOR]Chemical Sciences/Coordination chemistry, Iridium
Abstract

International audience; The iridium tetrahydride complex Cp*IrH 4 reacts with a range of isobutylaluminum derivatives of general formula Al(iBu) x (OAr) 3−x (x = 1, 2) to give the unusual iridium aluminum species [Cp*IrH 3 Al(i Bu)(OAr)] (1) via a reductive elimination route. The Lewis acidity of the Al atom in complex 1 is confirmed by the coordination of pyridine, leading to the adduct [Cp*IrH 3 Al(i Bu)-(OAr)(Py)] (2). Spectroscopic, crystallographic, and computational data support the description of these heterobimetallic complexes 1 and 2 as featuring strongly polarized Al(III) δ+ −Ir(III) δ− interactions. Reactivity studies demonstrate that the binding of a Lewis base to Al does not quench the reactivity of the Ir−Al motif and that both species 1 and 2 promote the cooperative reductive cleavage of a range of heteroallenes. Specifically, complex 2 promotes the decarbonylation of CO 2 and AdNCO, leading to CO (trapped as Cp*IrH 2 (CO)) and the alkylaluminum oxo ([(iBu)(OAr)Al(Py)] 2 (μ-O) (3)) and ureate ({Al(OAr)(i Bu)[κ 2-(N,O)AdNC(O)-NHAd]} (4)) species, respectively. The bridged amidinate species Cp*IrH 2 (μ-CyNC(H)NCy)Al(i Bu)(OAr) (5) is formed in the reaction of 2 with dicyclohexylcarbodiimine. Mechanistic investigations via DFT support cooperative heterobimetallic bond activation processes.

Published
2021
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18. Cationic Zinc Hydride Catalyzed Carbon Dioxide Reduction to Formate: Deciphering Elementary Reactions, Isolation of Intermediates, and Computational Investigations

Author

R. M. Bhargav, Laurent Maron, Ajay Venugopal, Raju Chambenahalli, Alex P. Andrews, Karl N. McCabe, Florian Ritter, Jun Okuda, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Inorganic Chemistry [Aachen] (IAC RWTH), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), IISER Thiruvananthapuram, and Alexander von Humboldt Foundation

Subjects
carbon dioxide reduction, 010405 organic chemistry, Hydrosilylation, Organic Chemistry, hydrosilylation, chemistry.chemical_element, Zinc hydride, reactive intermediates, General Chemistry, Zinc, Borane, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Hydroboration, chemistry, hydroboration, zinc hydride, Polymer chemistry, Lewis acids and bases, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Electrochemical reduction of carbon dioxide
Abstract

International audience; Zinc has been an element of choice for carbon dioxide reduction in recent years. Zinc compounds have been showcased as catalysts for carbon dioxide hydrosilylation and hydroboration. The extent of carbon dioxide reduction can depend on various factors, including electrophilicity at the zinc center and the denticity of the ancillary ligands. In a few cases, the addition of Lewis acids to zinc hydride catalysts markedly influences carbon dioxide reduction. These factors have been investigated by exploring elementary reactions of carbon dioxide hydrosilylation and hydroboration by using cationic zinc hydrides bearing tetradentate tris[2-(dimethylamino)ethyl]amine and tridentate N,N,N ',N '',N ''-pentamethyldiethylenetriamine in the presence of triphenylborane and tris(pentafluorophenyl)borane.

Published
2021
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19. Calcium-mediated C(sp(3))-H Activation and Alkylation of Alkylpyridines

Author

Laurent Maron, Iker del Rosal, Xin Xu, Xian Xu, Yingming Yao, Xizhou Zheng, 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)-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), 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], PAPD, and HPCs CALcul en Midi-Pyrenees [1415]

Subjects
chemistry.chemical_classification, Calcium hydride, 010405 organic chemistry, Chemistry, Hydride, chemistry.chemical_element, Regioselectivity, Alkylation, Calcium, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Monomer, Pyridine, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Alkyl
Abstract

International audience; Main-group metal calcium-mediated alkylpyridine benzylic C(sp(3))-H activation and functionalization have been achieved. The reaction of a calcium hydride complex [{((DIPP)nacnac)CaH(thf)}(2)] ((DIPP)nacnac = CH{(CMe)(2,6-Pr-i(2)-C6H3N)}(2)) with two equivalents of 2,6-lutidine rapidly yields a monomeric calcium alkyl complex with the release of dihydrogen. A hydride/carbon-bridged binuclear calcium complex [{((DIPP)nacnac)Ca}(2)(mu-H){2-Me-6-(mu-CH2)-Py}(thf)] is obtained from an equimolar treatment of calcium hydride and 2,6-lutidine that is readily converted into mono- or binuclear calcium alkyl complexes upon subsequent addition of 2,6-lutidine. DFT calculations and kinetic studies are conducted to determine their reaction profiles. More significantly, this calcium hydride complex catalyzes regioselective benzylic C-H bond addition of alkylpyridines to a variety of alkenes, affording linear or branched alkylated pyridine derivatives.

Published
2021
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20. Tuning the Regioselective Functionalization of Trifluoromethylated Dienes via Lanthanum‐Mediated Single C−F Bond Activation

Author

Yan Yang, Fabien Massicot, Marc Taillefer, Florian Jaroschik, Yassir Zaid, Dominique Harakat, Elodie Rousset, Laurent Maron, Sirine Sghaier, Jean-Bernard Behr, Tarun Kumar, Agathe Martinez, Xavier Le Goff, Institut de Chimie Moléculaire de Reims - UMR 7312 (ICMR), Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-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), 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 Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
chemistry.chemical_classification, Lanthanide, Diene, 010405 organic chemistry, Chemistry, Alkene, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Regioselectivity, chemistry.chemical_element, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 01 natural sciences, Combinatorial chemistry, Catalysis, 0104 chemical sciences, Metal, chemistry.chemical_compound, visual_art, visual_art.visual_art_medium, Lanthanum, Stereoselectivity, Fulvene
Abstract

International audience; The development of new fluorine-containing building blocks and their efficient synthetic access is currently a challenging research field. Herein, the highly regio- and stereoselective addition of a large range of aldehydes onto trifluoromethylated benzofulvenes was achieved using a simple La/I2/DIBAL-Cl system via a selective C−F bond activation process. This versatile methodology provided homodienyl alcohols bearing a terminal CF2-alkene with potential further applications, as shown by the dehydration to the first benzofulvenes carrying a difluorovinyl group. In addition, for certain electron-poor aldehydes, unprecedented ipso substitution of the CF3 group in a diene was observed, which, according to DFT studies, is related to the presence of the large, Lewis-acidic lanthanum metal.

Published
2021
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21. Dihydrogen cleavage by a dimetalloxycarbene-borane frustrated Lewis pair

Author

Thomas P. Spaniol, Jun Okuda, Christopher C. Cummins, Anh L. P. Nguyen, Laurent Maron, Jared S. Silvia, Albert Paparo, Rhein Westfal TH Aachen, Monash Univ, Dept. mat. Engn, Monash University [Clayton], Massachusetts Institute of Technology (MIT), 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft, Fonds der Chemischen Industrie, and National Science Foundation [CHE-1955612]

Subjects
010405 organic chemistry, chemistry.chemical_element, Borane, 010402 general chemistry, Cleavage (embryo), 01 natural sciences, Medicinal chemistry, Frustrated Lewis pair, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Formate, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Boron
Abstract

Dititanoxycarbene [(TiX3)2(μ-CO2)] (X = N[tBu](3,5-Me2C6H3)) and B(C6F5)3 cleaved dihydrogen under ambient conditions to give the zwitterionic formate [(TiX3)2(μ-OCHO-κO:κO′)(B(C6F5)3)] and the hydrido borate [Ti(N[tBu]Ar)3][HB(C6F5)3].

Published
2021
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22. Catalytic Deoxygenation of Nitroarenes Mediated by High-Valent Molybdenum(VI)-NHC Complexes

Author

Shenyu Liu, Marc Baltrun, Roland Schoch, Stephan Hohloch, Iskander Douair, J. I. Amaro-Estrada, Laurent Maron, University of Paderborn, 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universität Innsbruck [Innsbruck], Daimler and Benz Foundation, Fonds der Chemischen Industrie, Young Academy of the North Rhine-Westphalian Academy of Sciences, Humanities and the Arts, and University of Innsbruck

Subjects
010405 organic chemistry, Organic Chemistry, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Catalysis, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Molybdenum, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Carbene, Deoxygenation
Abstract

International audience; The high-valent molybdenum(VI) N-heterocyclic carbene complexes, (NHC)MoO2 (1) and (NHC)MoO(N+Bu) (2) (NHC = 1,3-bis(3,5-di-tert-butyl-2-phenolato)-benzimidazol-2-ylidene), are investigated toward their catalytic potential in the deoxygenation of nitroarenes. Using pinacol as the sacrificial and green reductant, both complexes are shown to be very active (pre)catalysts for this transformation allowing a reduction of the catalyst loading down to 0.25 mol %. Mechanistic investigations show mu-oxo bridged molybdenum(V) complexes [(NHC)MoO](2)O (4) and [(NHC)Mo((NBu)-Bu-t)](2)O (5) as well as zwitterionic pinacolate benzimidazolium complex 6, with a doubly protonated NHC ligand, to be potentially active species in the catalytic cycle. Both 4 and 5 can be prepared independently by the deoxygenation of 1 and 2 using triethyl phosphine (PEt3) or triphenyl phosphine (PPh3) and were shown to exhibit an unusual multireferenced ground state with a very small singlet-triplet gap at room temperature. Computational studies show that the spin state plays an unneglectable role in the catalytic process, efficiently lowering the reaction barrier of the deoxygenation step. Mechanistic details, putting special emphasis on the fate of the catalyst will be presented and potential routes how nitroarene reduction is facilitated are evaluated.

Published
2021
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23. Al-alkenyl-induced formation of long-chain branched polyethylene via coordinative tandem insertion and chain-transfer polymerization using (nBuCp)2ZrCl2/MAO systems: An experimental and theoretical study

Author

Alexandre Welle, Lorenzo Piola, Olivier Lhost, Karl Mc Cabe, Katty Den Dauw, Aurélien Vantomme, Evgueni Kirillov, Jean-François Carpentier, Laurent Maron, Orlando Santoro, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Total Research and Technology Feluy ( [TRTF]), This work was gratefully supported by Total SA and Total Research and Technology Feluy (postdoctoral and PhD fellowships to OS, LP and KMC)., Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Institut de 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), and 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)

Subjects
Polymers and Plastics, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, Branching (polymer chemistry), 01 natural sciences, Catalysis, chemistry.chemical_compound, Al-alkenyl, Polymer chemistry, Long-Chain Branching, Materials Chemistry, Copolymer, Moiety, [CHIM]Chemical Sciences, Ethylene Polymerization, Metallocene, DFT Calculations, Rheology, Chemistry, Organic Chemistry, Chain transfer, Polyethylene, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, Polymerization, 0210 nano-technology
Abstract

International audience; Recently, we have identified the Al-alkenyl species iBuAl(oct-7-en-1-yl)2 (Al-1) as a promising long-chain branching (LCB) promoter in the ethylene polymerization catalyzed by rac-{EBTHI}ZrCl2-based systems, proposing the incorporation of its alkenyl moiety into the growing polyethylene (PE) chain as a crucial step for LCB formation. The success of the process was attributed to the high copolymerization ability of the selected catalyst. In the present contribution, we aimed at probing the efficiency of Al-1 in combination with catalyst systems based on the unbridged metallocene (nBuCp)2ZrCl2 (Zr-1), namely homogeneous Zr-1/MAO or heterogeneous MAO on silica-supported-Zr-1/TIBAL (supp-Zr-1/TIBAL); in the literature, such systems are claimed to be less efficient copolymerization catalysts compared to bridged systems (i.e. rac-{EBTHI}ZrCl2). In fact, while the supported catalyst produces only purely linear PEs, branched structures were obtained in the presence of the congener homogenous system. Remarkably, the qualitative rheological data suggest that the extent of LCB formation in such samples is comparable to that of the PEs synthesized under similar reaction conditions with the EBTHI/MAO/Al-1 system. This testifies that the Al-alkenyl species is a suitable LCB promoter, even with metallocenes having quite different copolymerization ability (at least in that series). This was rationalized considering the formation of a Zr/Al heterobimetallic species facilitating the Al-1 incorporation via the coordinative tandem insertion and chain-transfer polymerization mechanism, identified in the previous study, and supported by new DFT computations.

Published
2021
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24. Reduced Arene Complexes of Hafnium Supported by a Triamidoamine Ligand

Author

Priyabrata Ghana, Thomas P. Spaniol, Jun Okuda, Laurent Maron, Ulli Englert, Rajeshkhumar Thayalan, Sebastian Schrader, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Deutsche Forschungsgemeinschaft

Subjects
Nitrile, hafnium, DFT calculation, Protonation, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, insertion, chemistry.chemical_compound, Deprotonation, Oxidation state, oxidation state, Research Articles, Coordination Chemistry | Hot Paper, Anthracene, 010405 organic chemistry, Ligand, General Chemistry, 0104 chemical sciences, Benzonitrile, chemistry, Azobenzene, ddc:540, arene ligand, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Research Article
Abstract

A series of hafnium complexes with a reduced arene of the general formula [K(L)][Hf(Xy‐N3N)(arene)] (Xy‐N3N={(3,5‐Me2C6H3)NCH2CH2}3N3−, L=THF, 18‐crown‐6; arene=C10H8 2−, C14H10 2−) mimic the chemistry of hafnium in its formal oxidation state +II. All compounds were obtained upon reduction of the chlorido complex [HfCl(Xy‐N3N)(thf)] with two equivalents of potassium naphthalenide or anthracenide. The reducing nature and the basicity of the reduced anthracene ligand were explored in the reaction of benzonitrile and azobenzene, and by deprotonation of tert‐butylacetylene, respectively. The reduction of benzonitrile provides an initial double nitrile insertion product under kinetic control that rearranges after extrusion of one of the inserted nitriles to a hafnium imido complex as the thermodynamic product. The reduction of azobenzene resulted in a diphenylhydrazido(2−) complex. Treatment of terminal alkynes with the anthracene or diphenylhydrazido(2−) complex led to the selective protonation of the corresponding dianionic ligand., A reduced anthracene complex of hafnium(IV) reacts with two equivalents of benzonitrile to form the hafnium‐bis(iminyl) as the kinetic product that expulses one equivalent of benzonitrile to give an imido complex.

Published
2021
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25. Hydroarylation of olefins catalysed by a dimeric ytterbium(II) alkyl

Author

Laurent Maron, Iskander Douair, Mathew D. Anker, Georgia M. Richardson, Robert A. Keyzers, Joe Bracegirdle, Michael S. Hill, Scott A. Cameron, Victoria University of Wellington, 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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Bath [Bath], AINSE Early Career Research Grant, AINSE Honours Scholarship, Curtis-Gordon Research Scholarship, Dr. Margaret L. Bailey Award, and Victoria University of Wellington Doctoral Scholarship

Subjects
Catalyst synthesis, Science, General Physics and Astronomy, Alkylation, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, General Biochemistry, Genetics and Molecular Biology, Article, Catalysis, Propene, chemistry.chemical_compound, Nucleophile, Reactivity (chemistry), Benzene, Multidisciplinary, 010405 organic chemistry, Hydride, [CHIM.ORGA]Chemical Sciences/Organic chemistry, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, Homogeneous catalysis, 0104 chemical sciences, chemistry, SN2 reaction, lipids (amino acids, peptides, and proteins)
Abstract

Although the nucleophilic alkylation of aromatics has recently been achieved with a variety of potent main group reagents, all of this reactivity is limited to a stoichiometric regime. We now report that the ytterbium(II) hydride, [BDIDippYbH]2 (BDIDipp = CH[C(CH3)NDipp]2, Dipp = 2,6-diisopropylphenyl), reacts with ethene and propene to provide the ytterbium(II) n-alkyls, [BDIDippYbR]2 (R = Et or Pr), both of which alkylate benzene at room temperature. Density functional theory (DFT) calculations indicate that this latter process operates through the nucleophilic (SN2) displacement of hydride, while the resultant regeneration of [BDIDippYbH]2 facilitates further reaction with ethene or propene and enables the direct catalytic (anti-Markovnikov) hydroarylation of both alkenes with a benzene C-H bond., Nucleophilic alkylation of aromatics with main group reagents was achieved, but it is limited to a stoichiometric regime. Here, the authors report that the ytterbium(II) hydride reacts with ethene and propene to afford ytterbium(II) n-alkyls, both of which can facilitate the catalytic alkylation of benzene at room temperature via an SN2 mechanism.

Published
2021
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26. A monoanionic pentadentate ligand platform for scandium-pnictogen multiple bonds

Author

Warren E. Piers, Laurent Maron, Yan Yang, Evan A. Patrick, Benjamin S. Gelfand, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Chemical and Petroleum Engineering [Calgary], Department of Chemistry, University of Calgary, NSERC of Canada, Canada Research Chair, Alberta Innovates, and HPCs CALcul en Midi-Pyrenees (CALMIP-EOS grant) [1415]

Subjects
010405 organic chemistry, Chemistry, Ligand, Metals and Alloys, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Multiple bonds, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, 3. Good health, Crystallography, Phosphinidene, Yield (chemistry), Materials Chemistry, Ceramics and Composites, Scandium, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Pnictogen, Bond cleavage
Abstract

International audience; A new monoanionic pentadentate ligand is designed to accommodate Sc = E bonds (E = N, P). The imido complex is stable enough to isolate and characterize, and reacts rapidly with CO2. The phosphinidene, on the other hand, is highly reactive and induces C-C bond cleavage to yield a phosphido-pyridyl complex which also undergoes rapid reacton with CO2.

Published
2021
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27. Zinc hydride cation [ZnH](+) supported by TMPDA (TMPDA = N,N,N ',N '-tetramethylpropane-1,3-diamine)

Author

Laurent Maron, Karl N. McCabe, Thomas P. Spaniol, Jun Okuda, Florian Ritter, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Deutsche Forschungsgemeinschaft through the International Research Training Group 'Selectivity in Chemo-and Biocatalysis

Subjects
Dimer, ved/biology.organism_classification_rank.species, chemistry.chemical_element, Zinc hydride, Zinc, Conjugated system, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Inorganic Chemistry, chemistry.chemical_compound, Diamine, Materials Chemistry, Chelation, Physical and Theoretical Chemistry, 3c, Hydride, 010405 organic chemistry, ved/biology, N-donor ligand, 0104 chemical sciences, Chelate, chemistry, 2e bond, Protonolysis, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Conjugate acid
Abstract

International audience; Selective protonolysis of polymeric zinc dihydride [ZnH2](n) by the conjugate acid of the chelating N,N-donor TMPDA (TMPDA = N,N,N',N'-tetramethylpropane-1,3-diamine) [(TMPDA)H)][B(3,5-(CF3)(2)-C6H3)(4)] in THF gave the molecular zinc hydride cation [(TMPDA)ZnH(thf)][B(3,5-(CF3)(2)-C6H3)(4)] that is stable in THF but crystallized as the dimer [(TMPDA)(2)Zn-2(mu-H)(2)][B(3,5-(CF3)(2)-C6H3)(4)](2) from CH2Cl2/n-pentane. The protonolysis with half equivalent of the conjugate acid or the reaction of isolated [(TMPDA)ZnH (thf)][B(3,5-(CF3)(2)-C6H3)(4)] with one equivalent of zinc dihydride in THF gave the molecular dizinc trihydride cation [(TMPDA)(2)Zn2H2(mu-H)][B(3,5-(CF3)(2)-C6H3)(4)]. (C) 2021 Elsevier Ltd. All rights reserved.

Published
2021
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28. Calcium Hydride Catalysts for Olefin Hydrofunctionalization: Ring-Size Effect of Macrocyclic Ligands on Activity

Author

Danny Schuhknecht, Thomas Höllerhage, Laurent Maron, Alisha Mistry, Thomas P. Spaniol, Jun Okuda, Yan Yang, 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)-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), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft, Chinese Scholarship Council (CSC), and Projekt DEAL

Subjects
calcium hydride, Hydrosilylation, Dimer, chemistry.chemical_element, Calcium, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Catalysis, chemistry.chemical_compound, Pentagonal bipyramidal molecular geometry, Hydrogenolysis, Calcium hydride, 010405 organic chemistry, Hydride, Communication, Organic Chemistry, hydrosilylation, General Chemistry, Communications, 0104 chemical sciences, macrocycles, chemistry, ddc:540, kinetic analysis, Protonolysis, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], hydrogenation
Abstract

The fifteen‐membered NNNNN macrocycle Me5PACP (Me5PACP=1,4,7,10,13‐pentamethyl‐1,4,7,10,13‐pentaazacyclopentadecane) stabilized the [CaH]+ fragment as a dimer with a distorted pentagonal bipyramidal coordination geometry at calcium. The hydride complex was prepared by protonolysis of calcium dibenzyl with the conjugate acid of Me5PACP followed by hydrogenolysis or treating with nOctSiH3 of the intermediate calcium benzyl cation. The calcium hydride catalyzed the hydrogenation and hydrosilylation of unactivated olefins faster than the analogous calcium complex stabilized by the twelve‐membered NNNN macrocycle Me4TACD (Me4TACD=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane). Kinetic investigations indicate that higher catalytic efficiency for the Me5PACP stabilized calcium hydride is due to easier dissociation of the dimer in solution when compared to the Me4TACD analogue., Macrocyclic ligands recognize ion size, but are rarely used to influence metal‐centered catalytic activity. Calcium hydride cation [CaH]+ supported by the fifteen‐membered NNNNN macrocycle Me5PACP (Me5PACP=1,4,7,10,13‐pentamethyl‐1,4,7,10,13‐pentaazacyclopentadecane) catalyzes hydrogenation and hydrosilylation of unactivated olefins significantly faster than the analogous calcium catalyst containing the twelve‐membered NNNN macrocycle (see figure).

Published
2021
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29. Long-Chain Branched Polyethylene via Coordinative Tandem Insertion and Chain-Transfer Polymerization Using rac-{EBTHI}ZrCl2/MAO/Al-alkenyl Combinations: An Experimental and Theoretical Study

Author

Alexandre Welle, Karl Mc Cabe, Jean-François Carpentier, Katty Den Dauw, Orlando Santoro, Lorenzo Piola, Olivier Lhost, Aurélien Vantomme, Evgueni Kirillov, Laurent Maron, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), 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), Total Research and Technology Feluy ( [TRTF]), Total SA and Total Research and Technology Feluy, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut 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, Polymers and Plastics, 02 engineering and technology, Aluminum metallography, 010402 general chemistry, Branching (polymer chemistry), 01 natural sciences, Polymerization, Inorganic Chemistry, Isomers, chemistry.chemical_compound, Transmetalation, 13C NMR spectroscopy, Transfer agent, Branched polyethylenes, Polymer chemistry, Materials Chemistry, thermal control, [CHIM]Chemical Sciences, Tailored properties, Nuclear magnetic resonance spectroscopy, building control, Chemistry, Organic Chemistry, Cationic polymerization, Aliphatic compounds, Chain transfer, Silica, Aluminum compounds, Mechanistic pathways, 021001 nanoscience & nanotechnology, neural networks, 0104 chemical sciences, Chain transfer polymerization, Kinetic competitions, Supervisory control, Hetero bimetallic complexes, Rheological studies, Density functional theory, Polyethylenes, 0210 nano-technology
Abstract

International audience; In situ synthesis of topologically modified linear polyethylenes (PE) using single-site polymerization catalysis is a challenging task, but it can enable the production of valuable advanced polymer materials with tailored properties. Described herein is an investigation aimed at the efficient generation of long-chain branches (LCB) in linear PEs using Al-alkenyl species, namely, iBuAl(oct-7-en-1-yl)2 (Al-1), in combination with homogeneous rac-{EBTHI}ZrCl2 (Zr-1)/MAO or heterogeneous MAO on silica-supported-rac-{EBTHI}ZrCl2 (supp-Zr-1)/TIBAL catalytic systems. As corroborated by extensive rheological studies and 13C NMR spectroscopy, the Al-alkenyl reagent was found to be quite efficient in the formation of LCB, via a mechanistic pathway involving both insertion and transmetallation reactions. Formation of LCB has been rationalized by density functional theory (DFT) computations carried out on the putative [rac-{EBTHI}Zr-R]+ (R = Me, nPr, and pentyl) cationic species and including a solvent model. Of the three possible isomers of Al/Zr heterobimetallic complexes derived from the cationic species [rac-{EBTHI}Zr-R]+ and Al-1, only one was identified, on kinetic and thermodynamic grounds, as the key intermediate. The DFT study also unveiled that (i) insertion of ethylene into the Zr-alkyl bond of the growing PE chain is accompanied by a reversible decoordination of the Al-vinyl transfer agent (AVTA), (ii) the vinyl 1,2-coordination/insertion of the alkenyl moieties of Al-1 into the Zr-alkyl bond, resulting in the formation of branching, is in direct kinetic competition with the insertion of ethylene, and (iii) the recoordination of the AVTA after either insertion step is thermodynamically favored and mostly responsible for the transmetallation phenomenon.

Published
2020
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30. Interactions in saccharide/cation/water systems: Insights from density functional theory

Author

H. Roux-de Balmann, Sylvain Galier, Laurent Maron, Johanne Teychené, Toulouse Biotechnology Institute (TBI), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire de physique et chimie des nano-objets (LPCNO), 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 de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement - INRAE (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, 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), and 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)

Subjects
Sucrose, Coordination number, Enthalpy, Carbohydrates, Biotechnologie, Hydration, Sequence (biology), Xylose, 01 natural sciences, DFT, Analytical Chemistry, chemistry.chemical_compound, 0404 agricultural biotechnology, Saccharide, [CHIM.GENI]Chemical Sciences/Chemical engineering, Computational chemistry, Cations, medicine, Molecule, Génie chimique, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Dehydration, [INFO.INFO-BT]Computer Science [cs]/Biotechnology, Génie des procédés, Density Functional Theory, Ions, Aqueous solution, 010401 analytical chemistry, Water, 04 agricultural and veterinary sciences, General Medicine, medicine.disease, 040401 food science, 6. Clean water, 0104 chemical sciences, Glucose, chemistry, Metals, Thermodynamics, Density functional theory, Hydrophobic and Hydrophilic Interactions, Food Science
Abstract

International audience; Interactions between saccharides and ions in aqueous solutions are of great importance in many fields (chemistry, physico-chemistry, biology, food industries). Thus, this work proposes to develop a methodology dealing with the characterization and the understanding of interactions between saccharides and cations in presence of water molecules, by a quantum mechanics approach. In the first part, the saccharide hydration properties (xylose, glucose, sucrose) in pure water are determined. Results show that the saccharide coordination numbers, as well as the saccharides hydration enthalpy, increase with the saccharide hydrophilic group number. In the second part, the influence of cations on saccharides hydration properties, and inversely, is evaluated. In saccharide/cation/water systems, the decrease in hydration enthalpy of cations and saccharides shows that both species are dehydrated and that saccharide dehydration depends on the nature of the cation. The dehydration sequence of saccharides was explained from the study of saccharide/cation interactions.

Published
2020
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31. Delivery of a Masked Uranium(II) by an Oxide-Bridged Diuranium(III) Complex

Author

Laurent Maron, Iskander Douair, Marinella Mazzanti, Farzaneh Fadaei-Tirani, Chad T. Palumbo, Dieuwertje K. Modder, 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)-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
lanthanide(iii)/actinide(iii) differentiation, coordination, Molecular model, Oxide, reduction, 010402 general chemistry, c bond formation, ligand, chemistry, 01 natural sciences, Catalysis, Metal, uranium, chemistry.chemical_compound, Bipyridine, Oxidation state, Pyridine, Polymer chemistry, Reactivity (chemistry), magnetic blocking, 010405 organic chemistry, small-molecule activation, General Chemistry, General Medicine, 0104 chemical sciences, reactivity, bipyridine, n-heterocycles, visual_art, visual_art.visual_art_medium, polymetallic complexes, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], tris(cyclopentadienyl) complexes, Linker
Abstract

Oxide is an attractive linker for building polymetallic complexes that provide molecular models for metal oxide activity, but studies of these systems are limited to metals in high oxidation states. Herein, we synthesized and characterized the molecular and electronic structure of diuranium bridged U-III/U-IV and U-III/U-III complexes. Reactivity studies of these complexes revealed that the U-O bond is easily broken upon addition of N-heterocycles resulting in the delivery of a formal equivalent of U-III and U-II, respectively, along with the uranium(IV) terminal-oxo coproduct. In particular, the U-III/U-III oxide complex effects the reductive coupling of pyridine and two-electron reduction of 4,4 '-bipyridine affording unique examples of diuranium(III) complexes bridged by N-heterocyclic redox-active ligands. These results provide insight into the chemistry of low oxidation state metal oxides and demonstrate the use of oxo-bridged U-III/U-III complexes as a strategy to explore U-II reactivity.

Published
2020
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32. Stepwise Construction of Silica-supported Tantalum/Iridium Heteropolymetallic Catalysts Using Surface Organometallic Chemistry

Author

Laurent Veyre, Laurent Maron, Sébastien Lassalle, Iker del Rosal, Ribal Jabbour, Clément Camp, Anne Lesage, Chloé Thieuleux, Emiliano Fonda, David Gajan, Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265 (C2P2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de RMN à très hauts champs de Lyon (CRMN), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)

Subjects
Surface (mathematics), Molecular model, tantalum, Tantalum, chemistry.chemical_element, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Surface OrganoMetallic Chemistry (SOMC), [CHIM]Chemical Sciences, hydrogen isotope exchange (HIE), [CHIM.COOR]Chemical Sciences/Coordination chemistry, Iridium, Physical and Theoretical Chemistry, Organometallic chemistry, X-ray absorption spectroscopy, alkane metathesis, 010405 organic chemistry, early/late heterobimetallic species, Alkane metathesis, hydrides, [CHIM.CATA]Chemical Sciences/Catalysis, iridium, 0104 chemical sciences, Crystallography, chemistry, supported Dual-Atom Catalysts (DACs)
Abstract

International audience; A stepwise surface organometallic chemistry (SOMC) methodology consisting in using a silica-supported tantalum species, [(≡SiO)Ta(CH t Bu)(CH2 t Bu)2], as a reactive center to coordinate an iridium site, was developed to construct tantalum/iridium heterobimetallic edifices. The resulting material, MAT-2, exhibits enhanced catalytic performances-both in H/D isotopic exchange and alkane metathesis reactions-in comparison to MAT-1, which was prepared from the direct grafting on silica of a well-defined heterobimetallic Ta/Ir complex. We projected that the difference in catalytic activity was due to the presence of distinct active sites and we used a combination of advanced spectroscopic methods (IR, solid-state NMR and XAS spectroscopies) as well as modeling (computational studies and molecular models) to identify the structure of these surface species. These investigations point towards the presence of three types of active sites at the surface of MAT-2: the heterobimetallic surface species, [≡SiOTa(CH2 t Bu)2{IrH2(Cp*)}] 2-s, which is also found in MAT-1, as well as an unanticipated heterotrimetallic species, [≡SiOTa(CH2 t Bu)2{IrH2(Cp*)}], 3-s along with some unreacted monometallic Ta sites [(≡SiO)Ta(CH t Bu)(CH2 t Bu)2], 1-s. The well-defined trimetallic surface species 3-s was independently prepared and characterized to support this hypothesis. This study highlights the importance of the synthetic methodology used for the preparation of heterobimetallic species through SOMC, and the difficulty to obtain true single-sites surface species.

Published
2020
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33. 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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34. 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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35. 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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36. 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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37. 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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38. 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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39. 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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40. 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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41. 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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42. 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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43. 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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44. 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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45. 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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46. 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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47. 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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48. 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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49. 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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50. 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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