Copper(II) complexes with a (N,O)-donor Schiff base ligand : Syntheses, crystal structure, DNA interaction study and molecular docking

Syntheses and structural characterization of two copper(II) complexes, [Cu(L)] (1) and [Cu-2(L)(NCS)(H2O)] (2) [L = N,N'-bis(salicyaldehydene)-1,3-diaminopropan-2-ol] have been reported. The structure of 1 has been determined by single crystal X-ray diffraction study while spectroscopic characterization has been performed to determine the structure for 2. Complex 1 crystallizes in P-1 space group with a = 7.7816(10) angstrom, b = 9.5871(12) angstrom and c = 10.5879 angstrom. Electron paramagnetic resonance (EPR) spectra of the copper(II) complexes 1 and 2 show a broad signal at g = 2.07 and 2.11. The binding property of the complexes with calf thymus DNA (CT-DNA) has been investigated using absorption and emission studies, viscosity experiments and cyclic voltammetry studies. Spectroscopic and hydrodynamic investigations revealed an intercalative mode of binding of 1 and 2 with CT-DNA. The copper(II) complexes have been found to induce effective cleavage of the supercoiled pBR 322 DNA. Molecular docking reveals that the complex 1 interacts with CT-DNA through substantial hydrogen bonding.