Germanium-substituted silicate cages as precursors of organosilyl-functionalized open-cage siloxanes

Abstract Here, we propose a method for synthesizing a new type of open-cage siloxane modified with organosilyl groups via silylation of Ge-substituted silicate cages. Ge-substituted silicate cages are formed from silicate octamers (Si8O208−) and GeO2 in an aqueous solution containing tetramethylammonium hydroxide. Silylation of the mono-Ge-substituted cages with chlorosilanes enables both Ge removal through Si–O–Ge bond cleavage and the introduction of functional organosilyl groups. The resulting open-cage siloxane compound is promising as a nano-building block for functional nanomaterials.