Stability constants of ternary complexes of dioxouranium(VI) with phthalic acid and O-, O-, O-, N and N, N donor ligands

The ternary complexes of uranyl ion with phthalic acid (common ligand) and different ligands capable of complexing through O-, O- (oxalic, maleic, fumaric, succinic and salicylic acids and pyrocatechol), O-, N(8-hydroxyquinoline and o-aminophenol) or N, N(2,2'-bipyridyl and ethylenediamine) have been investivated pH-metrically at 25degC and μ = 0.1M (KNO3) in aqueous medium. The stability constants of the ternary complexes have been evaluated by different methods depending on the nature of interaction between metal ion and the ligands. The results have been discussed in terms of donor atoms, sizes of the chelate rings, and electrostatic and metal-ligand interactions. (author)