Binuclear Co(II), Ni(II) and Cu(II) acetate complexes derived from a novel Thiosemicarbazide:Preparation, characterization, DFT and In vitro cytotoxicity activity

A new series of binuclear complexes, Co2+, Ni2+and Cu2+ derived from N, N'-(2,2' malonylbis(hydrazine-1-carbonothioyl)) dibenzamide (H4MHTS) in 1:2 (L:M) ratio was prepared and characterized. The complexes adopted the molecular formulae; [Co2(H2MHTS)(OAc)2].2H2O, [Ni2(H2MHTS)(EtOH)4(H2O)2] and [Cu2(H4MHTS)(OAc)4(H2O)2].2H2O, respectively.IR data showed that H4MHTS ligand acts as either dibasic O2N2O2 hexadentate in Co2+ and Ni2+ complexes or neutral O2N2S2 hexadentate. An octahedral environment was suggested for all complexes according to spectral and magnetic susceptibility. The low magnetic moment value of Co2+ complex confirms strong M-M interaction μeff. (3.69). DFT method we used to confirm the geometries of title compounds and evaluate other energetic parameters such as HOMO, LUMO, hardness, softness and electronegativity. Also, the thermal stability was examined by TG and DTG and the associated thermodynamic parameters of activation were determined using Coats-Redfern and Horowitz-Metzger methods. The data indicated that the thermal degradation process is slow, endothermic and non-spontaneous one. The in vitro cytotoxicity against cell lines, Mammary gland breast cancer (MCF-7) using doxorubicin as standard was examined revealing the potent activity of the thiosemicarbazide.