| abstract |
Compounds of general formula (I), where n and m each represent the numbers 0, 1, 2, 3 and 4, X represents a hydrogen atom and / or an equivalent in metal ions of an element of ordinal numbers 21 -29, 31, 32, 37-39, 42-44, 49 or 57-83, R1 and R2 are different and each represents a hydrogen atom or a C0-C20 alkylene group with straight or branched chain, saturated or unsaturated , optionally containing one or more imino, phenyleneoxy, phenyleneimino, amido, hydrazido, ester, one or more oxygen, sulfur and / or nitrogen atoms, and optionally substituted by one or more hydroxy, mercapto, imino groups, epoxy, oxo, thioxo, and / or amino, said group having at its end a second molecule of general formula (IA) or (IB), a functional group or else, linked via this functional group, a bio- or macromolecule, provided that the sum of n and m is not more than 4 and that, when X represents an equivalent in metal ions, at least two of the X substituents have this notation, as well as their salts with inorganic or organic bases or amino acids are valuable diagnostic and therapeutic agents. |