Methionine isomers and the stability of their complexes with uranyl, thorium and some transitional metal ions

Stability constants of complexes formed between optically pure isomers of methionine and uranyl, thorium and divalent cations, Cu2+, Ni2+, Zn2+, Co2+, Cd2+ at 25 deg C and an ionic background of 0.1M KNO3 have been determined by potentiometric titration. The racemic mixture prepared by mixing solution of the pure isomers in equal quantity and the constants measured showed no conclusive evidence of stereoselectivity. Over the used concentration ranges tris-complexes did not form in significant amount. (author)