Theoretical study of Reduction Routes of Cobalt (I) precursors toward synthesis of Co Nanocrystals

Maya Guillaumont^a, Hélène Gérard^a, Stéphanie Halbert^a, Marc Petit^b, and Christophe Petit^c
^aLaboratoire de Chimie Théorique, UMR 7616, Paris, France
^bInstitut Parisien de Chimie Moléculaire, UMR 8232, Paris, France
^cMONARIS, UMR 8233, Paris, France Mercredi 30 Janvier 2019, 11h00
bibliothèque LCT, tour 12 - 13, 4^ème étage

Starting from a CoCl(PPh₃)₃ complex, synthesis of monodisperse hcp Cobalt nanoparticles[1] takes place through an original disproportionation path. In this presentation we unravel, toward computational studies of simple models, the role of the oleylamine solvent, the nature of phosphine ligands, and of the halogen anion. Our synergetic computational and experimental analysis provide better understanding on the redox behavior of Cobalt in complex environment, highlighting how nanoparticles formation occurs upon a fine balance of the stabilization of the several oxidation degrees and coordination numbers[2] of the metal center. Comparisons to other reduction processes or to other metal precursors (Ni, Cu) point out the numerous competing processes possibly at stake in this experimental procedure. In a last part, we present our first results toward understanding of the mechanistic aspect of this disproportionation.

[Picture]

Key steps toward synthesis of Cobalt nanocrystals in solution

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Références :
[1] L. Meziane, C. Salzemann, C. Aubert, H. Gérard, C. Petit, and M. Petit, Nanoscale 2016, 8, 18640-18645.
[2] A. Vivien, M. Guillaumont, L. Meziane, C. Salzemann, C. Aubert, S. Halbert, H. Gérard, M. Petit, and C. Petit, Chem. Mater., accepted.