Synthesis of a multifunctional alkoxysiloxane oligomerElectronic supplementary information (ESI) available. See DOI: 10.1039/c4nj00204k

An alkoxysiloxane oligomer ( 1 , SiMe[OSi(CH&z.dbd;CH 2 )(OMe) 2 ][OSi(CH 2 ) 3 Cl(OMe) 2 ] 2 ), containing vinyl and chloropropyl groups, was synthesized as a precursor for sol-gel synthesis. Di- tert -butoxymethylhydroxysilane ( t -BuO) 2 MeSiOH was reacted with (MeO) 2 (CH 2 &z.dbd;CH)SiCl to form ( t -BuO) 2 MeSiOSi(CH&z.dbd;CH 2 )(OMe) 2 which was further alkoxysilylated with Cl(CH 2 ) 3 SiCl(OMe) 2 to form 1 . The 1 H, 13 C, 29 Si NMR and HR-MS data confirmed the formation of 1 , indicating the successful synthesis of an alkoxysiloxane oligomer possessing different kinds of functional groups by a chemoselective route. Hydrolysis of 1 under acidic conditions was completed in a few hours. The solution state 29 Si NMR spectra of samples hydrolyzed and condensed at various reaction times show no signals due to species generated by the cleavage of the siloxane bonds in 1 , indicating the validity of the synthesized substance as a precursor for the formation of hybrids with homogeneously distributed functional groups. Intramolecular condensation of 1 to form cyclic trisiloxane units proceeds more preferentially than intermolecular condensation. The siloxane bonds of oligomer 1 were not cleaved by hydrolysis, indicating the suitability of 1 for controlled hybrid preparation.