Gr. Choppin et al., COMPLEXATION THERMODYNAMICS OF LANTHANIDE IONS BY BENZENEPOLYCARBOXYLATE LIGANDS, Journal of coordination chemistry, 31(4), 1994, pp. 297-304
The complexation thermodynamics of lanthanide ions by 1,2,3-benzenetri
carboxylate (hemimellitate), 1,2,4-benzenetricarboxylate (trimellitate
) and 1,2,4,5-benzenetetracarboxylate (pyromellitate) ligands were stu
died using potentiometric, calorimetric and extraction techniques. The
measurements were obtained at an ionic strength of 0.10 M (NaClO4) an
d at 25-degrees-C. The results were compared to analogous values of be
nzoate, isophthalate and o-phthalate complexation. The apparent increa
sed stability of these complexes above that expected for a typical bid
entate complex is in fact merely a statistical factor. The DELTAH101 a
nd DELTAS101 of these complexes reflect relatively strong dehydration
of metal and ligand ions upon complex formation.