Bithiophene-fused benzo[c]phospholes: Novel P,S-Containing hybrid pi-conjugated systems with small HOMO-LUMO energy gaps

摘要

Bithiophene-fused benzo[c]phospholes were successfully prepared by a Ti-II-mediated cyclization of dialkynylated bithiophene derivatives. It was revealed that the optical and electrochemical properties of the bithiophene-fused benzo[c]phospholes are deeply related to the pi-conjugation modes at the fused bithiophene subunits. Both experimental and theoretical results demonstrate that the appropriately ringannulated systems are potential emitters with small HOMO-LUMO energy gaps covering the orange-to-red region due to the efficient pi-electron delocalization over the three conjugated heterole rings. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).