Mechanochemical Synthesis and Potentiation of the Antimicrobial Activity of 4-[3-(4-methoxyphenyl)-allylideneamino]-1,5-dimethyl-2-phenylpyrazol-3-one by Metal Chelation

A Schiff base ligand, 4-[3-(4-methoxyphenyl)-allylideneamino]-1,5-dimethyl-2-phenylpyrazol-3-one has been synthesized by the condensation of Methoxycinnamaldehyde and 4-aminoantipyrine. Its divalent metal complexes of Co, Ni, and Cu were also synthesized using the mechanochemical solvent-free method. The ligand and the complexes were characterized by FTIR, UV/visible, 1H NMR, 13C NMR, and GC-MS. The ligand behaved as a bidentate donor by using its carbonyl and azomethine N as binding sites for the metals. The ligand showed low activity against some microbes but the complexes were remarkably active against the fungi species.