Experimental and computational approaches of electronic properties and DNA binding of Cu(II) and Zn(II) complexes

Understanding the metallodrug-DNA interaction is of paramount importance for developing therapeutic agents, particularly cytotoxic drugs. This work reports the synthesis, characterization, and investigation of the electronic properties and DNA binding of the Cu(II) (complex 1 ) and Zn(II) (complex 2 ) complexes. The synthesized ligand and its metal complexes were carefully characterized using IR, 1 H NMR, 13 C NMR, HRMS, and molar conductance measurements. The morphology of the ligand and its complexes was analyzed using SEM. Density Functional Theory (DFT) calculations provided vital insights into the electronic properties of the ligand and complexes, detailing the HOMO-LUMO energy gaps. The location of HOMO and LUMO in the ligand and the complexes indicates a change in the electronic distribution upon complexation. TD-DFT analysis was carried out to gain further insight into the electronic properties of the ligand and its complexes 1 and 2 . The interaction of complexes 1 and 2 with CT-DNA was investigated using absorption and emission spectroscopy, as well as viscometry. The binding constant ( K b ) values of 2.0 × 10⁵ and 1.0 × 10 5 M −1 for complexes 1 and 2 , respectively, indicate that both complexes have significant binding propensity for DNA. Furthermore, molecular docking analyses were utilized to predict the binding modes and affinities of these complexes with CT-DNA. This integrated experimental and computational investigation offers valuable insights into the development of potential metal-based therapeutic compounds.