Vanadyl(IV) Complexes of Lactobionic Acid: Potentiometric and Spectroscopic Studies

Abstract Potentiometric and spectroscopic studies have shown that in the VO(IV)-lactobionic acid system five different species are involved in coordination equilibria. All complexes consist of one metal ion and two ligand molecules. Stability constants for the vanadyl complexes with lactobionic acid are considerably higher than those for uronic acids, although the donor atoms involved in metal ion coordination are exactly the same. The main reason for the higher stability of lactobionic acid complexes seems to concern its more flexible structure.