Spectroelectrochemical properties of 8-aminoquinoline: voltammetric and computational studies

8-Aminoquinoline (8AQ) is the building block for many medicinal molecules. However, the redox properties of 8AQ, which are important for understanding the redox stability of drugs based on 8AQ in the human body, have not been studied in detail before. We have used cyclic voltammetry and pulse voltammetric techniques to investigate the anodic as well as the cathodic electrochemical behaviour of 8AQ in a wide pH range. We have also applied UV-Vis spectroscopy to get a better understanding of the deprotonation of 8AQ due to pH changes. In addition, quantum chemical studies exploring the energy landscapes of the possible oxidations and reductions were performed, advancing our understanding of the electrochemical phenomena. The results indicate that the oxidation pathway of 8AQ strongly depends on the pH of the solution while reduction occurs according to a single pathway.