Synthesis, characterisation and antibacterial study of copper(ii) complexes of new benzylacetone-benzoylhydrazone and its <i>para</i>-nitro and <i>para</i>-hydroxy substituted analogues

Abstract

Three new ligands viz, benzylacetone-enzoylhydrazone [babh (L¹)], para-hydroxy-benzylacetone-
benzoylhydrazone [p-OH-babh (L² )] and para-nitrobenzylacetone-benzoylhydrazone [p-NO₂ -babh (L³ )], were synthesised by condensation of hydrazides with benzylacetone. The ligands were each reacted with copper(II) salts (chloride, nitrate, acetate and sulphate) to form complexes with the general formulae ML₂X₂ (X = Cl , NO₃ , AcO^- and SO₄ ). The compounds were characterised using ¹H NMR, Infrared and UV-Visible spectroscopy, as 4 well as CHN elemental analyser and magnetic susceptibility measurements. Antibacterial activity of the ligands and synthesised complexes were investigated using the agar diffusion method against two Gram-positive (Staphylococcus aureus NCTC 6571 and Bacillus cereus ATCC 11778) and three Gram- negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145, Klebsiella pneumonia ATCC 13048) bacterial strains. However, the observed antimicrobial strength of the synthesized compounds was rather low.