Designed synthesis of copper(II) and nickel(II) complexes with a tridentate N2O donor Schiff base: Modulation of crystalline architectures through CH⋯π and anion⋯π interactions

Two copper(II) complexes, Cu(L1)Cl (1), Cu(L1)NCS (3) and two nickel(II) complexes Ni(L1)Cl (2), Ni(L1)NCS (4), where HL1 = 1-[(2-diethylamino-ethylimino)-methyl]-naphthalen-2-ol act as tridentate N2O donor ligand, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. The geometry of the central metal ion in each of the four complexes is square planar. The existence of CH⋯π interactions in 2 gives rise to one dimensional chain structure. Complex 3 shows two CH⋯π interactions and one anion⋯π interactions which leads to a two dimensional layer structure. Each mononuclear unit of 4 has two CH⋯π interactions along b axis to form a double strand one dimensional array of the molecules in crystal packing.