The present invention relates to 1,3-oxathiolane-2-thione compounds of the general formula (I): wherein R1 and R2 are the same or different, each of which denotes a straight-chain or branched alkoxy residue with 1 to 6 carbon atoms or an aryloxy or aralkyloxy residue, R3 is different or the same as R1 or R2 or an aliphatic residue, an amino residue, a halogen residue, an aromatic or heteroaromatic residue, or an araliphatic or heteroaraliphatic residue, R4 is a bridging group selected from the groups consisting of aliphatic, heteroaliphatic, araliphatic, heteroaraliphatic, aromatic and heteroaromatic groups and R5 is hydrogen, an aliphatic, heteroaliphatic, araliphatic, heteroaraliphatic, aromatic, heteroaromatic, cycloaliphatic or heterocycloaliphatic group or R4 and R5 form a cycloaliphatic, cycloheteroaliphatic, aromatic or heteroaromatic residue, which is optionally substituted with an aliphatic, heteroaliphatic residue serving as a bridging group to the silicon atom and X and Y are different and selected from oxygen and sulfur and mixtures of such compounds.