Synthesis and properties of carbazole-containing poly(aryleneethynylenes) and poly(aryleneimines)

Novel poly(aryleneethynylenes) and poly(aryleneimines) containing carbazole units in the main chain were synthesized by polycondensation of diethynylcarbazoles with dihaloarenes, or diformyl-carbazole with phenylenediamines, and their general properties were studied. The polymers with M-w = 2700-33700 were obtained in 60-100% yields. Compared to carbazole, the UV-vis absorption of the polymers was red-shifted, which indicates the extension of conjugation length. Excited at the absorption maxima, the polymers containing ethynylene moieties showed blue or green emission with high fluorescence quantum yields (6-86%) in the solution state, while in the film state, they exhibited fluorescence at longer wavelength, which suggests the formation of excimers. On the contrary, the polymers having imine moieties showed emission with low fluorescence quantum yields (<1%).