Determination of UO2(II), Th(IV) and Ce(III) complexes formed with halogenand nitro derivatives of 8-hydroxyquinoline

Proton-ligand stability constants for some iodo and nitro derivatives of 8- hydroxyquinoline were determined by Calvin Bjerrum potantiometric method. T he stability constants of the corresponding chelates with UO2 (II), Th(IV) and Ce(III) were studied potentiometrically at 25 degreesC by applying Irvi ng-Rossotti computing method. The complexes of the nitro-substituted ligand s were less stable than the corresponding complexes of the unsubstituted li gands. The stability constants of metal-ligands depend on the ionic radii a nd ionic charge of metals and also they decrease with steric repulsions of the nitro groups.