Synthesis, spectral characterization, and DNA binding studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff base 2-((1H-1,2,4-triazol-3-ylimino)methyl)-5-methoxyphenol

A Schiff base ligand HL has been synthesized by the condensation of an equimolar amount of 2-hydroxy-4-methoxybenzaldehyde and 3-amino-1,2,4-triazole and characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and ESI-mass spectrometry. The metal complexes 1-4 have been synthesized by the reaction of ligand with Co(II), Ni(II), Cu(II) and Zn(II) chlorides in ethanol in the molar ratio 1:1. All the metal complexes 1-4 were characterized by elemental analysis, molar conductance, electronic spectra, IR, and EPR spectra. TGA has been done to check the stability of the synthesized Schiff base ligand HL and its metal complexes 1-4. Spectral data reveals that the ligand HL acts as uninegative tridentate for metal complexes. The geometries of synthesized ligand and its metal complexes were optimized by using Gaussian 09 W program. On the basis of spectral characterization, octahedral geometry has been allocated for Co(II), tetrahedral for Ni(II), tetragonal for Cu(II) and tetrahedral for Zn(II) complexes. The DNA binding studies of metal complex have been investigated by UV absorbance, fluorescence and CD spectrometry. UV absorbance binding studies show that metal complex 1-3 could bind to ctDNA significantly and the results obtained were consistent with the fluorescence and CD spectra. (C) 2018 Elsevier B.V. All rights reserved.