Ni(II) and Zn(II) complexes of 2-((thiophen-2-ylmethylene)amino)benzamide: Synthesis, spectroscopic characterization, thermal, DFT and anticancer activities

Abstract The paper presents the synthesis of Ni(II) and Zn(II) complexes of general composition M(L)X 2 and M(L) 2 X 2 (M = Ni(II), Zn(II), X = Cl −1 , OAc −1 ) with Schiff base obtained through the condensation of 2-aminobenzamide with thiophene-2-carbaldehyde. The characterization of newly formed complexes was done by 1 H NMR, UV–VIS, TGA, IR, mass spectrophotometry and molar conductivity studies. The thermal studies suggested that the complexes are more stable as compared to ligand. In DFT studies the geometries of Schiff’s base and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. On the basis of the spectral studies a distorted octahedral geometry has been assigned for Ni(II) complexes and tetrahedral geometry for Zn(II) complexes. The effect of these complexes on proliferation of human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (HepG2) were studied and compared with those of free ligand.