1,3-Dimethyl-tetrakis(2-triphenylsilylethyl)dimethyldisiloxane: a new carbosilane for the preparation of high-refractive-index films

A new carbosilane has been synthesised in one step by hydrosilylation of 1,3-dimethyl-tetravinyldisiloxane with triphenyl silane. The new carbosilane has been characterized by 1D and 2D NMR, MS, and Gel Permeation Chromatography (GPC). The new carbosilane has been spin-coated on silicon wafers to prepare a film with very high refractive index (μ = 1.520) and excellent hydrophobicity. The film has also been analysed by Diffuse Reflectance Infrared Spectroscopy (DRIFT). The preparation of the new carbosilane does not generate waste, and its application can be easily scaled-up. Consequently, the new precursor is likely to be very useful for industrial optoelectronic applications.

Phosphorus dendrimers functionalised with nitrogen ligands, for catalysis and biology

Phosphorus dendrimers (dendrimers having one phosphorus atom at each branching point) possess versatile properties, depending on the type of their terminal functions.

Extremely efficient catalysis of carbon-carbon bond formation using "click" dendrimer-stabilized palladium nanoparticles

This article is an account of the work carried out in the authors' laboratory illustrating the usefulness of dendrimer design for nanoparticle palladium catalysis. The "click" synthesis of dendrimers constructed generation by generation by 1-->3 C connectivity, introduces 1,2,3-triazolyl ligands insides the dendrimers at each generation. Complexation of the ligands by Pd(II) followed by reduction to Pd(0) forms dendrimer-stabilized Pd nanoparticles (PdNPs) that are extremely reactive in the catalysis of olefin hydrogenation and C-C bond coupling reactions. The stabilization can be outer-dendritic for the small zeroth-generation dendrimer or intra-dendritic for the larger first- and second-generation dendrimers. The example of the Miyaura-Suzuki reaction that can be catalyzed by down to 1 ppm of PdNPs with a "homeopathic" mechanism (the less, the better) is illustrated here, including catalysis in aqueous solvents.