MIXED-LIGAND COMPLEXES OF SOME DIVALENT TRANSITION-METAL IONS WITH DICARBOXYLIC AMINO-ACIDS AND 8-HYDROXYQUINOLINE

Mixed-ligand complexes of Co-II, Ni-II, and Cu-II with dicarboxylic am ino acids (aspartic and glutamic or H(2)ADA) as primary ligands and 8- hydroxyquinoline as a secondary ligand were prepared and characterized . Formation constants of the different complexes were determined acidi metrically at 25 degrees C and at ionic strength I = 0.1 mol dm(-3) (K NO3) and were discussed in terms of the nature of both the metal ion a nd the ligand used. The thermodynamic functions (Delta H, Delta G degr ees, and Delta S degrees) associated with the formation of [M-II + (HA DA)(1-)+ 8-hydroxyquinoline] complexes were also calculated and discus sed.