Synthesis and characterization of a novel Cu(II) complex bound to a naphthalene-core Schiff base, and studies of its interaction with DNA

This abstract describes the synthesis and characterization of a novel Cu(II) complex derived from a Schiff base formed by 2-hydroxy-1-naphthaldehyde and 2-(aminoethyl)pyridine. EPR characterization revealed a square-planar geometry and a dx²−y² ground state, imposed by the mixed {O, N, N, Cl} donor set. UV-Vis spectra showed intraligand π→π* transitions and ligand-to-metal charge transfer (LMCT) bands from the phenol and imine moieties to the metal center. FTIR, Raman, conductometry, and cyclic voltammetry were also used to characterize the complex. The interaction with salmon sperm DNA, evaluated by electronic absorption spectroscopy in Tris buffer (pH 7.2, 25% DMSO) at 25 °C, showed significant changes in the band at 380 nm, confirming the interaction between the complex and the biomolecule. These findings point to the complex's potential for biomedical applications, particularly in the development of new copper-based antitumor agents.