Electrochemistry of Diquinonyl Amines with an Internal Proton Source

It is well established that quinones play an important role in various biological systems. Studying electrochemical properties of quinones affords fundamental knowledge of semi-quinone radicals formation in vivo and in vitro in different media. Following our previous work on electrochemical properties of various quinonyl amines [1], Scheme 1 below describes seven diquinonyl amines. Noteworthy that six of them ( 1 - 6 ) contain an internal proton donor (‘NH’) except for the seventh one ( 7 ), in which both quinone moieties are attached to ‘NMe’ group. Their redox potentials were measured by cyclic voltammetry in dichloromethane [2]. The results show a strong dependence of the nature of substituent on the first reduction potentials, and that protonation of diquinonyl amines is feasible by internal proton source even in a non-polar medium. References [1] S. Bittner, S. Gorohovsky, O. Paz-Tal (Levi), J.Y. Becker, Amino Acids , 2002 , 22 , 71-93 [2] G. Temtsin-Krayz, S. Bittner, A. Dhiman and J.Y. Becker, "Electrochemistry of Quinones with Respect to their Role in Biomedical Chemistry", Chem. Rec., 2021 , 21 .