Présentation de Laura Hippolyte

Pertinence des Carbènes Boranes comme réducteurs et source de groupement de surface dans une synthèse innovante de nanoparticules et nanoclusters d’or

L. Hippolyte1,2*, N. Bridonneau1, D. Mercier3, D. Portehault1, M. Desage-El Murr2, L. Fensterbank2, C. Chanéac1, F. Ribot1

(1) Sorbonne Université, CNRS, Collège de France, Laboratoire Chimie de la Matière Condensée de Paris, LCMCP, F-75005 Paris, France
(2) Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005 Paris, France
(3) PSL Research University, Chimie ParisTech, CNRS, Institut de Recherche de Chimie Paris, IRCP, F-75005 Paris, France 

Abstracts

Gold nanoparticles have been known for a long time and have found applications in many fields such as medicine, optics, electronics or catalysis. Their most common syntheses generally require three components: a gold precursor, a reducing agent and a stabilizing ligand. N-Heterocyclic carbenes (NHCs) are persistent carbenes with highly tunable structures. In recent years their chemistry has blossomed and they have shown a strong affinity for a wide range of metals1. In the case of gold, this affinity has been shown to be higher than with thiols2. A few studies have shown the possibility to use NHCs to stabilize gold nanoparticles3-5, starting from NHC-gold complexes, (benz)imidazolium-gold complexes or by exchanging a sacrificial ligand with free NHCs.

NHCs, which are Lewis bases, can also form with borane (Lewis acid) stable adducts6, which exhibit reducing properties. NHC-boranes were thus explored as "2-in-1" reagents, ie. reducing agent and source of stabilizing ligands, in the synthesis of gold nanoparticles. A synthesis of NHCs stabilized gold nanoparticles is reported for the first time from NHC-boranes and AuClSMe2 as gold precursor7. XPS analysis confirms the presence of NHCs as surface ligands. Varying the reaction conditions allows tuning the average nanoparticle size in the range 5-10 nm.

Figure 1. Scheme of the nanoparticles synthesis, TEM image of obtained nanoparticles and corresponding size distribution
Figure 1. Scheme of the nanoparticles synthesis, TEM image of obtained nanoparticles and corresponding size distribution
References
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  6. D.P. Curran, A. Solovyev, M. Makhlouf Brahmi et al., Angew. Chem. Int. Ed. 50, 10294 (2011).
  7. L. Hippolyte, N. Bridonneau, F. Ribot, et al., manuscript in preparation  Corresponding author email: laura.hippolyte@upmc.fr