Ni(II), Cu(II) and Zn(II) complexes of (Z)-N′(1,3,4-thiadiazol-2-yl) acetimidate: Synthesis, spectral, solid state electrical conductivity, X-ray diffraction and DFT study

Abstract

The in situ generated new ligand (Z)-N′(1,3,4-thiadiazol-2-yl) acetimidate (tha) formed complexes [Ni(tha)2] (1), [Cu(tha)2] (2) and [Zn(tha)2] (3) in one pot condensation reactions between metal(II) acetate and 2-amino-1,3,4-thiadiazole. The complexes have been characterized with the aid of elemental analyses, IR, Raman, magnetic susceptibility and single crystal X-ray data. The metal complexes 1, 2 and 3 crystallize in monoclinic system with space group P21/c. In the complexes, the newly generated ligand is bonded through thiadiazole ring nitrogen and oxygen of acitimidate group, thus acting as N, O bidentate ligand producing a six membered chelate ring. Ni(II), Cu(II) and Zn(II) complexes of the type [ML2] contain extended hydrogen bonding providing supramolecular architecture. Various types of π–π interactions are responsible for the semiconducting behavior of the complexes and also stabilize their crystal structures. The geometry optimization has been performed using DFT method and geometrical parameters thus obtained for the complexes have been compared with their single crystal XRD structures. The molecular electrostatic potential (MEP) and contour maps of the ligand and the complexes are also calculated by DFT method.