Boron-Stabilized Planar Neutral π‑Radicals with Well-Balanced Ambipolar Charge-Transport Properties

Organic neutral π-monoradicals
are promising semiconductors
with balanced ambipolar carrier-transport abilities, which arise from
virtually identical spatial distribution of their singly occupied
and unoccupied molecular orbitals, SOMO­(α) and SOMO­(β),
respectively. Herein, we disclose a boron-stabilized triphenylmethyl
radical that shows outstanding thermal stability and resistance toward
atmospheric conditions due to the substantial spin delocalization.
The radical is used to fabricate organic Mott-insulator transistors
that operate at room temperature, wherein the radical exhibits well-balanced
ambipolar carrier transport properties.