Thermodynamics of mixed-ligand complex formation of samarium(III) and cerium(III) ethylenediaminetetraacetates with various ligands in aqueous solution

Abstract

The thermodynamic parameters of reaction (logK, Δr G 0, Δr H, Δr S) are determined for the mixed-ligand complex formation of SmEdta− and CeEdta− with glycinate, iminodiacetate, aspartate, and nitrilotriacetate ions in aqueous solution at 298.15 K and ionic strength of I = 0.5 (KNO3). Based on these thermodynamic data, the most likely coordination modes are suggested for the complexone and the ancillary ligand in the mixed-ligand complexes.