Syntheses, Characterisation and Antimicrobial Studies on Transition Metal Complexes of Methylphenyl-4-[phenyl (phenylhydrazono) Methyl]-3-pyrazolone

We aimed to synthesize the phenylhydrazone derivative of 4benzoyl-3-methyl-1-phenyl-5-pyrazolone which is a novel Schiff base. The ligand was synthesized in three stages. 3-methyl-1-phenyl-5-pyrazolone was synthesized as reported in the literature. (Ref. Vogel). This was benzoylated at the 4position to get 4benzoyl-3-methyl-1phenyl-5-pyrazolone (ref. Jesen’s procedure). This was condensed with phenylhydrazine to get the novel Schiff base. Though there are four potential ligating sites, only two of the ligating sites are involved in coordination. The ligand was characterised by elemental analysis and IR spectrum. Co(II), Ni(II) and Cu(II) complexes of the neutral bidentate chelating Schiff base ligand were synthesized using acetates, chlorides and nitrates of the metals. They were characterised by elemental analysis, conductance and magnetic susceptibility measurements, UV, VIS and IR spectra. The ligand exhibited tautomerism and the complexes were found to have octahedral geometry. The in vitro antifungal activity against Aspergillus niger of the ligand and the complexes were investigated using nutrient agar medium.