Conjugated "B-entacenes": polycyclic aromatics containing two borepin rings.

The synthesis and characterization of functionalized bora-acenes (B-entacenes) where Stille and Sonogashira cross-couplings were used to attach a series of electron-donating and -withdrawing substituents is reported. Photophysical, electrochemical, and computational analyses revealed that the LUMO level can be tuned by changing the para-conjugated substituent. Furthermore, the dimethylamino-functionalized molecule exhibited intense solvatochromism due to the intramolecular charge-transfer interaction.