Catalytic sol-gel co-polycondensation of para-substituted phenylsilanes and bis(silyl)phenylene to robust organosilicas using colloidal nickel nanoparticles.

The dry sol-gel co-polycondensation at toluene in ambient air atmosphere of p-X-C6H4SiH3 (X = H, CH3, CH3O, F, Cl) and p-H3Si-C6H4SiH3 (9:1 mole ratio) to co-silicas (p-X-C6H4SiO1.5)9(p-O1.5Si-C6H4SiO1.5)1 in high yield, catalyzed by colloidal nickel nanoparticles in-situ generated from nickelocene(II) is described. The co-gels (p-X-C6H4SiO1.5)9(p-O1.5Si-C6H4SiO1.5)1 with higher molecular weights and TGA residue yield were obtained when compared to the homogels p-X-C6H4SiO1.5 Some degree of unreacted Si-H bonds still remained in the gel matrix because of steric bulkiness. All the insoluble gels adopt an amorphous structure with a smooth surface. A plausible mechanism for the dry sol-gel reaction was provided.