Trimethylsilyl derivatives for the study of silicate structures. Part II. Orthosilicate, pyrosilicate, and ring structures

A direct method of trimethylsilylation reported previously for hemimorphite was applied to other silicates with well-defined structures. For anhydrous minerals the presence of water in the reaction medium was essential for trimethylsilylation. The effects of water and of time, temperature, and concentration of reagents on the trimethylsilylation were studied. A unified procedure was developed for conversion of orthosilicates to trimethylsilyl derivatives of the anion SiO44–, pyrosilicates to trimethylsilyl derivatives of Si2O76–, and silicates with a tetrameric ring structure to trimethylsilyl derivatives of Si4O128–, and for determination of these structures by gas–liquid partition chromatography.