sophiecarenco

Well defined 25 nm nickel phosphide nanoparticles act as a colloidal catalyst for the chemoselective hydrogenation of terminal and internal alkynes. Cis-alkenes are obtained in mild conditions with good conversion and selectivity. The phosphorus inserted in the Ni–P nanoparticles is critical for the selectivity of the nanocatalyst. Mechanistic investigations using isotope labeling provide insight on the reactants interaction with the nanoparticles surface. They pinpoint the occurrence of C-H bond cleavage in terminal alkynes during the reaction.

S. Carenco, A. Leyva-Pérez, P. Concepción, C. Boissière, N. Mézailles, C. Sanchez, A. Corma, Nano Today 2012, 7, 21.

The interplay between crystallization and phosphorus diffusion in the versatile synthesis of metal phosphide nanoparticles from well-defined metal nanoparticles is studied by using a favorable “P(0)” source for mechanistic studies: white phosphorus. In this study, the reaction of Ni, Fe, Pd, and Cu nanoparticles with P₄ was quantitative even at relatively low temperatures thanks to the high reactivity of this soluble “P” source. Intermediate amorphous alloys could be identified for the first time in the case of Fe and Pd, while the quantitative character of the reaction provided a selective and controlled access to Pd₅P_{4 versus PdP2 and Cu3P versus CuP2.}

S. Carenco, Y. Hu, I. Florea, O. Ersen, C. Boissière, N. Mézailles, C. Sanchez, Chem. Mater. 2012, 24, 4134.

A comparative study of the coordination modes of a (thiophosphinoyl)(trimethylsilyl)methanide and bis(thiophosphinoyl)methanide ligand with RhI was carried out. Several complexes were synthesized and characterized. In one case, a dynamic equilibrium between these two modes of coordination was observed. DFT calculations were carried out to rationalize this phenomenon and the stability of the methanide compounds.

H. Heuclin, S. Carenco, X.-F. Le Goff, N. Mézailles, Eur. J. Inorg. Chem. 2012, 2012, 2320.

The widely used preparation of Ni(0) nanoparticles from [Ni(acac)₂] and oleylamine, often considered to be a thermolysis or a radical reaction, was analyzed anew by using a combination of DFT modeling and designed mechanistic experiments. The oleylamine was shown to reduce the [Ni(acac)₂] complex not through a one-electron radical mechanism, as often stated, but as an hydride donor through a two-electron chemical reduction route. This finding has strong consequences not only for the design of further nanoparticles syntheses that use long-chain amine as a reactant, but also for advanced understanding of catalytic reactions for which these nanoparticles can be employed.

S. Carenco, S. Labouille, S. Bouchonnet, C. Boissière, X.-F. Le Goff, C. Sanchez, N. Mézailles, Chem. - A Eur. J. 2012, 18, 14165.

In this study, a self-generated carbon coating is described as a new way to deposit a regular thin layer of carbon on the surface of nanopartides. It relies on the soft decomposition of the nanopartides surface native ligands, containing alkyl chains, under inert atmosphere at 400°C, a route particularly suited for oxidation-sensitive nanoparticles. Using 25 nm monodispersed Ni2P nanoparticles as a model phase, we succeeded in forming nonsintered and nonoxidized carbon-coated nanopartides. Electrochemical properties of the resulting Ni₂P/C nanoparticles vs Li are compared with those of bulk Ni₂P. The self-generated carbon coating is found to promote Li uptake by providing a Li-permeable electron-conductive percolating network and by improving the mechanical integrity of the electrode.

S. Carenco, C. Surcin, M. Morcrette, D. Larcher, N. Mézailles, C. Boissière, C. Sanchez, Chem. Mater. 2012, 24, 688.

La famille des phosphures de métaux (alliages M_xP_y), pourtant à la portée du chimiste depuis la Révolution française, demeure mal connue et peu utilisée. Cet article revient sur les causes historiques de cette désaffection.

Les nanosciences offrent aux phosphures de métaux le théâtre idéal pour démontrer leur intérêt fondamental et appliqué. Une voie synthétique reposant sur la réaction d’un précurseur de phosphore très réactif, le phosphore blanc, sur des nanoparticules métalliques est présentée.

S. Carenco, C. Boissière, N. Mézailles, C. Sanchez, Actual. Chim. 2012, 362, 22-28

Metal phosphide nanoparticles exhibit attractive properties compared with their metal (0) counterparts for catalysis, optic devices, magnetism applications, and for lithium batteries, for instance. Only a few synthetic pathways offer control on the shape, size, and composition (phosphorus-to-metal ratio) of the nanoparticles for a wide variety of metals. This chapter focuses on one of these pathways: the use of white phosphorus as a stoichiometric ‘‘P’’ atom donor that is reacted with metal nanoparticles in solution and in mild conditions.

S. Carenco, M. Demange, C. Boissière, C. Sanchez, N. Mézailles, in Mol. Work, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2012, pp. 113–120.