π-Dimers of core-unsubstituted perylene diimide radical anion: Synthesis, dissociation and high current-responsive to alkyl primary amine vapor

Abstract π-dimer dissociation Purely organic radical ions dimerize in solution at low temperature, to form the isolated dimers with long multi-center bonds, which shows the metastability in solution. The metastability of radical π-dimers in solution limits the research on its properties and application. The isolated π-dimers of two types of core-unsubstituted perylene diimide radical anion in solution at room temperature were first found in here. The diamagnetic π-dimers with hydroxyl at amine position can be dissociated into its radical anions in solution when adding alkyl primary amines. Moreover, the thin film device of the π-dimer2 showed current-responsive of 11,800 times within volatile alkyl primary amines at voltage of 1 V, and the limit of detection was 209 ppb.