- Exploiting an imidazole-functionalized polyfluorene derivative as a chemosensory material
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The synthesis and characterization of an alternating polyfluorene copolymer with imidazole ligand as the receptor in the pendent side chains were investigated. This system took the advantage of the effective π-conjugation and strong luminescence properties of the polyfluorene. Highly effective transitional metal-sensitive chemosensors were developed through metal ion-coordinating ability of imidazoles and strong luminescence of polyfluorenes. The results show that polymers containing imidazole groups act as promising active materials for application as fluorescent chemosensors.
- Zhou, Xing-Hua,Yan, Ji-Chao,Pei, Jian
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- Highly emissive excited-state intramolecular proton transfer (ESIPT) inspired 2-(2′-hydroxy)benzothiazole-fluorene motifs: Spectroscopic and photophysical properties investigation
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Tuning or switching of the solid state luminescence of organic materials is an attractive target for both basic research and practical applications. In the present study, solid state emissive compounds with very high quantum efficiencies (ΦF up
- Padalkar, Vikas S.,Sakamaki, Daisuke,Tohnai, Norimitsu,Akutagawa, Tomoyuki,Sakai, Ken-Ichi,Seki, Shu
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p. 80283 - 80296
(2015/10/05)
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- Synthesis and characterization of new red-emitting polyfluorene derivatives containing electron-deficient 2-pyran-4-ylidene-malononitrile moieties
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A novel series of red-light-emitting copolymers derived from fluorene and 2-pyran-4-ylidene-malononitrile (PM) have been synthesized through a palladium-catalyzed Suzuki coupling reaction. The polymers were characterized by FT-IR, NMR, and elemental analysis. All these polymers are completely soluble in common organic solvents, such as THF, CH2Cl2, CHCl3, and toluene, and they have good thermal stability with onset decomposition temperature (Td) of 406-407°C and glass-transition temperature (Tg) of 73-186°C. Cyclic voltammetry studies reveal that these copolymers have low-lying LUMO energy levels ranging from -3.53 to -3.57 eV and HOMO energy levels ranging from -5.77 to -5.79 eV, which indicated that they may be promising candidates for electron-transporting or hole-blocking materials in light-emitting diodes. These polymers in thin films can emit strong red photoluminescence (PL) around 641-662 nm with the corresponding additional peaks in the range 704-712 nm upon photoexcitation. Double-layer LEDs fabricated with the configuration of ITO/PEDOT/polymer/Ba/Al can emit red light with external quantum efficiencies of 0.21-0.38%. Preliminary electroluminescent (EL) results show that these polymers are novel promising candidates for red emissive materials in polymer light-emitting diodes.
- Peng, Qiang,Lu, Zhi-Yun,Huang, Yan,Xie, Ming-Gui,Han, Shao-Hu,Peng, Jun-Biao,Cao, Yong
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p. 260 - 266
(2007/10/03)
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- Synthesis and nearly monochromatic photoluminescence properties of conjugated copolymers containing fluorene and rare earth complexes
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A series of novel conjugated copolymers containing 9,9-dihexylfluorene and europium complex-chelated benzoate units in the main chain had been synthesized through a three-step process, involving Suzuki coupling copolymerization, hydrolysis of benzoate units, and postchelation. The chemical structures of the copolymers were characterized by FT-IR, 1H NMR, 13C NMR, GPC, and ToF-SIMS. The copolymers exhibited relatively high glass transition temperatures after incorporation of the rare earth complexes. The photoluminescence (PL) properties of the copolymer complexes in solution and in film form were investigated. Intramolecular energy transfer from the fluorene groups to the europium complex occurred in diluted solutions of the copolymer. The efficiency of this process depended strongly on the structure of the ligands for the europium complex and the composition of the copolymers. The PL spectra of the copolymer complexes consisted of two emission bands, one in the 350-550 nm region and another at around 612 nm, corresponding to the π* → π transitions of the fluorene moieties and the f-f transitions of the europium ions, respectively. In the copolymer films cast from solutions, emission from the fluorene groups could be suppressed, and the absorbed excitation energy was transferred effectively to the europium complexes in the copolymer. Nearly monochromatic red emission (with a line width of about 4 nm) was detected under UV excitation at room temperature.
- Ling,Kang,Neoh,Huang, Wei
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p. 6995 - 7003
(2007/10/03)
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- New efficient blue light emitting polymer for light emitting diodes
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The synthesis, by the Suzuki coupling reaction, of a novel soluble blue light emitting polymer, poly{(9,9-dihexyl-2,7-fluorene-alt-co-[2,5-bis(decyloxy)-1,4-phenylene]} (PDHFDDOP) is reported. PDHFDDOP exhibits photoluminescence (PL quantum efficiency of
- Yu, Wang-Lin,Pei, Jian,Cao, Yong,Huang, Wei,Heeger, Alan J.
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p. 1837 - 1838
(2007/10/03)
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