Synthesis, characterization and crystal structures of copper(II) and nickel(II) complexes of propargyl arm containing N_2O_2 ligands: Antimicrobial activity and DNA binding

摘要

Ni(II) and Cu(II) complexes of propargyl arm containing N_2O_2 Schiff base donor ligands (L~1-L3) were prepared and characterised by elemental analysis, IR, NMR and UV-Vis spectroscopy. The crystal structures of CuL3 and NiL3 were determined by single crystal X-ray diffraction measurements. The coordination geometry around the copper and nickel centres is square planar, with the plane formed by the N_2O_2 donors of the Schiff base ligand. The crystal packing is stabilized by C-H?O intermolecular hydrogen bonding and further influenced by C-H?π interactions. The electrochemical behaviour of the synthesized copper complexes was studied and the results obtained evidenced their irreversible oxidation. Antibacterial activity was assayed against selective Gram(+ve) and Gram(-ve) microorganisms. The DNA binding behaviour of the complexes was investigated using absorption and fluorescence titration measurements.