Synthesis and characterization of a novel blue electroluminescent polymer constituted of alternating carbazole and aromatic oxadiazole units
作者:Hong Meng、Zhi-Kuan Chen、Xiao-Ling Liu、Yee-Hing Lai、Soo-Jin Chua、Wei Huang
DOI:10.1039/a903215k
日期:——
A novel copolymer poly[N-(2′-ethylhexyl)-carbazole-3,6-diyl-1″,3″,4″-oxadiazole-2″,5″-diyl-2‴,5‴-dioctyloxy-1‴,4‴-phenylene-1,3,4-oxadiazole-2,5-diyl] (PCOPO) containing an electron rich carbazole moiety and an electron deficient aromatic oxadiazole unit is synthesized by a polycondensation reaction. The structure of the polymer is confirmed by FT-IR, NMR, and elemental analysis. PCOPO can be partially dissolved in THF, CHCl3, xylene, and DMSO while it can be completely dissolved in chloroform with a small amount of trifluoroacetic acid (TFA). The optical and electronic properties of the polymer are investigated by UV-Vis absorption and photoluminescence spectroscopy as well as cyclic voltammetry. The results show that the polymer films emit greenish-blue light (475 nm). The bandgap energy of the polymer is estimated by the optical method (2.82 eV) and the electrochemical measurement (2.94 eV), respectively. Both p-doping and n-doping processes are observed in cyclic voltammetric investigation. The HOMO and LUMO energies of the polymer are estimated to be 5.60 and 2.66 eV, respectively. The photophysical and electronic properties as well as the preliminary electroluminescent device result of the polymer demonstrate that it may be a promising candidate material for the fabrication of an efficient polymer light-emitting device.
一种新型共聚物聚[N-(2′-乙基己基)-咔唑-3,6-二基-1″,3″,4″-恶二唑-2″,5″-二基-2‴,5‴-二辛氧基-1通过缩聚反应合成含有富电子咔唑部分和缺电子芳香族恶二唑单元的‴,4‴-亚苯基-1,3,4-恶二唑-2,5-二基](PCOPO)。通过FT-IR、NMR和元素分析证实了聚合物的结构。 PCOPO可部分溶解于THF、CHCl3、二甲苯和DMSO,而可完全溶解于氯仿和少量三氟乙酸(TFA)。通过紫外-可见吸收光谱、光致发光光谱以及循环伏安法研究了聚合物的光学和电子性质。结果表明,聚合物薄膜发出绿蓝色光(475 nm)。聚合物的带隙能量分别通过光学方法(2.82 eV)和电化学测量(2.94 eV)估计。在循环伏安研究中观察到 p 掺杂和 n 掺杂过程。该聚合物的 HOMO 和 LUMO 能量估计分别为 5.60 和 2.66 eV。该聚合物的光物理和电子性能以及初步的电致发光器件结果表明,它可能是用于制造高效聚合物发光器件的有前途的候选材料。