Non-Oxide Sol–Gel Chemistry: Preparation from Tris(dialkylamino)silazanes of a Carbon-Free, Porous, Silicon Diimide Gel

The acid-catalyzed ammonolysis of the hitherto unknown compound tris(dimethylamino)silylamine (1), which is prepared from SiCl₄ in high yield and purity, results in the preparation of a silicon diimide gel. The probable first step in this process is the acid-catalyzed self-condensation of 1 to the cyclic trimer [{(CH₃)₂N}₂SiNH]₃. This ammonolysis under mild conditions in THF provides a semirigid translucent gel. On drying under mild conditions in an ammonia atmosphere this non-oxide gel yields a high surface area silicon diimide xerogel that is the first example of a porous non-oxide silicate gel.