Cage octaphenylsilsesquioxane from cyclic tetrasiloxanetetraol and its sodium salt

Cage octasilsesquioxane with various substituents were obtained by the condensation reaction of various all-cis cyclic tetrasiloxanetetraol (R-T-4-tetraol, R = phenyl, p-tolyl, i-butyl, naphthyl) with benzyltrimethylammonium hydroxide or tetrabutylammonium fluoride as a catalyst. Co-condensation of phenyl-T-4-tetraol with phenyl-d(5)-T-4-tetraol or with p-tolyl-T-4-tetraol were found to proceed through reshuffling process evidenced by scrambling of the substituents. Pure octa(4-bromo-substituted phenyl)octasilsesquioxane was synthesized for the first time from tetra(4-bromo-substituted phenyl)tetrasiloxanetetraol sodium salt. (C) 2010 Elsevier B.V. All rights reserved.