Bistetracene: An air-stable, high-mobility organic semiconductor with extended conjugation

We report the synthesis and characterization of bistetracene, an unconventional, linearly extended conjugated core with eight fused rings. The annellation mode of the system allows for increased stability of the conjugated system relative to linear analogues due to the increased number of Clar aromatic sextets. By attaching the appropriate solubilizing substituents, efficient molecular packing with large transfer integrals can be obtained. The electronic structure calculations suggest these large polycyclic aromatic hydrocarbons (PAHs) exhibit excellent intrinsic charge transport properties. Charge carrier mobilities as large as 6.1 cm² V^-1 s^-1 and current on/off ratios of 10⁷ were determined experimentally for one of our compounds. Our study provides valuable insight into the design of unconventional semiconductor compounds based on higher PAHs for use in high-performance devices.