A Novel Macrocyclic Binuclear Copper (II) Complex: Structural Clarification, Biomolecular Interactions, and Nucleic Acid Cleavage Activity

A novel cationic binuclear copper (II) complex, Cu 2 L(H 2 O) 2 (ClO 4 ) 2 , has been synthesized, and its structure is described. It is formed from a symmetrical macrocyclic Schiff‐base ligand. The distorted square‐pyramidal geometries adopted by both Cu (II) centers and their bridging phenoxide oxygen atoms are confirmed by single‐crystal X‐ray diffraction. Molecular docking experiments, viscosity tests, circular dichroism, fluorescence spectroscopy, and UV–Vis absorption were used to examine the complex’s DNA‐ and protein‐binding capabilities. Both hydrodynamic and spectroscopic results show a strong static quenching interaction with bovine serum albumin and an intercalative binding mode toward calf thymus DNA. Effective oxidative cleavage of the pBR322 plasmid DNA is demonstrated by agarose gel electrophoresis, indicating the involvement of reactive oxygen species. Additionally, both Gram‐positive and Gram‐negative pathogens are susceptible to the complex’s strong antibacterial action. Stable binding interactions with DNA and DNA gyrase are further supported by docking experiments. These results demonstrate the binuclear Cu (II) complex’s biological potential for use in bioinorganic and pharmaceutical chemistry.