Synthesis and characterization of 2,7-linked carbazole oligomers.

A set of monodisperse 2,7-linked carbazole oligomers (3-mer, 5-mer, 7-mer, and 9-mer) was synthesized, and their photophysical, electrochemical, and thermal properties were investigated. In solutions, these oligomers exhibited bright blue emission with almost quantitative fluorescence quantum yield. The emission spectra of these oligomers in films are quite different. 3-Mer and 5-mer exhibited featureless emission spectra, whereas 7-mer and 9-mer showed well-resolved emission spectra.