Synthesis of cage-like octa(trimethylsiloxy)silsesquioxane

Cage-like octa(trimethylsiloxy)silsesquioxane [ (Me₃SiO)SiO_1.5]₈ has been synthesized via the trimethylsilylation of cubic tetramethylammonium silicate octamer [(Me₄NO)-SiO_1.5]₈ with chlorotrimethylsilane. The silicate octamer can be selectively formed by the reaction of tetraethoxysilane Si(OEt)₄ with aqueous tetramethylammonium hydroxide in equal molar ratio. Elementary analysis, FT-IR,¹H,¹³C,²⁹Si NMR are used to characterize these silsesquioxanes.