Synthesis, characterization and nucleic acid binding studies of mononuclear copper(II) complexes derived from azo containing O, O donor ligands

Abstract

Azo linked salicyldehyde and a new 2-hydroxy acetophenone based ligands (HL1 and HL2) with their copper(II) complexes [Cu(L1)2] (1) and [Cu(L2)2] (2) were synthesized and characterized by spectroscopic methods such as 1H, 13C NMR, UV–Vis spectroscopy and elemental analyses. Calculation based on Density Functional Theory (DFT), have been performed to obtain optimized structures. Binding studies of these copper (II) complexes with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) were analyzed by absorption spectra, emission spectra and Viscosity studies and Molecular Docking techniques. The absorption spectral study indicated that the copper(II) complexes of 1 and 2 had intrinsic binding constants with DNA or RNA in the range of 7.6 ± 0.2 × 103 M−1 or 6.5 ± 0.3 × 103M−1 and 5.7 ± 0.4 × 104 M−1 or 1.8 ± 0.5 × 103 M−1 respectively. The synthesized compounds and nucleic acids were simulated by molecular docking to explore more details mode of interaction of the complexes and their orientations in the active site of the receptor.