Hybrid catalysts for acetylenes polymerization prepared by anchoring [Rh(cod)Cl]2 on MCM-41, MCM-48 and SBA-15 mesoporous molecular sieves -: The effect of support structure on catalytic activity in polymerization of phenylacetylene and 4-ethynyl-N-{4-[(trimethylsilyl)-ethynyl]benzylidene}aniline

Hybrid catalysts for polymerization of acetylenes were prepared by anchoring, via (3-aminopropyl) trimethoxysilane linker, the [Rh(cod)Cl](2) complex on siliceous mesoporous molecular sieves differing in the pore size and architecture (MCM-41, MCM-48 and SBA-15). In comparison with [Rh(cod)Cl](2) used as homogeneous catalyst, all hybrid catalysts exhibited comparable or even higher catalytic activity in the polymerization of phenylacetylene and 4-ethynyl-N-{4-[(trimethylsilyl)ethynyl]benzylidene}aniline. The initial polymerization rate increased with increasing accessibility of mesoporous surface of catalysts in the order: MCM-41 < MCM-48 < SBA-15. Molecular weights of the prepared polymers increased in reverse order suggesting suppression of the chain growth termination reactions by space limitations in the pores. No effect of catalyst support on the microstructure of formed polymers was found.