Synthesis, Characterization and Antibacterial Activity of Mixed Ligands of Schiff Base and It’s Metal(II) Complexes Derived from Ampicilin, 3-Aminophenol and Benzaldehyde

Abstract

Schiff base ligands were synthesis via a condensation of the ligands in methanol in 1:1:1 molar ratio reactions. The transition metal(II) complexes were formed by the reaction of Co, Cu, Mn, Fe with the Schiff base and ampicillin and they were characterized via FTIR, electronic spectra, melting points, solubility and molar conductance. The <i>invitro </i>antibacterial activities of the complexes were tested using four bacterial strains; gramnegative; (<i>Escherichiacoli, salmonellatyphi</i>) and grampositive; (<i>staphylococcus pyogenes and staphylococcus aureus</i>). The complexes were formed in good yield and they have various shades of colors and sharp melting points. The IR spectrum of the HL (Table4) displays a new at (1651) cm^-1which is due to υ(HC=N) group of the azomethine stretching vibrations of the ligand, on complexation these band has been shifted to lower frequencies (1651), (1621), (1651), and (1627)cm^-1for complexes [Co(Ampi)(3AMPB)Cl], [Cu(Ampi)(3AMPB)], [Mn(Ampi)(3AMP)Cl] and [Fe(Ampi)(3AMPB)] respectively. The overlap band at (1688)cm^-1stretching vibration is due to υ(C=O) for β-Lactam group, these band has been shifted to lower frequency at (1370-1425)cm^-1for complexes showing that the coordination is through the Oxygen atom of β-Lactam group. The band sat (525), (526), (524) and (526)cm^-1were assigned to υ(M–O) for compounds of Co, Cu, Mn, Fe, indicating that to the carbocyclic oxygen, and oxygen of β-Lactam group of the ligand are involved in coordination with metalions. The bands at (659), (669), (660), and (698)cm^-1were assigned to υ(M–N) for compounds Co, Cu, Mn, Fe respectively, indicating that the nitrogen is involved in coordination with metal ions. The electronic spectral data of the complexes suggest an Octahedral and tetrahedral geometry for all the complexes. The molarconductivity indicates that the synthesized complexes are all non-electrolytes and soluble in protic solvent such as methanol and ethanol. The <i>invitro </i>antibacterial screening of Schiff base and its metal complexes showed that they are potential antibacterial agents against the tested microorganisms