Synthesis and crystal structures of cobalt(II), cadmium(II), and zinc(II) complexes of 4-nitro phenylcyanamide: enhancing the biological properties through bound to human serum albumin.

Metal complexes of the type [Co(phen)2(4-NO2pcyd)2].CH3OH, 1, [Zn(phen)2(4-NO2pcyd)2].CH3OH, 2, [Cd(phen)2(4-NO2pcyd)2], and 3, (phen = 1,10-phenanthroline, 4-NO2pcyd = 4-nitro phenylcyanamide) have been studied. The synthesis, characterization, and the biological activities of complexes 1-3 have been investigated. The geometries of complexes 1-3 were confirmed by single-crystal X-ray crystallography. The interactions of complexes 1-3 with human serum albumin (HSA) were studied using fluorescence and circular dichroism spectroscopy. The thermodynamic studies have showed the reaction for the binding of complexes 1-3 with HSA is hydrophobic (ΔH0 ˂ 0 and ΔS0 > 0). The in vitro cytotoxic potential of complexes 1-3 and their complexes with HSA were examined. The complexes 1-3 with HSA enhance about 3-fold cytotoxicity in cancer cells lines.