Building block approach to organic silica hybrid materials

The reaction of the cubic octameric silicate anion, Si8O208-, with dimethyldichlorosilane in 2,2-dimethoxypropane yielded solid products. FT-IR and solid-state Si-29 NMR spectra of the products indicate that the silicate anion becomes cross-linked via the dimethylsilyl group without degradation of the cubic core, resulting in the formation of organic/silica hybrids consisting of the Si8O208- structure as a building block. The hybrids are thermally stable up to ca. 380 degrees C in air. The specific surface area of the hybrids is 31 m(2) g(-1), while the value increases to 339 m(2) g(-1) after calcination at 350 degrees C in air. The process of increasing the surface area of the hybrids by the heat-treatment was investigated using solid-state C-13 NMR spectroscopy.