Perylene Bisimide-Functionalized Triphenylmethyl Radicals Showing High Stability and Reversible Electrochemical Redox Properties

This study presents a series of triphenylmethyl monoradicals incorporating varying numbers of peripheral perylene bisimide (PBI) substituents (1PBI-TTM⋅, 2PBI-TTM⋅ and 3PBI-TTM⋅). The incorporation of electron-withdrawing PBI substituents significantly enhances the stability of these carbon radicals, enabling them to display exceptional electrochemical redox reversibility. Notably, the electronic interplay between the PBI substituents and the central triphenylmethyl core facilitates unique and reversible multi-step redox reactions. Among the reported radicals, the tris-PBI-functionalized radical (3PBI-TTM⋅) demonstrates the remarkable ability to accommodate up to seven electrons under negative potentials, forming high valence anions. This research promotes the development of highly stable carbon radicals with superior electrochemical oxidation-reduction processes, presenting promising avenues for the advancement of electric energy storage technologies.