The synthesis, characterization, electrochemical character, catalytic and antimicrobial activity of novel, azo-containing Schiff bases and their metal complexes

Three novel Schiff base ligands containing the azo group, 2-((E)-(4-((E)-phenyldiazenyl)phenylimino)methyl)phenol, 3-((E)-(4-((E)-phenyldiazenyl)phenylimino)methyl)benzene-1,2-diol and 4-((E)(4-((E)-phenyldiazenyl)phenylimino)methyl)benzene-1,2,3-triol, were synthesized from the reaction of p-aminoazobenzene with salicylaldehyde, 2,4-dihydroxybenzaldehyde and 2,3,4-trihydroxybenzaldehyde, respectively. The mononuclear Co(II) and Cu(II) complexes of the Schiff base ligands were prepared and characterized using elemental analyses, IR, UV-visible spectroscopy, magnetic susceptibility and conductance measurements: H-1 NMR and mass spectra of the ligands were also recorded. The Co(II) and Cu(II) metal complexes are formed by the coordination of the N and 0 atoms of the ligands. The electrochemical properties of the metal complexes were investigated at 100 mVs(-1) scan rate in DMSO; the oxidative C-C coupling properties of the Co(II) and Cu(II) complexes were investigated on the sterically hindered 2,6-di-tert-butylphenol (DTBP). In addition, the Schiff base ligands and their complexes were evaluated for both their in vitro antibacterial activity using the disc diffusion method. (c) 2008 Elsevier Ltd. All rights reserved.