Nicoletta Panziera

Hydrosilylation of aromatic nitriles promoted by solvated rhodium atom-derived catalysts

Abstract Rhodium metal particles, isolated as supported or unsupported powder starting from mesitylene solvated rhodium atoms, catalyse the hydrosilylation of aromatic nitriles to N , N -disilylamines in high conversion at 100°C. Different hydrosilanes (HSiMe 3 , HSi(OEt) 3 ) can be employed. In the case of cinnamonitrile, the chemoselectivity of the reaction to 2-trimethylsilyl-3-phenylpropionitrile and ( E )- and ( Z )-1-di(trimethylsilyl)amino-3-phenyl-1-propene is strongly dependent on the reaction temperature. The commercial rhodium on γ-Al 2 O 3 catalyst is considerably less active and selective than the analogous catalyst prepared via Metal Vapour Synthesis (MVS) probably owing to the different dimension and distribution of the metal particles in the two samples as shown by HRTEM analysis.

Supported Rhodium Nanoparticles in Catalysis: the role of stabilizers on catalytic activity and structural features

Abstract Rhodium nanoparticles supported on γ-Al 2 O 3 , derived from arene-solvated Rh atoms stabilized by trioctylamine (TOA), are valuable catalysts in hydrogenation and silylformylation reactions. They are largely more active than the analogous commercial catalyst, as well as of a sample similarly prepared in the absence of TOA. HRTEM measurements, IR studies on adsorbed CO species and extended X-ray absorption fine structure analyses evidenced the role of TOA in controlling the particle growth in the preparative process and in stabilizing the resulting Rh particles against erosion by CO and oxidation.

Preparation of nanostructured organometallic polymer/palladium hybrids by metal vapour synthesis: structure and morphology

Pd(0) nanoclusters were dispersed by using the metal vapour synthesis technique in organometallic polymers of chemical structure (M = Pd,Pt), namely Pd-DEBP and Pt-DEBP. The hybrids were characterized by means of solid state 13C and 31P nuclear magnetic resonance, which highlighted the chain organization and the plasticizing effect of the nanoparticles on the polymers. Scanning electron microscopy images of the pristine organometallic polymers, and of their hybrids containing Pd(0), exhibited a growth of nanosized fibrils on glass substrates. High resolution transmission electron microscopy measurements showed a narrow distribution of Pd(0) nanoparticles which have dimensions in the range 1.0–5.0 nm in the case of Pd/Pd-DEBP hybrids and 0.5–2.0 nm in the case of Pd/Pt-DEBP hybrids.