Ternary complexes: equilibrium studies of mixed-ligand complexes of uranyl ion with dicarboxylic acids in aqueous solution

Abstract

The stability constants of the ternary uranyl ion complexes involving dicarboxylic acids were determined by pH metric titrations at a temperature of 31±0.1°C and an ionic strength, μ=0.1 M (NaClO₄). The stability values clearly show the discriminating qualities of uranyl ion-dibasic acid 1:1 complex toward the secondary ligand to be coordinated. The values of log K_2YX are inversely related to the product of the acid dissociation constants of the secondary ligands. The overall stability is found to be dependent on the binary stabilities. Ring size of the chelates formed by the secondary ligands is found to influence the formation of ternary complexes.