Synthesis of π-conjugated copolymer with dibenzo[d,d′]benzo[1,2-b:4,5-b′]difuran unit in the main chain

New pi-conjugated polymers with dibenzo[d,d']benzo[1,2-b:4,5-b']difuran (DBBDF) unit in the main chains were synthesized. Copolymerization of 6,12-diiodo-DBBDF with p-diethynylbenzene or 2,7-diethynylfluorene derivative under Sonogashira-Hagiwara coupling-reaction condition gave the corresponding copolymer The resulting copolymers were soluble in organic solvents such as tetrahydrofuran and chloroform. In UV-vis absorption spectra, both copolymers showed red-shifted spectra compared to their monomer units. In the chloroform solutions, the copolymer with DBBDF and p-diethynylbenzene units showed yellowish-green emission, while the copolymer with DBBDF and 2,7-diethynylfluorene units did greenish-blue emission. (C) 2009 Elsevier B.V. All rights reserved.