Copper metallic particles are formed and get anchored in the siloxane oligorner obtained during the reaction of phenylsilane and ethyleneglycol with bis-pyridinium, tetrachlorocopper(II). These supported metallic copper particles can catalyse the coupling reactions of silanes with alcohols. cis-Butenediol reacts with diphenylsilane or methylphenylsilane in the presence of bis-pyridinium tetrachlorocopper(II) and gives siloxane oligomers. The double bonds of the parent monomers are retained in these siloxanes. The bis-pyridinium tetrachlorocopper(II) catalysed reactions involve Cu(I)Cu(II) couple and colloidal metallic particles. Triphenylsilylethyl ether is formed in the catalytic reaction of silver nitrate with triphenylsilane in ethanol. In this reaction silver particles gets attached to the silylether. (c) 2005 Elsevier B.V. All rights reserved.