Second Generation of Cata-Annulated Azaacene Bisimides: Towards Electron-Accepting Materials.

This work presents the 2nd generation of cata-annulated azaacene bisimides with increased electron affinities (up to -4.38 eV) compared to their consaguine conventional azaacenes. These compounds were synthesized via Buchwald-Hartwig coupling followed by oxidation with MnO2 . Crystal structure engineering through variation of the bisimide substituents furnished crystalline derivatives suitable for proof of concept organic field effect transistors with electron mobilities up to 2.2×10-4  cm2 (Vs)-1 . Moreover, we were able to characterize the charge carrying species, the radical anion, using electron paramagnetic resonance and absorption measurements.