Synthesis, Crystal Structure, DNA‐binding Properties and Antioxidant Activity of a Copper(II) Complex with Naphthalimide Schiff Base

The Schiff N‐allylamine‐4‐(ethylenediamine‐5‐methylsalicylidene)‐1,8‐naphthalimide (H2L) and its copper(II) complex, [Cu(HL)2]·0.5DMF, were synthesized and characterized. The crystal structure of the CuII complex reveals a slightly distorted square‐planar arrangement provided by two N and O donors from two deprotonated ligands. In addition, the DNA‐binding properties of the ligand and CuII complex were investigated by fluorescence spectra, electronic absorption, and viscosity measurements. The experimental studies of the DNA‐binding properties indicated that the ligand and CuII complex reacted with DNA via intercalation binding mode, and binding affinity for DNA takes the order: ligand > CuII complex. The antioxidant assay in vitro suggested that both exhibited potential intensely antioxidant properties, and the ligand is more effective than its CuII complex.