Synthesis, characterization, and DNA-binding of Ln(III) complexes with 2-hydroxybenzylidene-2-phenylquinoline-4-carbonylhydrazone

2-Hydroxybenzylidene-2-phenylquinoline-4-carbonylhydrazone (H2L) and five Ln(III) complexes, [Ln(H2L)(NO3)2]NO3 [Ln = La (1), Pr (2), Sm (3), Eu (4), and Tb (5)], have been synthesized and characterized by 1H NMR, elemental analysis, conductivity measurements, mass spectra, IR spectra, and UV spectra. The interaction of these complexes with calf thymus DNA was investigated by UV absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Results suggest that these complexes bind to DNA via groove binding.