Synthesis, crystal structure and characterization of new biologically active Cu(II) complexes with ligand derived from N-substituted sulfonamide

Abstract

A new N-sulfonamide ligand (HL1 = N-(5-(4-methoxyphenyl)-[1,3,4]–thiadiazole–2-yl)-toluenesulfonamide) and two Cu(II) complexes, [Cu(L1)2(py)2] (C1) and [Cu(L2)2(py)2(H2O)] (C2) (HL2 = N-(5-(4-methylphenyl)-[1,3,4]–thiadiazole–2-yl)-benzenesulfonamide) were synthesized. The X-ray crystal structures of the complexes were determined. In the complex C1, the Cu(II) ion is four-coordinated, forming a CuN4 chromophore and in the complex C2, the Cu(II) ion is five-coordinated, forming a CuN4O chromophore. The ligand acts as monodentate, coordinating the Cu(II) ion through a single Nthiadiazole atom. The molecules from the reaction medium (pyridine and water) are also involved in the coordination of the Cu(II) ion. The complexes C1 and C2 are square-planar and a slightly distorted square pyramidal, respectively. The compounds were characterized by FT-IR, electronic, EPR spectroscopic and magnetic methods. The nuclease binding activity studies of the synthesized complexes confirm their capacity to cleave the DNA molecule. The cytotoxicity studies were carried out on melanoma cell line WM35 which confirm that both compounds inhibit the growth of these cells. They have a higher activity compared to a platinum drug, carboplatin. A new N-sulfonamide ligand (HL1= N-(5-(4-methoxyphenyl)-[1,3,4]–thiadiazole–2-yl)-toluenesulfonamide) and two Cu(II) complexes, [Cu(L1) 2 (py) 2 ] and [Cu(L2) 2 (py) 2 (H 2 O)] (HL2= N-(5-(4-methylphenyl)-[1,3,4]–thiadiazole–2-yl)-benzenesulfonamide) were synthesized.The X-ray crystal structures of the complexes have been determined. Interaction of complexes with the DNA molecule and cytotoxicity studies were carried out.