The chelate rings of transition metals complexes tend to stack in parallel-displaced orientation in chelate-chelate or chelate-aromatic ligand manner similar to stacking interactions between the aromatic rings [1]. Such stacking is the dominant intermolecular interaction in the square-pyramidal complexes of copper(II) with planar [Cu(acac)(AA)] fragment, (acac = acetylacetonate, AA denotes 1,10-phenanthroline (phen) or 2,2´-bipyridine (2,2’-bpy)) and thus represents the reliable supramolecular synthon suitable to generate robust supramolecular motif [2].  The crystal structures of seven novel complexes of copper(II) containing [Cu(acac)(AA)] fragment have been studied to analyze their stacking interactions. The mono- and binuclear complexes with composition [Cu(acac)(phen)(dmf)]BF4 (1), [Cu(acac)(phen)H2O]BF4 (2), Cu(acac)(phen)Cl]MeOH (3), [Cu2(acac)2(phen)2(4,4´-bpy)](BF4)2 (4), [Cu2(acac)2(2,2´-bpy)2(4,4´-bpy)](BF4)2 (5), [Cu2(acac)2(2,2´-bpy)2(bpe)](BF4)2(H2O)2 (6) and [[Cu(acac)(2,2‘-bpy)(H2O)][Cu(acac)(2,2‘-bpy)]](BF4)2 (7) reveal square-pyramidal environment of copper(II) where the equatorial planes are fixed by the acetylacetonate and phen or 2,2‘-bpy chelate ligands, which form five- and six-membered metallacycles, respectively. The face-to-face intermolecular π–π stacking interactions between the center symmetry related complexes have been observed for studied compounds. However the overlapping between the moieties of molecules involving in stacking is different.  The electronic structures of 1-7 compounds have been calculated by Density Functional Theory of Gaussian09 suite of quantum chemical codes [3] to clarify the nature of stacking interactions in these compounds. It was found that dipole-dipole interactions provided the stacking arrangement in 1-7. Both the natural bond orbital (NBO) and topological analysis (AIM theory, [4]) revealed the charge transfer from the localized NBOs into the empty non-Lewis orbitals of fragments involving in the intermolecular π–π interactions.