Study of Metal-1,10-Phenanthroline Complex Equilibria by Potentiometric Measurements

The interaction of Sc(III), Y(III), and La(III) ions with 1,10-phenanthroline (Phen) has been investigated, using the potentiometric method at 25 ± 0.1°C and I=0.10 M KNO3. Collected potentiometric data were processed by the “BEST” software program to establish the complexation model for each system. SPE software program was used to evaluate the concentration distributions of the species formed in solution. The stability constants for the binary complexes increased as the ionic radii of the metal cations decreased.