Innovative cyclic voltammetric analysis of copper(II)-ligand interactions: Urea and saccharin complexes for enhanced redox control

• Published in: Journal of molecular structure 2025-03, Vol.1325, p.140893, Article 140893
• Main Authors: Islam, Saiful, Asthana, Nidhi, Islam, Md. Jahidul, Harun-Ur-Rashid, Mohammad, Moral, Shamim, Khan, Azmat Ali, Fatima, Sabiha
• Format: Article
• Language: English
• Subjects: Cyclic voltammetry; Diffusion-controlled processes; Electrochemical behavior; Metal-ligand complexation; Saccharine; Urea
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2024.140893

•Cyclic voltammetry revealed the two-step reduction of Cu(II) to Cu(I) and Cu(0).•Ligand interactions with Cu(II) were evidenced by shifts in peak positions.•Saccharine and urea complexation with Cu(II) affected redox peak intensities.•Scan rate variations influenced the peak currents and potential separations.•Provides insights into metal-ligand complexation using electrochemical techniques. Cyclic voltammetry (CV) is a powerful tool for studying electrochemical processes. It provides qualitative insights into the presence of reaction intermediates and reversibility, as well as quantifies electron transfer processes, diffusion coefficients, and formal reduction potentials, aiding in the identification of species. The present study focuses on the electrochemical behavior of Cu(II) ions in the presence of urea and saccharine, offering new insights into ligand interactions and their effect on redox properties. The CV of Cu(II) in KCl solution exhibits two cathodic and two anodic peaks, indicating a two-step quasi-reversible reduction of Cu(II) to Cu(0). Increasing the scan rate shifted peak potentials towards negative voltage and enhanced peak currents, while higher Cu(II) concentrations increased both cathodic and anodic currents. In the presence of urea, Cu(II) showed significant shifts in peak potentials toward more negative values, suggesting a strong interaction that hindered reduction. Conversely, saccharine shifted peak positions towards more positive potentials, indicating a different interaction profile. Varying ligand concentrations (1–5 mM) had minimal effects on peak potentials and current, suggesting a stable 1:1 metal-ligand complexation ratio for both ligands. A linear relationship between peak current and the square root of the scan rate suggests diffusion-controlled electrode processes. These findings offer novel insights into the metal-ligand interaction dynamics and the redox behavior of Cu(II) complexes, providing potential applications in environmental remediation, catalysis, and electrochemical sensing. [Display omitted]