Mixed phenoxo and azido bridged dinuclear nickel(II) and copper(II) compounds with N,N,O-donor schiff bases: Synthesis, structure, DNA binding, DFT and molecular docking study

Two dinuclear complexes, mu-phenoxo, mu(1,1)-azido bridged [Ni-2(L)(2)(mu(1,1)-N-3)(N-3)(CH3OH)] (1) and mu-phenoxo, mu(1,1)-azido bridged [Cu-2(L)(2)(mu(1,1)-N-3)(N-3)] (2) bearing HL as a blocking co-ligand produced by the 1:1 condensation of N-methyl 1,3 propanediamine with o-vanillin have been synthesized and successfully characterized by elemental analyses, IR and electronic spectroscopy, single-crystal X-ray diffraction for 1 and DFT optimization for 2. X-ray crystal structure discloses that the asymmetric unit of 1 consists of two nickel(II) ions exhibiting a six-coordinate octahedral coordination with mu-phenoxo, mu(1,1)-azido bridging dimeric structure. The DFT optimization of 2 reveals the five-coordinate distorted square pyramidal geometry around two copper(II) ions with mu-phenoxo, mu(1,1)-azido bridging dimeric structure. Complexes 1 and 2 are investigated for their binding affinity towards CT-DNA in aqueous medium containing DMSO (10%) at pH similar to 7.4 using UV-Vis and fluorescence spectroscopic techniques. Docking study has been further done to support DNA binding property. DFT calculation has been performed to support structural and electronic parameters of the complexes.