title: Ruthenium nanoparticles in ionic liquids: structural and stability effects of polar solutes.
abstract: Ionic liquids are a stabilizing medium for the in situ synthesis of ruthenium nanoparticles. Herein we show that the addition of molecular polar solutes to the ionic liquid, even in low concentrations, eliminates the role of the ionic liquid 3D structure in controlling the size of ruthenium nanoparticles, and can induce their aggregation. We have performed the synthesis of ruthenium nanoparticles by decomposition of [Ru(COD)(COT)] in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(1)C(4)Im][NTf(2)], under H(2) in the presence of varying amounts of water or 1-octylamine. For water added during the synthesis of metallic nanoparticles, a decrease of the solubility in the ionic liquid was observed, showed by nanoparticles located at the interface between aqueous and ionic phases. When 1-octylamine is present during the synthesis, stable nanoparticles of a constant size are obtained. When 1-octylamine is added after the synthesis, aggregation of the ruthenium nanoparticles is observed. In order to explain these phenomena, we have explored the molecular interactions between the different species using (13)C-NMR and DOSY (Diffusional Order Spectroscopy) experiments, mixing calorimetry, surface tension measurements and molecular simulations. We conclude that the behaviour of the ruthenium nanoparticles in [C(1)C(4)Im][NTf(2)] in the presence of 1-octylamine depends on the interaction between the ligand and the nanoparticles in terms of the energetics but also of the structural arrangement of the amine at the nanoparticle's surface.
authors: Institut de Chimie de Lyon, UMR 5265 CNRS-Université de Lyon 1-ESCPE Lyon, C2P2, Equipe Chimie Organométallique de Surface, ESCPE 43 Boulevard du 11 Novembre 1918, F-69616 Villeurbanne, France.
authors: Gorka
authors: G
authors: Salas
authors: Ajda
authors: A
authors: Podgoršek
authors: Paul S
authors: PS
authors: Campbell
authors: Catherine C
authors: CC
authors: Santini
authors: Agílio A H
authors: AA
authors: Pádua
authors: Margarida F
authors: MF
authors: Costa Gomes
authors: Karine
authors: K
authors: Philippot
authors: Bruno
authors: B
authors: Chaudret
authors: Mireille
authors: M
authors: Turmine