Copper(II) complexes with tridentate N2O donor Schiff base isomers: Modulation of molecular and crystalline architectures through supramolecular interactions

Four copper(II) complexes, [Cu(L1)(μ-Cl)]n (1), [Cu2(L2)2(μ-Cl)2] (2), [Cu(L1)(μ1,5-NCNCN)]n (3) and [Cu(L2)(μ1,5-NCNCN)]n (4), where HL1 = 1-[(2-dimethylamino-ethylimino)-methyl]-naphthalen-2-ol and HL2 = 1-[(2-ethylamino-ethylimino)-methyl]-naphthalen-2-ol, acting as tridentate N2O donor ligands, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complexes 1, 3 and 4 show polymeric chain structures, whereas 2 has a double chloride bridged dimeric structure. The existence of C–H⋯π interactions between the dimeric units of 2 gives rise to a 2D supramolecular network. Complex 3 shows a zipper structure through π⋯π interactions between two polymeric chains. Complex 4 shows hydrogen bonding interactions which produces a 2D hydrogen bonded structure and these 2D layers then show interlayer π⋯π interactions.

Graphical abstractFour copper(II) complexes have been prepared using two tridentate N2O donor Schiff base isomers. Among these four copper(II) complexes, both dicyanamide complexes (3 and 4) show polymeric chain structures, whereas one chloride complex is a double chloride bridged dimer (2) and the other has a polymeric chain structure (1). Supramolecular interactions modulate the molecular as well as crystalline architectures of the complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide