Treatment of tetramethoxysilane with glycolic acid and morpholine (molar ratio 1:3:2) in methanol, followed by crystallization from methanol/tetrahydrofuran, yielded morpholinium mer-tris[glycolato(2-)-O-1,O-2]silicate (mer-7). Treatment of benzilic acid with sodium hydride, followed by addition of tetrachlorosilane and triethylamine (molar ratio 3:41:2), afforded, after crystallization from 1,4-dioxane/acetonitrile/diethyl ether/n-pentane, triethylammonium fac-tris[benzilato(2-)-O-1,O-2]silicate-hemi-1,4-dioxane (fac-8(.1)/2C4H8O2). Single-crystal X-ray diffraction studies showed that the Si-coordination polyhedra of the hexacoordinate silicon(IV) complexes mer-7 and fac-8(.1)/2C4H8O2 are distorted octahedra. Both compounds were additionally characterized by solid-state VACP/MAS NMR studies (C-13, Si-29), and fac-8(.1)/2C4H8O2 was studied in solution by H-1, C-13, and Si-29 NMR experiments. The structural investigations were complemented by computational studies (MP2 studies, TZP level) of the dianions of fac-7 and mer-7.