摘要
High molecular weight hyperbranched polyarylenes were synthesized in high yields by one-pot copolycyclotrimerizations of 2,5-diethynylthiophene (1), 4,4' -biphenyldiyne (2) and 2,7-diethynylfluorenes (3) with l-heptyne (4) and 1-dodecyne (5) using TaCl5·Ph4Sn catalysts in toluene. The structures and properties of the polymers were characterized and evaluated by 1R, NMR, TGA, UV, fluorescence and optical limiting analyses. All the polymers possess high thermal stability and emit strong blue light upon UV irradiation, whose intensities are higher than that from poly( 1 -phenyl-1 -octyne) ( PPO) , a well-known highly luminescent disubstitut-ed polyacetylene. Little aggregation-induced red shift in the photoluminescence is observed in the thin films of the polymers.
基金
Jointly funded by the Hongkong Research Grants Council (HKUST6149/97P,and 6187/99P) and Natural Science Foundation of Hubei Province(2000J024)
