THE INTRAMOLECULAR AROMATIC-RING STACKING INTERACTION OF THE TERNARY MIXEDLIGAND COMPLEXES:STUDY OF Pd2+-HETEROCYCLIC RING BASE-NUCLEOTIDE SYSTEM BY POTENTIOMETRIC pH TITRATION

One of the typical phenomena of intramolecular ligand-ligand interaction in complexes is the aromatic-ring stacking which depends on the stacking of those non-coordinating aromatic rings. Since 1974 H. Sigel reported that the stacking interaction was observed between pyridine ring of bpy(bpy=2, 2′-bipyridyl) and purine ring of ATP(ATP=adenosine 5′-triphosphate) among the mixed-ligand Cu(bpy) (ATP)complexes. The study on this field has been extended to a large amount of ligands such as nucleotides, xanthosines, amino