Terazulene: A High-Performance n‑Type Organic Field-Effect Transistor Based on Molecular Orbital Distribution Control

We present herein a linear expanded π-conjugation system comprising azulene units: 2,6′:2′,6″-terazulene. This simple hydrocarbon exhibits excellent n-type transistor performance with an electron mobility of up to 0.29 cm2 V–1 s–1. The lowest unoccupied molecular orbital (LUMO) is well distributed over the entire molecule, whereas the highest occupied molecular orbital (HOMO) is localized at one end. These findings indicate a disadvantage of hole carrier transport and an advantage of n-type-specific transport behavior. This system presents an unconventional concept: polarity control of OFET by molecular orbital distribution control.