Synthesis, spectral characterization, optical properties and X-ray structural studies of S centrosymmetric N2S2 or N2S2O2 donor Schiff base ligand and its binuclear transition metal complexes

Abstract

A new chelate namely 2,2′-thiobis(N\\-thiophen-2-ylmethyylene) acetohydrazide) (H2TTAH) was synthesized and its metal complexes with Co (II), Ni (II), Cu (II), and Zn (II) ions. The isolated complexes were characterized by conventional spectroscopic (IR, UV-visible, ESR, 1H, 13C-NMR, and mass), elemental analysis, and magnetic as well as thermal measurements. H2TTAH binds either as neutral tetra-dentate and mono- or dibasic NNOOSS hexadentate coordinating two metal ions. The metal complexes afforded the formulae: [Cu2(TTAH)Cl3(C2H5OH)3]0.5C2H5OH.H2O (1), [Co2(TTAH)(C5H5N)]Cl2.2.5C2H5OH (2), [Ni2(TTAH)(C5H5N)2(OH)2(C2H5OH)2] (3) and [Zn2(TTAH)2)(OH)4(C5H5N)2].C2H5OH (4). On the premise of their electronic spectra and magnetic moments data; tetrahedral for Co (II) and octahedral geometries for other complexes were suggested. X-ray powder diffraction technique was used to obtain more details of the chemical constitution of (2) complex. The geometries of all studied compounds were further affirmed by DFT method calculations. Also, all compounds were examined for their antibacterial and superoxide dismutase (SOD)-like activities.