Synthesis and Spectroscopic Characterization of Iron Complexes with Bidentate Schiff’s Base Ligands Derived from 2-Benzoylpyridine, 2-Benzoylthiophene and Thiosemicarbazone, Semicarbazone, and their Biological Activity


Meenakshi Gupta, Bhupendra Kumar Sarma, S.Chandra, Sangeeta Gupta, Sanjay Singhal

Abstract

Objective: To synthesise and characterize Schiff’s base ligands and their iron complexes and study their antimicrobial activity.

Material and method: The Schiff’s base ligands and their complexes were prepared by reflux method for 7-8 hrs. In each case pH was adjusted as per the requirement. Ethyl alcohol was used as solvent. Ligand 1 was highly soluble in water and its complexes were prepared in water. Round bottom flask (100 ml), condenser and heating mental were used as apparatus.

Result: The complexes of Fe(III) and Fe(II) having the general composition FeL2X3 (where L = 2-benzoylpyridine thiosemicarbazone(L1), 2-benzoylpyridine semicarbazone (L2) and 2-benzoylthiophene semicarbazone (L3) and X = Cl-, NO3-, ½SO42-)  have been synthesised and were characterised by IR, elemental analysis, magnetic susceptibility, UV-Vis, conductivity, mass spectrometry and EPR spectral studies. On the basis of molar conductance value which was determined by using DMSO as solvent it can be concluded that all the complexes were 1:1 electrolytic in nature.   The value of magnetic moment indicates that all the complexes are of high spin type. On the basis of spectral studies an octahedral geometry has been proposed for Fe(II) and Fe(III) complexes. The complexes under study were investigated for antifungal (i.e. C. Krusei, C. Persapolis) and antibacterial (i.e. E. Coli and staphylococcus) activity.

Conclusion: The synthesised ligands were bidentate and complexes were found more active towards antimicrobial activity than ligands.     

Keywords: Mass, IR, NMR, EPR, semicarbazone, thiosemicarbazone