Nickel (II), Copper (II), and Zinc (II) Complexes of N-bis (4-methoxybenzyl) Dithiocarbamate: Synthesis, Characterization Studies, and Evaluation of Antitumor Activity

Abstract

Three new complexes with the general formula [M(L)2] (L=N-bis(4-methoxybenzyl) dithiocarbamate; M= Ni(II) 1, Cu(II) 2, and Zn(II) 3 ), have been synthesized, and characterized by elemental analysis, IR, UV–visible, 1H, 13C NMR and mass spectrometry. The magnetic behavior of nickel and copper complexes was measured and found to be diamagnetic and paramagnetic, respectively. Complex 3 crystallized in the monoclinic space group P21/c and possessed a centrosymmetric dimeric structure stabilized by weak C-H···S, C-H···π, and C-H…O intermolecular interactions. Electronic absorption spectral studies of the complexes show the absorption band in the range of 270-331 nm, which is due to intraligand charge transfer transitions. Complexes 1 and 2 also show transitions in the range of 325-475 nm due to ligand to metal charge transfer transition. The antitumor activities of the complexes have been screened, and the results obtained show that the metal complexes have significant antitumor activity against Dalton's lymphoma cells in a concentration-dependent manner, and the metal complexes were relatively tolerant to normal human cells with low or marginal toxicity against both lymphocytes and monocytes.