A series of new layered inorganic-organic nanocomposites, with organic functionalities directly bonded to an inorganic framework via the Si-C bond, were prepared by a template sol-gel synthesis. These layered Al- and Mg-silsesquioxanes were precipitated at room temperature by addition of aqueous base to an alcohol solution containing a mixture of AlCl3 or MgCl2 and a trialkoxysilane with a n-dodecyl, n-octyl, n-pentyl, 3-methacryloxypropyl, isobutyl, or phenyl functionality. The Si/Al and Si/Mg ratios of the reaction mixtures were 2:1 and 4:3, respectively, and were chosen to match the composition of clay mineral pyrophyllite (layered aluminosilicate) and talc (layered magnesiosilicate).