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39 results on '"Castro, Ludovic"'

3. Sekiro : La seconde vie des Souls

Author

Castro, Ludovic, Castro, Ludovic, Castro, Ludovic, and Castro, Ludovic

Abstract

Voici une étude complète de Sekiro : sa création, les systèmes de jeu mobilisés, son univers, ses personnages et même sa musique. L'auteur en décrypte les thématiques et n'oublie pas de passer en revue les notions issues de la culture, de l'histoire et des religions japonaises, auxquels le jeu fait appel.Peu de séries de jeux vidéo peuvent se targuer d’avoir autant marqué les années 2010 que celle des Souls. Ce succès épatant et inattendu, le studio FromSoftware le doit principalement au talent du désormais célèbre Hidetaka Miyazaki, dont la vision radicale du jeu vidéo a su rapidement charmer et convaincre. En mai 2014, le réalisateur a été promu président de FromSoftware. Alors qu’il aurait pu continuer à concevoir des Souls ad vitam æternam, il a préféré favoriser le développement de nouvelles franchises. Le premier véritable représentant de cette nouvelle ère est Sekiro : Shadows Die Twice, un jeu d’une richesse inouïe à la cohérence thématique irréprochable. Cet ouvrage revient dans un premier temps sur les coulisses du développement et s’efforce, par le biais d’une comparaison systématique avec la série des Souls, d’examiner l’évolution de la philosophie ludique de FromSoftware. S’ensuivent une analyse détaillée de l’univers, du scénario et des personnages ainsi qu’une étude des influences artistiques, culturelles et historiques des créateurs. La dernière partie décrypte l’oeuvre sous l’angle de sujets transversaux, de ses thématiques à sa bande-son, en passant par la gestion et l’intérêt de la difficulté dans le jeu vidéo.Plongez-vous dès à présent dans la lecture de cette analyse de Sekiro : Shadows Die Twice par un joueur passionné !EXTRAIT"Dans cet ouvrage entièrement consacré à Sekiro, nous vous proposons d’analyser et de décortiquer l’œuvre sous tous ses aspects afin d’en extraire la substantifique moelle. Certaines thématiques de l’histoire du jeu, nous le verrons, résonnent particulièrement bien avec la politique de développement instaurée par Miyazaki

Published
2020

5. Experiments and DFT Computations Combine to Decipher Fe-Catalyzed Amidine Synthesis through Nitrene Transfer and Nitrile Insertion

Author

Coin, Guillaume, primary, Dubourdeaux, Patrick, additional, Avenier, Frédéric, additional, Patra, Ranjan, additional, Castro, Ludovic, additional, Lebrun, Colette, additional, Bayle, Pierre-Alain, additional, Pécaut, Jacques, additional, Blondin, Geneviève, additional, Maldivi, Pascale, additional, and Latour, Jean-Marc, additional

Published
2021
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6. Digital Devil Saga : Genèse et coulisses d'un jeu culte

Author

Castro, Ludovic, Castro, Ludovic, Castro, Ludovic, and Castro, Ludovic

Abstract

Un hommage rendu au jeu vidéo, avec une visée didactique !Le troisième numéro de notre collection Ludothèque est consacré aux diptyques Digital Devil Saga, spin-off de la série Shin Megami Tensei. Le contenu s'intéresse à la création des deux jeux, revient sur son scénario, mêlant mythologie hindoue et cyberpunk, son univers et son gameplay.Le troisième tome d'un recueil unique qui propose de retracer l’histoire du jeu vidéo Digital Devil Saga et de ses influences, à travers des réflexions et des analyses originales.EXTRAITMegami Tensei (MegaTen) est sans conteste l’une des séries les plus anciennes et singulières de l’histoire du J-RPG. Sorti un an après Dragon Quest et la même année que Final Fantasy, Digital Devil Story : Megami Tensei a marqué le début d’une longue histoire pour la société Atlus. Malgré des ventes dérisoires par rapport à celles des deux géants Square et Enix, la Saga est parvenue à acquérir un remarquable succès d’estime et à survivre au passage à la HD grâce à la passion et au travail de ses créateurs. Née d’une volonté de se démarquer et de proposer une alternative aux J-RPG orientés fantasy de l’époque, MegaTen a constamment fait preuve d’un esprit rebelle que les employés du studio ont su ne pas (trop) dénaturer au fil des générations.Parmi ses spin-offs, Shin Megami Tensei : Digital Devil Saga, un diptyque injustement méconnu sorti chez nous sur PS2 en 2006 et 2007. Peu de joueurs s’y étant essayés en sont sortis indemnes, notamment en raison d’un univers et d’une histoire de qualité exceptionnelle qui s’articulent autour d’un background culturel vertigineux de manière cohérente et maîtrisée. Bien que principalement basé sur l’hindouisme, son scénario propose un syncrétisme comme seuls les Japonais savent (bien) le faire en allant également piocher dans le mysticisme quantique et l’anthropologie balzacienne.À PROPOS DE L'AUTEURC’est en explorant le monde de Super Metroid à l’âge de sept ans que Ludovic Castro se retrouve pour la première f

Published
2017

7. A Combined Experimental and Theoretical Study of the Versatile Reactivity of an Oxocerium(IV) Complex: Concerted Versus Reductive Addition

Author

Castro, Ludovic, So, Yat-Ming, Cho, Changwoo, Lortz, Rolf Walter, Wong, Kai-Hong, Wang, Kai, Arnold, Polly L., Au-yeung, Ka Chun, Sung, Herman H. Y., Williams, Ian Duncan, Leung, Wa Hung, Maron, Laurent, Castro, Ludovic, So, Yat-Ming, Cho, Changwoo, Lortz, Rolf Walter, Wong, Kai-Hong, Wang, Kai, Arnold, Polly L., Au-yeung, Ka Chun, Sung, Herman H. Y., Williams, Ian Duncan, Leung, Wa Hung, and Maron, Laurent

Abstract

A combined experimental and theoretical investigation on the cerium(IV) oxo complex [(LOEt)2Ce(=O)(H2O)]⋅MeC(O)NH2 (1; LOEt −=[Co(η5-C5H5){P(O)(OEt)2}3]−) demonstrates that the intermediate spin-state nature of the ground state of the cerium complex is responsible for the versatility of its reactivity towards small molecules such as CO, CO2, SO2, and NO. CASSCF calculations together with magnetic susceptibility measurements indicate that the ground state of the cerium complex is of multiconfigurational character and comprised of 74 % of CeIV and 26 % of CeIII. The latter is found to be responsible for its reductive addition behavior towards CO, SO2, and NO. This is the first report to date on the influence of the multiconfigurational ground state on the reactivity of a metal–oxo complex.

Published
2019

9. A Combined Experimental and Theoretical Study of the Versatile Reactivity of an Oxocerium(IV) Complex: Concerted Versus Reductive Addition

Author

Castro, Ludovic, primary, So, Yat‐Ming, additional, Cho, Chang‐woo, additional, Lortz, Rolf, additional, Wong, Kai‐Hong, additional, Wang, Kai, additional, Arnold, Polly L., additional, Au‐Yeung, Ka‐Chun, additional, Sung, Herman H.‐Y., additional, Williams, Ian D., additional, Leung, Wa‐Hung, additional, and Maron, Laurent, additional

Published
2019
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10. Electronic Structures of Mono-Oxidized Copper and Nickel Phosphasalen Complexes

Author

Xemard, Mathieu, Goudy, Violaine, Braun, Augustin, Tricoire, Maxime, Ricard, Louis, Castro, Ludovic, Louyriac, Elisa, Kefalidis, Christos, Maron, Laurent, Mustieles Marín, Irene, Cheisson, Thibault, Singh-Chauhan, Rohit, Herrero, Christian, Cordier, Marie, Clavaguera, Carine, Nocton, Grégory, Auffrant, Audrey, Laboratoire de chimie moléculaire (LCM), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-École polytechnique (X), Diversity-centric Software Engineering (DiverSe), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-LANGAGE ET GÉNIE LOGICIEL (IRISA-D4), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), 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)-Université de Rennes (UNIV-RENNES)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Rennes (ENS Rennes)-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec, Laboratoire Hétéroéléments et Coordination (DCPH), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Conception d’Architectures Moléculaires et Processus Electroniques (CAMPE), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de physique et chimie des nano-objets (LPCNO), 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 (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des mécanismes réactionnels (DCMR), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.INOR]Chemical Sciences/Inorganic chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

11. Formation of Methane versus Benzene in the Reactions of (C5Me5)(2)Th(CH3)(2) with [CH3PPh3]X (X=Cl, Br, I) Yielding Thorium-Carbene or Thorium-Ylide Complexes

Author

Rungthanaphatsophon, Pokpong, Bathelier, Adrien, Castro, Ludovic, Behrle, Andrew C., Barnes, Charles L., Maron, Laurent, Walensky, Justin R., Department of Chemistry, Missouri University of Science and Technology, University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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
carbenes, [PHYS]Physics [physics], ylides, multiple bonding, [CHIM]Chemical Sciences, organometallics, thorium
Abstract

bibtex: ISI:000412189700021 bibtex\location:'POSTFACH 101161, 69451 WEINHEIM, GERMANY',publisher:'WILEY-V C H VERLAG GMBH',type:'Article',affiliation:'Walensky, JR (Reprint Author), Univ Missouri, Dept Chem, Columbia, MO 65211 USA. Maron, L (Reprint Author), Univ Toulouse, 135 Ave Rangueil, F-31077 Toulouse, France. Maron, L (Reprint Author), LPCNO, CNRS, INSA, UPS,UMR,UMR 5215, 135 Ave Rangueil, F-31077 Toulouse, France. Rungthanaphatsophon, Pokpong; Bathelier, Adrien; Barnes, Charles L.; Walensky, Justin R., Univ Missouri, Dept Chem, Columbia, MO 65211 USA. Bathelier, Adrien; Castro, Ludovic; Maron, Laurent, Univ Toulouse, 135 Ave Rangueil, F-31077 Toulouse, France. Bathelier, Adrien; Castro, Ludovic; Maron, Laurent, LPCNO, CNRS, INSA, UPS,UMR,UMR 5215, 135 Ave Rangueil, F-31077 Toulouse, France.','author-email':'laurent.maron@irsamc.ups-tlse.fr walenskyj@missouri.edu',da:'2018-12-05','doc-delivery-number':'FI7PR',eissn:'1521-3773','funding-acknowledgement':'U.S. Department of Energy, Office of Science, Early Career Research Program [DE-SC-0014174]; Humboldt Foundation; Chinese Academy of Science; CalMip','funding-text':'J.R.W. gratefully acknowledges support for this work from the U.S. Department of Energy, Office of Science, Early Career Research Program under Award Number DE-SC-0014174. L.M. is member of the Instiut Universitaire de France. The Humboldt Foundation, the Chinese Academy of Science and CalMip is acknowledged for either financial support or computing time.','journal-iso':'Angew. Chem.-Int. Edit.','keywords-plus':'CARBON MULTIPLE BOND; MOLECULAR-STRUCTURE; METALLA-ALLENES; URANIUM COMPLEX; TRANS-INFLUENCE; U-IV=C; REACTIVITY; LIGAND; CHEMISTRY; PH2PNSIME3','number-of-cited-references':'42',oa:'Bronze','orcid-numbers':'Walensky, Justin/0000-0003-0221-2675','research-areas':'Chemistry','times-cited':'5','unique-id':'ISI:000412189700021','usage-count-last-180-days':'0','usage-count-since-2013':'9','web-of-science-categories':'Chemistry, Multidisciplinary'\; International audience; The reaction of (C5Me5)(2)Th(CH3)(2) with the phosphonium salts [CH3PPh3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C5Me5)(2)Th[CHPPh3]X, rare terminal phosphorano-stabilized carbenes with thorium. These complexes feature the shortest thorium-carbon bonds (approximate to 2.30 angstrom) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X = Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C5Me5)(2)Th[kappa(2)-(C,C')-(CH2)(CH2)PPh2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH3PPh3]X, X = Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene.

Published
2017
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12. Reductive Disproportionation of CO2 with Bulky Divalent Samarium Complexes

Author

Xemard, Mathieu, Goudy, Violaine, Braun, Augustin, Tricoire, Maxime, Cordier, Marie, Ricard, Louis, Castro, Ludovic, Louyriac, Elisa, Kefalidis, Christos E., Clavaguera, Carine, Maron, Laurent, Nocton, Grégory, 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), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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 National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [CHIM]Chemical Sciences
Abstract

bibtex: ISI:000418109700020 bibtex\location:'1155 16TH ST, NW, WASHINGTON, DC 20036 USA',publisher:'AMER CHEMICAL SOC',type:'Article',affiliation:'Nocton, G (Reprint Author), Univ Paris Saclay, CNRS, Ecole Polytech, LCM, Route Saclay, F-91128 Palaiseau, France. Xemard, Mathieu; Goudy, Violaine; Braun, Augustin; Tricoire, Maxime; Cordier, Marie; Ricard, Louis; Nocton, Gregory, Univ Paris Saclay, CNRS, Ecole Polytech, LCM, Route Saclay, F-91128 Palaiseau, France. Castro, Ludovic; Louyriac, Elisa; Kefalidis, Christos E.; Maron, Laurent, Univ Toulouse, CNRS, UMR 5215, LPCNO,INSA,UPS, Toulouse, France. Clavaguera, Carine, Univ Pari Saclay, Univ Paris Sud, CNRS, Lab Chim Phys, 15 Ave Jean Perrin, F-91405 Orsay, France.','author-email':'greg.nocton@polytechnique.edu',da:'2018-12-05','doc-delivery-number':'FQ1IG',eissn:'1520-6041','funding-acknowledgement':'French National Agency [ANR-15-CE29-0019]; CNRS; Ecole polytechnique; DGA','funding-text':'This project was financed by the French National Agency with grant number ANR-15-CE29-0019. We thank the CNRS and Ecole polytechnique for funding. M.X. is grateful to the DGA for funding. L.M. is a member of the Institut Universitaire de France.','journal-iso':'Organometallics','keywords-plus':'BIPYRIDYL THORIUM METALLOCENE; SOLID-STATE STRUCTURES; RARE-EARTH-ELEMENTS; CARBON-MONOXIDE; ORGANOMETALLIC COMPOUNDS; LANTHANIDE COMPLEXES; CRYSTAL-STRUCTURE; ACTIVATION; REACTIVITY; COORDINATION','number-of-cited-references':'65','orcid-numbers':'Clavaguera, Carine/0000-0001-5531-2333','research-areas':'Chemistry','researcherid-numbers':'Clavaguera, Carine/A-1433-2013 Nocton, Greg/D-4435-2009','times-cited':'3','unique-id':'ISI:000418109700020','usage-count-last-180-days':'7','usage-count-since-2013':'14','web-of-science-categories':'Chemistry, Inorganic & Nuclear; Chemistry, Organic'\; The base-free divalent samarium complex (Cp2Sm)-Sm-tt (1; Cp-tt = 1,3-(Bu-t)(2)(C5H3)) has been synthesized in diethyl ether by salt metathesis of SmI2. Crystals of 1 suitable for X-ray study have been obtained by sublimation at 116 degrees C under reduced pressure. The dissolution of 1 in thf and pyridine solution leads to the solvent adducts (Ce2Sm)-Sm-tt(thf)(2) (3) and (Ce2Sm)-Sm-tt(py) (4), respectively, while drying 3 under reduced pressure yields (CpSm)-Sm-tt(thf) (5). The reaction of CO2 with the base-free divalent samarium complexes (Cp2Sm)-Sm-tt (1) and (Cp2Sm)-Sm-ttt (2; Cp-ttt =1,2,4-(Bu-t)(3)(C5H2)) leads to the clean formation of bridged carbonate samarium dimers [(Cr2Sm)-Sm-ttt](2)(mu-CO3) (7) and [(Cp2Sm)-Sm-tt](2)(mu-CO3) (8). This is indicative of the reductive disproportionation of CO2 in both cases with release of CO. This contrasts with the formation of the oxalate-bridged samarium dimer reported from the reaction of CO2 with the Cp*Sm-2(thf)(2) complex. Otherwise, the reaction with CO does not proceed with the bulky complexes, while traces of O-2 have led to the formation of the original bridged peroxo samarium dimer [Cp(2)(ttt)sm](2)(mu-O-2) (6). The mechanism for these reactions is studied herein by experiments and also by theoretical computations. The key result is that the different pathways are rather close in energy, which also explains why the nature of the final product, if only one is present, is difficult to predict a priori in this chemistry.

Published
2017

15. Concomitant Carboxylate and Oxalate Formation From the Activation of CO 2 by a Thorium(III) Complex

Author

Formanuik, Alasdair, Ortu, Fabrizio, Inman, Christopher, Kerridge, Andrew, Castro, Ludovic, Maron, Laurent, Mills, David, School of Chemistry [Manchester], University of Manchester [Manchester], Department of Chemistry, School of Life Sciences, University of Sussex, Univ Lancaster, Dept Chem, Lancaster LA1 4YB, England, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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), University of Sussex, 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
[CHIM]Chemical Sciences
Abstract

International audience; Improving our comprehension of diverse CO2 activation pathways is of vital importance for the widespread future utilization of this abundant greenhouse gas. CO2 activation by uranium(III) complexes is now relatively well understood, with oxo/carbonate formation predominating as CO2 is readily reduced to CO, but isolated thorium(III) CO2 activation is unprecedented. We show that the thorium(III) complex, [Th(Cp′′)3] (1, Cp′′={C5H3(SiMe3)2‐1,3}), reacts with CO2 to give the mixed oxalate‐carboxylate thorium(IV) complex [{Th(Cp′′)2[κ2‐O2C{C5H3‐3,3′‐(SiMe3)2}]}2(μ‐κ2:κ2‐C2O4)] (3). The concomitant formation of oxalate and carboxylate is unique for CO2 activation, as in previous examples either reduction or insertion is favored to yield a single product. Therefore, thorium(III) CO2 activation can differ from better understood uranium(III) chemistry.

Published
2016

16. Concomitant Carboxylate and Oxalate Formation From the Activation of CO2 by a Thorium(III) Complex

Author

Formanuik, Alasdair, Ortu, Fabrizio, Inman, Christopher J., Kerridge, Andrew, Castro, Ludovic, and Mills, David

Abstract

Improving our comprehension of diverse CO2 activation pathways is of vital importance for the widespread future utilization of an abundant greenhouse gas. CO2 activation by uranium(III) complexes is now relatively well understood, with oxo/carbonate formation predominating as CO2 is readily reduced to CO, but isolated thorium(III) CO2 activation is unprecedented. We show that the thorium(III) complex, [Th(Cp′′)3] (1, Cp′′ = {C5H3(SiMe3)2-1,3}), reacts with CO2 to give the mixed oxalate-carboxylate thorium(IV) complex [{Th(Cp′′)2[κ2-O2C{C5H3-3,3′-(SiMe3)2}]}2(µ-κ2:κ2-C2O4)] (3). The concomitant formation of oxalate and carboxylate is unique for CO2 activation, as in previous examples either reduction or insertion is favored to yield a single product. Therefore, thorium(III) CO2 activation can differ from better understood uranium(III) chemistry.

Published
2016
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17. Activation of Heteroallenes CO x S 2- x ( x = 0-2): Experimental and Theoretical Evidence of the Synthetic Versatility of a Bulky Guanidinato Sm II Complex

Author

Castro, Ludovic, Mills, David, Jones, Cameron, Maron, Laurent, 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 [Manchester], University of Manchester [Manchester], Monash University [Melbourne], School of Chemistry, Monash University, 3800 Clayton, Victoria (Australie), Monash University [Clayton], Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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 School of Chemistry, Monash UniVersity, Clayton, VIC. 3800 (Australia)

Subjects
[CHIM]Chemical Sciences
Abstract

International audience; A joint experimental/theoretical (DFT) study of the activation of heteroallenes COxS2–x (x = 0–2) by [Sm(Giso)2] {Giso– = [(ArN)2CNCy2]–, Cy = cyclohexyl, Ar = 2,6‐diisopropylphenyl} is reported. All heteroallenes are reduced in a different manner. Indeed, while activation of CS2 yields a bimetallic CS2 coupled product through C–S bond formation, CO2 forms an oxalate complex through C–C bond formation. This subsequently undergoes CO2 insertion into one of its Sm–N bonds. Finally, COS activation is predicted to yield a dithiocarbonate complex, through the formation of an intermediate sulfido complex [(Giso)2Sm(µ‐S)Sm(Giso)2]. Therefore, [Sm(Giso)2] is a very versatile reagent, since it is a rare example of a complex that allows formation of several activation products involving valence isoelectronic substrates. This is rationalized by DFT calculations, and the latter emphasizes both the lack of kinetic stability of CS vs. CO and the high thermodynamic stability of the oxalate.

Published
2016

20. Formation of a Bridging Phosphinidene Thorium Complex

Author

Behrle, Andrew, Castro, Ludovic, Maron, Laurent, Walensky, Justin, Department of Chemistry, Missouri University of Science and Technology, 142 Schrenk Hall, 400 West 11th Street, Rolla, Missouri 65409, United States, Missouri University of Science and Technology (Missouri S&T), University of Missouri System-University of Missouri System, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), 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 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
[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; The synthesis and structural determination of the first thorium phosphinidene complex are reported. The reaction of 2 equiv of (C5Me5)2Th(CH3)2 with H2P(2,4,6-iPr3C6H2) at 95 °C produces [(C5Me5)2Th]2(μ2-P[(2,6-CH2CHCH3)2-4-iPrC6H2] as well as 4 equiv of methane, 2 equiv from deprotonation of the phosphine and 2 equiv from C–H bond activation of one methyl group of each of the isopropyl groups at the 2- and 6-positions. Transition state calculations indicate that the steps in the mechanism are P–H, C–H, C–H, and then P–H bond activation to form the phosphinidene.

Published
2015

26. A Theoretical Outlook on the Stereoselectivity Origins of Isoselective Zirconocene Propylene Polymerization Catalysts.

Author

Maron, Laurent, Castro, Ludovic, Therukauff, Gabriel, Carpentier, Jean‐François, Kirillov, Evgueni, Vantomme, Aurelien, Welle, Alexandre, Haspeslagh, Luc, and Brusson, Jean‐Michel

Abstract

Abstract: The first three insertion steps of propylene for isoselective metallocenes from the one‐carbon‐bridged cyclopentadienyl–fluorenyl {Cp/Flu} and silicon‐bridged ansa‐bis(indenyl) {SBI} families were computed by using a theoretical method implementing the B3PW91 functional in combination with solvent corrections incorporated with the Solvation Model based on Density (SMD) continuum model. For C1‐symmetric {Cp/Flu}‐type metallocenes, two mechanisms of stereocontrol were validated theoretically: more facile and more stereoselective chain “stationary” insertion (or site epimerization backskip) and less stereoselective alternating mechanisms. For the C2‐symmetric {SBI}‐type system, the computation results were in complete agreement with the sole operating chain migratory insertion mechanism. The thermochemical data obtained through the study were used to predict microstructures of polypropylenes by using three‐parameter and one‐parameter statistical models for the two metallocene systems, respectively. The calculated meso/rac pentad distributions were found to be in good agreement with those determined experimentally for isotactic polypropylene samples obtained at different polymerization temperatures. [ABSTRACT FROM AUTHOR]

Published
2018
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27. Dinitrogen functionalization at a ditantalum center. Balancing N2 displacement and N2 functionalization in the reaction of coordinated N2 with CS2.

Author

Burford, Richard J., Castro, Ludovic, Maron, Laurent, Hein, Jason E., and Fryzuk, Michael D.

Subjects
*NITROGEN, *CARBON disulfide, *TANTALUM compounds
Abstract

The reaction of carbon disulfide (CS2) with the side-on end-on dinitrogen complex ([NPNSi]Ta)2(μ–η1:η2-N2)(μ-H)2 (1) (where [NPNSi] = [PhP(CH2SiMe2NPh)2]) has been studied and shown to generate two products, the ratio of which depends on the concentration of added carbon disulfide. At high concentrations of CS2, N–N bond cleavage and functionalization occur to generate a ditantalum complex with an isothiocyanato ligand N-bound to Ta along with bridging sulfido and nitrido moieties. At lower concentrations of CS2, less dinitrogen functionalization is observed; instead, N2 is displaced and the CS2 molecule is completely disassembled to generate a ditantalum derivative with bridging methylene and two sulfide moieties. Kinetic and DFT studies have been performed and provide clues about the product ratio and mechanistic information and shed light on why N2 functionalization is challenging. [ABSTRACT FROM AUTHOR]

Published
2018
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28. Dinitrogen functionalization at a ditantalum center. Balancing N2 displacement and N2 functionalization in the reaction of coordinated N2 with CS2.

Author

Burford, Richard J., Castro, Ludovic, Maron, Laurent, Hein, Jason E., and Fryzuk, Michael D.

Subjects
NITROGEN, CARBON disulfide, TANTALUM compounds
Abstract

The reaction of carbon disulfide (CS2) with the side-on end-on dinitrogen complex ([NPNSi]Ta)2(μ–η1:η2-N2)(μ-H)2 (1) (where [NPNSi] = [PhP(CH2SiMe2NPh)2]) has been studied and shown to generate two products, the ratio of which depends on the concentration of added carbon disulfide. At high concentrations of CS2, N–N bond cleavage and functionalization occur to generate a ditantalum complex with an isothiocyanato ligand N-bound to Ta along with bridging sulfido and nitrido moieties. At lower concentrations of CS2, less dinitrogen functionalization is observed; instead, N2 is displaced and the CS2 molecule is completely disassembled to generate a ditantalum derivative with bridging methylene and two sulfide moieties. Kinetic and DFT studies have been performed and provide clues about the product ratio and mechanistic information and shed light on why N2 functionalization is challenging. [ABSTRACT FROM AUTHOR]

Published
2018
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30. Formation of Methane versus Benzene in the Reactions of (C5Me5)2Th(CH3)2 with [CH3PPh3]X (X=Cl, Br, I) Yielding Thorium-Carbene or Thorium-Ylide Complexes.

Author

Rungthanaphatsophon, Pokpong, Bathelier, Adrien, Castro, Ludovic, Behrle, Andrew C., Barnes, Charles L., Maron, Laurent, and Walensky, Justin R.

Subjects
METHANE, BENZENE, CHEMICAL reactions, COMPLEX compounds, CARBENES, PHOSPHONIUM compounds
Abstract

The reaction of (C5Me5)2Th(CH3)2 with the phosphonium salts [CH3PPh3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C5Me5)2Th[CHPPh3]X, rare terminal phosphorano-stabilized carbenes with thorium. These complexes feature the shortest thorium-carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C5Me5)2Th[κ2-(C,C′)-(CH2)(CH2)PPh2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH3PPh3]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene. [ABSTRACT FROM AUTHOR]

Published
2017
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32. Concomitant Carboxylate and Oxalate Formation From the Activation of CO2 by a Thorium(III) Complex.

Author

Formanuik, Alasdair, Ortu, Fabrizio, Inman, Christopher J., Kerridge, Andrew, Castro, Ludovic, Maron, Laurent, and Mills, David P.

Subjects
CHEMICAL synthesis, CARBOXYLATES, OXALATES, CARBON dioxide reduction, ACTIVATION (Chemistry), THORIUM compounds, GREENHOUSE gases, INSERTION reactions (Chemistry), URANIUM compounds synthesis
Abstract

Improving our comprehension of diverse CO2 activation pathways is of vital importance for the widespread future utilization of this abundant greenhouse gas. CO2 activation by uranium(III) complexes is now relatively well understood, with oxo/carbonate formation predominating as CO2 is readily reduced to CO, but isolated thorium(III) CO2 activation is unprecedented. We show that the thorium(III) complex, [Th(Cp′′)3] ( 1, Cp′′={C5H3(SiMe3)2-1,3}), reacts with CO2 to give the mixed oxalate-carboxylate thorium(IV) complex [{Th(Cp′′)2[κ2-O2C{C5H3-3,3′-(SiMe3)2}]}2(μ-κ2:κ2-C2O4)] ( 3). The concomitant formation of oxalate and carboxylate is unique for CO2 activation, as in previous examples either reduction or insertion is favored to yield a single product. Therefore, thorium(III) CO2 activation can differ from better understood uranium(III) chemistry. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
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33. Activation of Heteroallenes CO xS2- x ( x = 0-2): Experimental and Theoretical Evidence of the Synthetic Versatility of a Bulky Guanidinato SmII Complex.

Author

Castro, Ludovic, Mills, David P., Jones, Cameron, and Maron, Laurent

Subjects
*SAMARIUM compounds, *METAL complexes, *CARBON monoxide, *ALLENE, *COVALENT bonds, *THERMAL stability
Abstract

A joint experimental/theoretical (DFT) study of the activation of heteroallenes CO xS2- x ( x = 0-2) by [Sm(Giso)2] {Giso- = [(ArN)2CNCy2]-, Cy = cyclohexyl, Ar = 2,6-diisopropylphenyl} is reported. All heteroallenes are reduced in a different manner. Indeed, while activation of CS2 yields a bimetallic CS2 coupled product through C-S bond formation, CO2 forms an oxalate complex through C-C bond formation. This subsequently undergoes CO2 insertion into one of its Sm-N bonds. Finally, COS activation is predicted to yield a dithiocarbonate complex, through the formation of an intermediate sulfido complex [(Giso)2Sm(µ-S)Sm(Giso)2]. Therefore, [Sm(Giso)2] is a very versatile reagent, since it is a rare example of a complex that allows formation of several activation products involving valence isoelectronic substrates. This is rationalized by DFT calculations, and the latter emphasizes both the lack of kinetic stability of CS vs. CO and the high thermodynamic stability of the oxalate. [ABSTRACT FROM AUTHOR]

Published
2016
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34. Rational design of Fe catalysts for olefin aziridination through DFT-based mechanistic analysisElectronic supplementary information (ESI) available. CCDC 1555831. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7cy01283g

Author

PatraThese authors contributed equally., Ranjan, Coin, Guillaume, Castro, Ludovic, Dubourdeaux, Patrick, Clémancey, Martin, Pécaut, Jacques, Lebrun, Colette, Maldivi, Pascale, and Latour, Jean-Marc

Abstract

Nitrene transfer reactions are increasingly used to access various kinds of amine derivatives but the underlying mechanisms have not been unraveled in most cases. Fe-catalyzed aziridination of alkenes has appeared as a promising route to aziridines which are important derivatives both per seand as intermediates in many synthetic procedures. We report the strong activity and the mechanism of di-iron catalysts for aziridination of styrenes using phenyltosyliodinane (PhINTs). In addition, we have developed a similar mono-iron catalyst which operates under the same mechanism albeit with a reduced activity. DFT calculations were performed to investigate the structure and electronic structure of the FeIVNTs species of the latter catalyst. They suggest that the reaction pathway leading to the nitrene transfer to the olefin involves a transient charge transfer on the way to a radical intermediate, which is totally consistent with the experimental results. Moreover, these calculations identify the electron affinity (EA) of the active species as one key parameter allowing rationalization of the observations, which opens the way to improving the catalyst efficiency on a rational basis.

Published
2017
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35. A Combined Experimental and Theoretical Study of the Versatile Reactivity of an Oxocerium(IV) Complex: Concerted Versus Reductive Addition.

Author

Castro L, So YM, Cho CW, Lortz R, Wong KH, Wang K, Arnold PL, Au-Yeung KC, Sung HH, Williams ID, Leung WH, and Maron L

Abstract

A combined experimental and theoretical investigation on the cerium(IV) oxo complex [(L OEt ) 2 Ce(=O)(H 2 O)]⋅MeC(O)NH 2 (1; L OEt - =[Co(η 5 -C 5 H 5 ){P(O)(OEt) 2 } 3 ] - ) demonstrates that the intermediate spin-state nature of the ground state of the cerium complex is responsible for the versatility of its reactivity towards small molecules such as CO, CO 2 , SO 2 , and NO. CASSCF calculations together with magnetic susceptibility measurements indicate that the ground state of the cerium complex is of multiconfigurational character and comprised of 74 % of Ce IV and 26 % of Ce III . The latter is found to be responsible for its reductive addition behavior towards CO, SO 2 , and NO. This is the first report to date on the influence of the multiconfigurational ground state on the reactivity of a metal-oxo complex., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2019
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36. A Theoretical Outlook on the Stereoselectivity Origins of Isoselective Zirconocene Propylene Polymerization Catalysts.

Author

Castro L, Therukauff G, Vantomme A, Welle A, Haspeslagh L, Brusson JM, Maron L, Carpentier JF, and Kirillov E

Abstract

The first three insertion steps of propylene for isoselective metallocenes from the one-carbon-bridged cyclopentadienyl-fluorenyl {Cp/Flu} and silicon-bridged ansa-bis(indenyl) {SBI} families were computed by using a theoretical method implementing the B3PW91 functional in combination with solvent corrections incorporated with the Solvation Model based on Density (SMD) continuum model. For C 1 -symmetric {Cp/Flu}-type metallocenes, two mechanisms of stereocontrol were validated theoretically: more facile and more stereoselective chain "stationary" insertion (or site epimerization backskip) and less stereoselective alternating mechanisms. For the C 2 -symmetric {SBI}-type system, the computation results were in complete agreement with the sole operating chain migratory insertion mechanism. The thermochemical data obtained through the study were used to predict microstructures of polypropylenes by using three-parameter and one-parameter statistical models for the two metallocene systems, respectively. The calculated meso/rac pentad distributions were found to be in good agreement with those determined experimentally for isotactic polypropylene samples obtained at different polymerization temperatures., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2018
Full Text
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37. Dinitrogen functionalization at a ditantalum center. Balancing N 2 displacement and N 2 functionalization in the reaction of coordinated N 2 with CS 2 .

Author

Burford RJ, Castro L, Maron L, Hein JE, and Fryzuk MD

Abstract

The reaction of carbon disulfide (CS2) with the side-on end-on dinitrogen complex ([NPNSi]Ta)2(μ-η1:η2-N2)(μ-H)2 (1) (where [NPNSi] = [PhP(CH2SiMe2NPh)2]) has been studied and shown to generate two products, the ratio of which depends on the concentration of added carbon disulfide. At high concentrations of CS2, N-N bond cleavage and functionalization occur to generate a ditantalum complex with an isothiocyanato ligand N-bound to Ta along with bridging sulfido and nitrido moieties. At lower concentrations of CS2, less dinitrogen functionalization is observed; instead, N2 is displaced and the CS2 molecule is completely disassembled to generate a ditantalum derivative with bridging methylene and two sulfide moieties. Kinetic and DFT studies have been performed and provide clues about the product ratio and mechanistic information and shed light on why N2 functionalization is challenging.

Published
2018
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38. Formation of Methane versus Benzene in the Reactions of (C 5 Me 5 ) 2 Th(CH 3 ) 2 with [CH 3 PPh 3 ]X (X=Cl, Br, I) Yielding Thorium-Carbene or Thorium-Ylide Complexes.

Author

Rungthanaphatsophon P, Bathelier A, Castro L, Behrle AC, Barnes CL, Maron L, and Walensky JR

Abstract

The reaction of (C 5 Me 5 ) 2 Th(CH 3 ) 2 with the phosphonium salts [CH 3 PPh 3 ]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C 5 Me 5 ) 2 Th[CHPPh 3 ]X, rare terminal phosphorano-stabilized carbenes with thorium. These complexes feature the shortest thorium-carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C 5 Me 5 ) 2 Th[κ 2 -(C,C')-(CH 2 )(CH 2 )PPh 2 ]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH 3 PPh 3 ]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Published
2017
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39. Formation of a Bridging Phosphinidene Thorium Complex.

Author

Behrle AC, Castro L, Maron L, and Walensky JR

Abstract

The synthesis and structural determination of the first thorium phosphinidene complex are reported. The reaction of 2 equiv of (C5Me5)2Th(CH3)2 with H2P(2,4,6-(i)Pr3C6H2) at 95 °C produces [(C5Me5)2Th]2(μ2-P[(2,6-CH2CHCH3)2-4-(i)PrC6H2] as well as 4 equiv of methane, 2 equiv from deprotonation of the phosphine and 2 equiv from C-H bond activation of one methyl group of each of the isopropyl groups at the 2- and 6-positions. Transition state calculations indicate that the steps in the mechanism are P-H, C-H, C-H, and then P-H bond activation to form the phosphinidene.

Published
2015
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