New Metal Complexes with Azo-Schiff Base Ligand Synthesis, Characterisation and Biological Activity

Abstract

Synthesis and characterization of a new azo-Schiff base ligand (1-(4-((E)-(3-hydroxy-4-((E)-((4-nitrophenyl)imino)methyl)naphthalen-2-yl)diazenyl)phenyl)ethan-1-one) (HL), derived from ((E)-3-((4-acetylphenyl)diazenyl)-2-hydroxy-1-naphthaldehyde)) with 4-nitroaniline in a one to one molar ratio. Subsequently, the interaction of HL with various metal ions (CoII, NiII and CuII) in the ratio of one ligand to one metal, produced monomeric coordination connections. These compounds have been fully characterised using analytical methods and spectroscopic techniques, involve elemental microanalysis,1H and 13C-nuclear magnetic resonance, Fourier transform infrared spectroscopy, electronic and mass spectroscopy, as well as magnetic susceptibility and Conductivity measurements. The analytical data verified the formation of coordination compounds exhibiting four and six-coordinate geometries. The antibacterial evaluation for the ligand and its metal complexes against bacterial strains and fungus species showed a significant enhancement in the effectiveness of the antimicrobial ligand when forming complexes with metal ions. In addition, the study evaluated the antibacterial activity of synthesised compounds with a number of bacteria and fungi. The complex formation significantly enhanced the antibacterial efficacy of the ligand.