Synthesis, characterization and antimicrobial activities of Schiff base complexes derived from Salicylaldehyde and amino acid (isoleucine)

Complexes of Fe(II), Co(II), Cu(II), and Zn(II) with a Schiff base derived from salicylaldehyde and isoleucine were successfully synthesized. All complexes were distinctly colored and were characterized by molar conductance, magnetic susceptibility, infrared and UV spectroscopy. Infrared spectroscopy shows the Schiff base ligand is coordinated to the central metal ion in a tridentate manner through the N-atom of the azomethine and two oxygen of the phenol and carboxylate. All complexes contain two ligands molecules per metal ion (ML2). An octahedral geometry is proposed for the metal complexes. Antimicrobial study of the complexes was undertaken against five pathogenic bacteria strains and two fungi, mucus species and Aspergillus fumigates. The result reveal that most of the complexes and particularly Co (II) and Zn (II) have a much enhanced activity against Staphyllococcus aureus, Escherichia coli and Klebsiella pneumoniae.