International Research Journal of Pure and Applied Chemistry

In this study, benzylacetone-benzoylhydrazone ligand (BABH) and its heteroleptic metal(II) complexes [Co(II), Ni(II) and Cu(II)] with 2, 2´-bipyridine, 1, 10-phenanthroline, and ethylenediamine (N-N donors) were synthesized. The compounds were analysed with spectroscopic techniques (Infrared; IR, Ultraviolet-Visible; UV-Vis, ¹H NMR), percentage metal analysis, magnetic moment measurement and conductivity measurements. The Calf-thymus-DNA interaction with the complexes was examined using electronic absorption spectroscopy. The ¹H NMR indicated the formation of BABH. Infrared spectra indicated that BABH coordinated to the metal ions in enol form via the deprotonated carbonyl group and the azomethine group, while N-N donor ligands bound through the pyridinic nitrogen atoms. The UV-Vis spectra of the compounds had intra-ligand transitions due to π-π* and n-π* in the UV region, and d-d transitions typical for Cu(II), Ni(II) and Co(II) ions in the visible region. Molar conductivity of the complexes in DMF indicated a 1:1 electrolyte, except [Cu(BABH)(phen)(H₂O)Cl] with a value of 50.20 (Ω^-1cm²mol^-1) which suggested a non-electrolyte. The percentage metal analysis revealed a stoichiometry ratio of 1:1:1 (Metal: Ligand: N,N-donor), except for the bipyridine complexes that had a probable 1:1:2 ratio (Metal: Ligand: N,N-donor). The magnetic moment for Cu(II) complexes ranges from 1.80 - 2.34 B.M indicating octahedral geometry, while Ni(II) complexes had values ranging from 2.88 to 3.28 B.M indicating octahedral geometry, except [Ni(BABH)(en)]Cl.H₂O that had a value of 0.89 B.M. which indicated a square palanar nickel(II) complex. Co(II) complexes had values for octahedral geometry (3.77 - 4.81 B.M), except [Co(BABH)(en)]Cl.H₂O that had a 1.96 B.M, revealing a square planar geometry. Interactions of the synthesized compounds with CT-DNA represents an intercalative binding mode, with [Co(BABH)(bpy)₂]Cl.H₂O having the best binding strength of 6.74 x 10⁴ M^-1. The results have shown that the synthesised metal(II) complexes of Benzylacetone-benzoylhydrazone mixed with N,N-donors has potential ability to disrupt the growth of tumour cells due to their good binding strength.