Microwave Assisted Synthesis and Characterization of Novel Schiff Base Ligand and Biological Activity of Transition Metal Complexes Derived From 4-Cyano-2-Fluoro Benzohydrazide with Indole-3-Carbaldehyde

Abstract

A new series of novel Schiff base ligand (E)-N'-((1H-indol-3-yl) methylene)-4-cyano-2-fluorobenzohydrazide, was synthesized by using microwave assisted method of 4-cyano-2-fluorobenzohydrazide with indole-3-carbaldehyde. Transition metal complexes of Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) were prepared and characterized using elemental analysis, FT-IR, UV-Vis spectroscopy, 1H NMR, Mass Spectrometry, and Thermal Analysis. The results confirmed bidentate coordination of the ligand through azomethine nitrogen and carbonyl oxygen atoms. The complexes exhibited octahedral geometry for Mn (II), Co (II), Ni (II), and Cu (II), while Zn (II) formed an octahedral complex. The ligand and its metal complexes were evaluated for antimicrobial activity against Escherichia coli, Staphylococcus aureus, S.Typhi. The complexes demonstrated enhanced biological activity compared to the free ligand, with Cu (II) complex showing the highest antimicrobial effect. These findings suggest the potential of Schiff base-metal complexes in pharmaceutical applications.