Synthesis , characterization and antibacterial activity of copper ( ii ) and nickel ( ii ) complexes with 3 , 10 - dialkyl - 1 , 3 , 5 , 8 , 10 , 12 hexaazacyclotetradecane ligand

14-membered hexaazamacrocyclic complexes were synthesized by the condensation reaction method of ethylenediamine, formaldehyde, and either butylamine or hexylamine using metal salt as Cu(II) and Ni(II) in a 2 : 4 : 2 : 1 mole ratio, respectively. The chemical formula of complexes was [CuL1](ClO4)2 (1), [NiL1](ClO4)2 (2), [CuL2](ClO4)2 (3), and [NiL2](ClO4)2 (4), where L1 = 3,10-dibutyl-1,3,5,8,10,12hexaazacyclotetradecane and L2 = 3,10-dihexyl-1,3,5,8,10,12-hexaazacyclotetradecane). All complexes were characterized by Elemental analysis (% CHN), Fourier-Transform Infrared spectroscopy (FT-IR), UV-Visible spectroscopy (UV-Vis), and Liquid Chromatography-mass spectroscopy (LC-MS) techniques to confirm the complex structures. The results showed that the copper(II) and nickel(II) complexes were square-planar geometry, with four secondary amine nitrogen atoms of the macrocyclic ligand occupying in the equatorial plane and two oxygen atoms from perchlorate ions to be a weak bond as coordinated with copper(II) and nickel(II) ions in the axial position. These complexes were screened against different bacteria, Staphylococcos aureus (S. aureus) and Escherichia coli (E. coli), and were compared with tetracycline as the standard drug by the agar diffusion method. The antibacterial activities of Cu(II) and Ni(II) complexes with hexaazamacrocyclic ligand showed good effective antibacterial activities but were lower than standard antibacterial drugs; the inhibitory effects of complexes were found to be against the microorganisms tested.