Molecular recognition ability is one of the properties exhibited by a composite presented here consisting of an optically active organic compound (L-tartaric acid) and silica. It is reported that the composite formed by the sol-gel method can distinguish the chirality of the complex tris(2,4-pentanedionato)cobalt(III). The reasons for the differing properties of the composites formed by impregnation and the sol-gel method are discussed and circular dichroism spectra presented.