Synthesis of octacarboxy spherosilicate.

feasible new preparation was reported for an octacarboxylphenyl functionalized spherosilicate, octakis[(pcarboxyphenyl) dimethylsilyl]silicate, which was a versatile monomer leading to other functional spherosilicate derivatives. The synthesis was started from octakis[dimethyl(p-methylphenyl)silyl]silicate. Octakis[dimethyl(pmethylphenyl) silyl]silicate was brominated by NBS to produce octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate. Finally, octakis[dimethyl(4-tribromomethylphenyl)silyl]silicate was hydrolyzed in the presence of AgNO3 and formic acid to give the desired compound. Octakis[(pcarboxyphenyl) dimethylsilyl]silicate was fully characterized by FTIR, 1H NMR, 13C NMR, 29Si NMR spectra, ESI-MS, and elemental analysis.