Used as a redox indicator in analytical chemistry due to its reversible color change upon electron transfer. Commonly employed in electrochemical sensors and assays to monitor oxidation-reduction reactions. Also applied in the development of viologen-based systems for electrochromic devices, where it contributes to color switching in smart windows and displays. Its strong electron-accepting properties make it suitable for use in charge-transfer complexes and supramolecular chemistry. Additionally, it serves as a precursor in the synthesis of functional materials for energy storage and photochemical applications.