SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES OF IRON(II) AND COBALT(II) COMPLEXES OF A SCHIFF BASE DERIVED FROM 2-ACETYLTHIOPHENE WITH 4-PHENYLTHIOSEMICARBAZIDE

Abstract

Fe(II) and Co(II) complexes of Schiff base; 2-acetylthiophene-4-phenylthiosemicarbazide (AT-PTSC) which is derived from condensation of 2-acetylthiophene with 4-phenylthiosemicarbazide in (1:1 molar ratio) ethanol, have been synthesized. The Schiff base and the complexes were characterized on the basis of melting point/decomposition temperature, solubility, magnetic susceptibility, infrared spectra, molar conductance measurements, elemental and gravimetric analysis. The complexes showed moderate values of decomposition temperatures The Schiff base and the complexes were soluble in some common organic solvents. Infrared spectral data of the Schiff base and their complexes, indicating coordination of the Schiff bases to the metal(II) ion via azomethine nitrogen. The effective magnetic moment of the complexes suggested an octahedral geometry. The molar conductance values of the complexes show that the complexes were electrolytes. The results of the elemental analysis were in good agreement with the calculated values, suggesting a 1:2 (metal-ligand) ratio. Antimicrobial screenings of the ligands and their complexes were conducted against against gram-positive (Staphylococcus aureus,) and two gram-negative (Salmonella typhii, and Escherichia coli) bacteria specie. Also three fungi mainly (Candida albicans, Mucus indicus and Aspergillus flavus) were tested. The results showed that both the ligands and the complexes are active against the specie used.  Keywords: Ligand, Schiff base, 4-phenylthiosemicarbazide, 2-acetylthiophene, molar conductivity, magnetic susceptibility, elemental analysis.