DNA-binding, cleavage, antibacterial and in vitro anticancer activity of copper(II) mixed ligand complexes of 2-(((6-chloro-1H-benzo[d]imidazol-2-yl)methyl)amino)aceticacid and polypyridyl ligands

A tridentate ligand(A), 2-(((6-chloro-1H-benzo[d]imidazol-2-yl)methyl)amino) aceticacid (Cl-BIGH) was synthesised by the Phillips condensation of 4-chlorobenzene-1,2-diamine and iminodiaceticacid in 1:2 molar ratio. Its Cu(II) mixed ligand complexes[Cu(II)-A-L] were obtained by involving other co-ligands(L): 2,2΄-bipyridine(L1), 4,4΄-dimethyl-2,2΄-bipyridyl(L2), 5,5΄-dimethyl-2,2΄-bipyridyl(L3) and 1,10 phenanthroline(L4). The complexes were characterized by elemental analysis, thermal analysis, molar conductance, magnetic moment measurements, X-ray diffraction, FTIR, UV–Visible, ESR spectroscopy, mass spectrometry and cyclic voltammetry. From the spectral and analytical data, the ternary complexes [Cu(Cl-BIGH)(L1-4)]ClO4 were found to form in 1:1:1(Cu(II): Cl-BIGH: L) molar ratio. The geometry of the mixed-ligand complexes were found to be 5-coordinated square pyramidal or trigonal bipyramidal with polycrystalline natures. The DNA binding and cleaving abilities, antibacterial and the in vitro cytotoxicity of the complexes were explored. The molecular docking was used to predict the efficiency of binding of the metal complexes with COX- 2. Communicated by Ramaswamy H. Sarma