Synthesis, characterization, DNA-binding properties of the Ln(III) complexes with 6-hydroxy chromone-3-carbaldehyde-(4'-hydroxy) benzoyl hydrazone.

6-Hydroxy chromone-3-carbaldehyde-(4'-hydroxy) benzoyl hydrazone (L) and its Ln (III) complexes, [Ln = La, Nd, Eu and Tb] have been prepared and characterized on the basis of elemental analyses, molar conductivities, mass spectra, (1)H NMR, thermogravimetry/differential thermal analysis (TG-DTA), UV-vis spectra, fluorescence spectra and IR spectra. The formula of the complex is [Ln L.(NO(3))(2)].NO(3). Spectrometric titration, ethidium bromide displacement experiments and viscosity measurements indicate that Eu (III) complex bind with calf-thymus DNA, presumably via an intercalation mechanism. The intrinsic binding constant of Eu (III) with DNA was 2.48 x 10(5) M(-1) through fluorescence titration data.