SYNTHESIS, CHARACTERIZATION AND INVITRO-ANTI-MICROBIAL ACTIVITIES OF 3- NITRO –N- (3-NITROBENZYLIDINE) ANILINE SCHIFF BASE COMPLEXES OF COBALT (II) AND CU (II)

Abstract

Background: Schiff base derived from an equimolar amount of 3-nitrobenzaldehyde with P-nitro aniline was synthesized.

Methodology: A solution of 1.02 ml of 3-nitrobenzaldehyde [0.01m] in 10ml of ethanol, and 1.38gm 0f 4-nitroaniline [0.01m] in 10ml ethanol was added in a beaker. a few drops of glacial acetic acid were added to adjust the pH of the solution. The reaction mixture was stirred in 5 hours; after stirring cool water was added, the obtained precipitate was collected by filtration. It was well dried and recrystallized from ethanol and dried at room temperature, the yellow product of Schiff base ligand was obtained after re-crystallization. The Schiff base was subsequently reacted with Cobalt (II) chloride and Copper (II) chloride to form the metal complexes. The compounds were characterized using FTIR, UV-visible, melting point/decomposition and solubility test.

Results: The solubility test of the compounds showed that they are soluble in most organic solvents and the melting point of the Schiff base ligand was found to be 147.8 oC and the decomposition temperature of the Cobalt (II) and Copper (II) were found to be 158.8oC and 157.9oC for the Cobalt (II) and Copper (II) complexes respectively. The UV and the IR spectroscopy confirmed the formation of complex. The antimicrobial studies of the synthesized ligands and their Cobalt (II) and Copper (II) metal complexes were carried out against Aspergillus, Gram positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

Conclusion: The results indicated that the metal complexes were more active than the ligand but less active compared to standard drugs (ciprofloxacin and fluconazole).