Modern Method for the Preparation of Some Metal Oxides in the Form of Nanometric Feature using Schiff Base Complexes as Precursors: Synthesis, Characterization and Antibacterial Properties

Metal complexes, ML2X2, where M is Mn(II), Co(II) or Cu(II), X = (NO3 –or Cl–), and L is the Schiff base formed by condensation of 2-thiophenecarboxaldehyde with phenyl hydrazine have been prepared and characterized by elemental analysis, magnetic and spectroscopic measurements (infrared, Raman, X-ray powder diffraction and scanning electron microscopy). Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal-ligand). Infrared spectra of the complexes agree with the coordination to the central metal atom through the nitrogen of the phenyl hydrazine (–Ph–NH-) group and the sulfur atom of the thiophene ring. Magnetic susceptibility data coupled with electronic spectra suggest a distorted octahedral structure for all Schiff base complexes. The Schiff base and its metal chelates have been screened for their in vitro antibacterial activity against four bacteria, gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial activity than the free Schiff-base chelate.