Synthesis, structure characterization and antitumor activities of copper and cobalt thiocyanate complexes with 3-acetlpyridine ligand

Complexes of [Cu(SCN)2(3-Acpy)2], (1) and [Co(SCN)2(H2O)2(3-Acpy)2], (2) were synthesized at ambient temperature by adding an aqueous solution of copper(II) or cobalt(II) chloride to H2O/CH3CN solution of 3-acetlpyridine (3-Acpy) and potassium thiocyanate. Elemental analysis, FT-IR and UV–vis spectra were used to comprehensively characterize complexes 1 and 2. Single crystal X-ray diffraction was used to analyze the crystal structure of complexes 1 and 2. In complex 1, the copper is bonded to two 3-Acpy ligands and two thiocyanates groups in trans mode giving square planer geometry. While, in complex 2, the cobalt ion is coordinated to two water molecules, two 3-Acpy ligands and two thiocyanates ions in trans mode giving an octahedral structure. Through hydrogen bonding, the discrete units of complexes 1 and 2 extend to form a 3D supramolecular network. Additionally, the luminescence spectra of complexes 1 and 2 were investigated. Complexes 1 and 2 were evaluated to determine whether they were able to inhibit the growth of liver cancer (HepG2 cells) and breast cancer (MCF-7 cells). Complex 1 exhibits lower IC50 values than complex 2 against both of the two human cell lines. In HepG2 cells treated with complexes 1 and 2 at dosages roughly half of the IC50, apoptosis of complexes 1 and 2 is triggered by 18% and 22%, respectively. It was found that copper complex 1 has a greater cytotoxic effect on MCF-7 and influences on late apoptosis of HepG2.