Synthesis, characterization and DFT study of nickel(II) complexes of a N2O donor Schiff base with different pseudo-halides: Formation of supra-molecular architectures by C–H⋯π interactions

Four new mono-nuclear square planar nickel(II) complexes [Ni(L)(N3)] (1), [Ni(L)(NCO)] (2), [Ni(L)(NCS)] (3) and [Ni(L)(NCSe)] (4), where HL = 2-(1-(2-(diethylamino)ethylimino)ethyl)naphthalen-1-ol, have been synthesized and characterized by elemental analysis, IR, UV–Vis, fluorescence spectroscopy and single crystal X-ray diffraction studies. The ligand is so designed that there is no possibility of hydrogen bonding interactions in all the four complexes. However, the C–H⋯π interactions lead to the formation of one-dimensional chain in complex 2 and two-dimensional sheets in the other three complexes. The geometries of all complexes are optimized in the singlet ground states by DFT calculation. Electronic spectra of the complexes are explained using TD DFT calculation.

Graphical abstractA N2O donor tridentate Schiff base is used to prepare four new mononuclear square-planar nickel(II) complexes with several pseudo-halides. The C–H⋯π interactions lead to various supramolecular architectures. The geometries of all complexes are optimized in the singlet ground states by DFT calculation.Figure optionsDownload full-size imageDownload as PowerPoint slide