New Ligand-Based Metal Complexes: Synthesis, Spectroscopic Characterization, Thermal Behavior, Anticancer Properties, and Biological Activity

Abstract

New ligands, N1, N4-bis (benzo[d]thiazol-2- ylcarbamothioyl) succinamide (L¹) and N1, N4- bis (benzylcarbamothioyl)succinamide (L²), derived from succinyl chloride and 2-amino benzothiazole or benzylamine, respectively, have been used to prepare a set of transition metal complexes with the general formula [M₂(L)Cl₄], where L=L¹ or L², M = Mn(II), Ni(II), Cu(II), Cd(II), Co(II), Zn(II) or Hg(II). The synthesized compounds were characterized using various analytical techniques including TGA, ¹³C NMR, mass spectroscopy, ¹H and Fourier-transform infrared (FTIR) spectroscopy, magnetic measurement, molar conductivity, electronic spectrum, (%M, %C, %H, %N) and atomic absorption flame (AAF) analysis. The results showed that (L¹, L²) bind to the metal ion in a bidentate fashion through the (C=O) and (C=S) groups, and the complexes have a tetrahedral geometry. The antibacterial activity of the compounds was tested against two types of bacteria, Escherichia coli (−) and Staphylococcus aureus (+). Additionally, the anticancer activity of the Cu(II) and Co(II) complexes was evaluated by carrying out cell viability and cytotoxicity assays on the MCF-7 breast cancer cell line and comparing the results with those obtained for normal cells.