Acridino[2,1,9,8-klmna]acridine Bisimides: An Electron-Deficient π-System for Robust Radical Anions and n-Type Organic Semiconductors.

We report the synthesis and properties of acridino[2,1,9,8-klmna]acridine bisimide (AABI), which is a nitrogen-doped anthanthrene with two imide functionalities. AABI exhibits excellent electron affinity as evident by its low-lying LUMO level (-4.1 eV vs. vacuum). Single-electron reduction of one AABI derivative afforded the corresponding radical anion, which is stable under ambient conditions. The photoconductivity measurement suggests that the intrinsic electron mobility of an N-phenethyl AABI derivative obeys a band-transport model. Accordingly, the single-crystal organic field-effect transistor (OFET) device achieved an electron mobility of 0.90 cm2 V-1 s-1. The vacuum-deposited OFET device consisting of a polycrystalline sample exhibited a high electron mobility of up to 0.27 cm2 V-1 s-1 even in air. This study highlights dual incorporation of both imide substituents and imine-type nitrogen atoms represents an effective strategy to create novel electron-deficient π-systems.