Copper(II) complexes with tridentate N2O donor Schiff bases: Modulation of crystalline architectures through supramolecular interactions

Three mononuclear copper(11) complexes, [Cu(L-1)(DMF)]ClO4 (1), [Cu(L-2)(DMSO)]ClO4 (2) and [CuL3(NCO)] (3) (where HL1 {2-[(2-methylamino-ethylimino)-methyl]-4-nitro-phenol}, HL2 {2-[(2-ethylamino-ethylimino)-methyl]-4-nitro-phenol) and HL3 {2-[(2-(dimethylamino)ethylimino)methyl]-4-nitrophenol} are tridentate Schiff-base ligands), have been synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy and single-crystal X-ray diffraction studies. All the complexes are square planar. Complex 1 crystallizes in the triclinic space group P (1) over bar, with cell dimensions a = 8.0396(2), b = 9.0892(2), c= 12.9977(3) angstrom, alpha = 85.591(1)degrees, beta = 84.198(1)degrees and gamma = 76.423(1)degrees, whereas complex 2 crystallizes in the orthorhombic space group, Pbca with cell dimensions a = 8.4615(4), b = 17.2708(11) and c= 25.8517(12) angstrom. Complex 3 crystallizes in the monoclinic space group, P2(1/n) with cell dimensions a = 6.9550(3), b = 13.2257(7), c = 14.7755(6) angstrom and beta = 102.697(3)degrees. Both HL1 and HL2 are capable of forming H bonds due to the presence of H atoms in their amine groups. On the other hand, HL3 cannot form H-bonds. The weak forces like H-bonding, lone pair...pi and pi...pi interactions lead to various supramolecular architectures in the complexes. (C) 2013 Elsevier Ltd. All rights reserved.