화학공학소재연구정보센터
Macromolecules, Vol.40, No.6, 1914-1925, 2007
Synthesis, thermal stability, and linear and nonlinear optical properties of hyperbranched polyarylenes containing carbazole and/or fluorene moieties
New diyne monomers containing carbazolyl and/or fluorenyl chromophores, namely, 3,6-diethynyl-9-phenylcarbazole (<1), 3,6-diethynyl-9-[6-(9-carbazolyl)hexyl]carbazole (2), and 2,7-diethynyl-9,9-bis[6-(9-carbazoyl)hexyl]fluorene (3), are synthesized. Alkyne polycyclotrimerizations are effected by TaX5-Ph4Sn (X = Cl, Br) and CpCo(CO)(2)-h nu catalysts, yielding soluble hyperbranched polyarylenes (hb-PAs) with high molecular weights (M-w up to similar to 1.6 x 10(5)) in high yields (up to similar to 100%). The structures and properties of the hb-PAs are characterized and evaluated by IR, NMR, UV, PL, TGA, and optical limiting analyses. Most of the hb-PAs show outstanding thermal stability (T-d up to 560 degrees C) with high weight residues (W-r up to similar to 86%) after pyrolysis at 800 degrees C. Upon photoexcitation, solutions of the hb-PAs emit strong blue light of similar to 400 nm with fluorescence quantum yields Phi(F) up to 90%. The hb-PAs show excellent optical limiting performance and strongly attenuate the powder of 8 ns pulses of 532 nm laser light.