(Trialkoxysilyl)tetrathiafulvalenes: Precursors of Organized Organic‐Inorganic Hybrid Materials by Sol‐Gel Chemistry

The synthesis, characterization and electrochemical behaviour of novel monomers for use in sol-gel processes are described. These new compounds include a rigid tetrathiafulvalene (TTF) core substituted by one or two spacers, to which a triethoxysilyl group is covalently bonded. The synthesis is based on the preparation of various cyanoethyl-protected TTF thiolates, deprotection and alkylation of thiolate with 2-bromoethanol, and subsequent condensation of the alcohol function with 3-(triethoxysilyl)propyl isocyanate. The donor ability of the title compounds has been investigated by electrochemical studies. The hydrolytic polycondensation of these new precursors was performed in THF solution in the presence of nucleophile (tetrabutylammonium fluoride, TBAF) or acid (HCl) catalysts. The resulting hybrid solids are highly polycondensed and present organization at both the nanometric (X-ray diffraction) and micrometric (birefringence) scales. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)