The ternary complexes
were obtained as monomers of the type [Cu(pAb)2(phen)] [pAbH = 4-aminobenzoic acid,
phen = unsubstituted phenanthroline
as
a function of the condition of the reaction, as well as a function of the position of
the substituents on the phenanthroline ligand. The formation of aromatic ring stacking
interaction is a function of the geometry of the coordination sphere, as well as of the
substituents on the phenanthroline ligand.