PREPARATION OF SILICAS COMBINED WITH OPTICALLY-ACTIVE ORGANIC-COMPOUNDS - OPTICAL RESOLUTION OF METAL CHELATE COMPLEXES ON THE SILICA COMPOSITES

A new type of optically active organic-inorganic composite was prepare d by a sol-gel method in which tetraethoxysilane is hydrolysed after r eplacing the ethoxy group with D-lactose or L-tartaric acid, and compa red in the optical resolution of tris(2,4-pentanedionato)metal complex es with conventional silica composites (kneading with L-lactose and im pregnation with an L-lactose or L-tartaric acid solution) and the orga nic compounds themselves. The sol-gel composites showed much higher op tical resolution abilities than the conventional materials and, in add ition the optically active organic compounds could not resolve the rac emate under similar conditions. The high resolution ability of the sol -gel composites was deduced to come from the combined effect of silica and a dispersed optically active organic compound.