The stability constants of PdAB ternary complexes were determined by potentionmetric pH titration at 25℃,I=0.1mol/l KNO3,whereA=2,2′-bipyridy1-3,3′-dicarboxylicacid,B=Alanine,3,5-Dibr-tyrosine and 3,5-DiI-tyrosine.The binary complexes stability constants have also been determined at the same conditions.And compared with alanine,tyrosine system,the possible reasons that lead to extra stability of ternary complexes were discussed from the viewpoint of aromatic ring stacking,d-pπbond or hydrogen-bond.
