Synthesis, characterisation and antimicrobial studies of mixed nickel (II) and copper (II) complexes of aroylhydrazones with 2, 21 - bipyridine and 1, 10-phenanthroline

Abstract

Herein, we report the synthesis of 2-anisaldehyde-benzoylhydrazone (L₁), vanillin-benzoylhydrazone (L₂) and mixed Ni(II) and Cu(II) complexes of L₁ and L₂ with 2, 2¹ -bipyridine and 1, 10-phenanthroline (N-N bases). The resulting compounds were characterized by ¹H NMR, IR, UV-VIS, Solubility studies, percentage Metal analysis, Conductivity measurements, and Magnetic Moment measurements. ¹H NMR spectra indicated the formation of the ligands. IR Spectra showed that the ligands coordinated in enol form through the deprotonated carbonyl bond (C=O) and the azomethine (C=N). The (N-N) bases similarly coordinated through the (C=N). The magnetic moment values for the Cu(II) complexes ranges from 2.14 to 2.36 B.M Magnetic moment values ranging from 2.78 to 3.11 B.M were found for the complexes of Nickel except [Ni(L₂)(bpy)]Cl and [Ni(L₂)phen]Cl that had moment of 0.49 and 0.75 B.M respectively. Conductance values indicated a 1:1 electrolyte for the complexes. The antimicrobial activities of the ligands and their mixed ligand complexes were screened using Agar diffusion method. It was found that the mixed metal complexes have higher antimicrobial activity than the free ligands.

Keywords: Benzylhydrazone, Spectroscopy, Magnetic moment, Geometry, Zone of inhibition