Novel diethynylcarbazole macrocycles: Synthesis and optoelectronic properties

Diethynylcarbazole macrocycles 1b and 2b have been synthesized by oxidative coupling of appropriate precursors. In particular, macrocycle 2b was prepared by bimolecular Pd-catalyzed oxidative coupling in 35% isolated yield. The spectroscopic properties of these macrocycles and their precursors were measured in detail. The films of these macrocycles by the dipping method and the Langmuir-Blodgett technique were fabricated to study their photoinduced charge-transfer properties. A rapid and steady cathodic photocurrent of these films was produced in a three-electrode cell when irradiated with white light. A possible mechanism of the photoinduced electron-transfer pathway was suggested.