作者:Hongwei Liu、Shuai Wang、Yanhong Luo、Wenhong Tang、Gui Yu、Lin Li、Chuanfu Chen、Yunqi Liu、Fu Xi
DOI:10.1039/b105905j
日期:2001.11.23
A soluble PPV derivative (C-PPV) with high molecular weight, substituted with a crown ether in direct π-conjugation at the 2,3-position, has been synthesized via a modified Gilch route in good yield. The double layer LED based on C-PPV (ITO/C-PPV/Alq3/Al) exhibits a high luminance of 730 cd m−2, and emits yellow–green light with an external EL quantum efficiency of 0.04%. The fluorescence attenuation of the polymer solution is found upon K+, Na+, or Li+ binding. The AFM provides high-resolution images of C-PPV in thin films constructed from a very dilute solution in the absence and presence of metal ions. Worm-like images with well-defined width and height are observed only in the presence of K+, which is in striking contrast to the individual ball shape of C-PPV molecules in the absence of K+, or in
the presence of Na+, or Li+. It was also observed that the worm-like images grew longer and longer as the solution of C-PPV in the presence of K+ stood longer. These unique self-assembling features of the C-PPV molecules may be attributed to the complexation of K+.
通过改进的 Gilch 路线合成了一种高分子量的可溶性 PPV 衍生物(C-PPV),该衍生物在 2,3 位直接与冠醚发生 π 共轭反应,收率很高。基于 C-PPV 的双层 LED(ITO/C-PPV/Alq3/Al)显示出 730 cd m-2 的高亮度,并能发出黄绿光,外部 EL 量子效率为 0.04%。当 K+、Na+ 或 Li+ 结合时,聚合物溶液的荧光会衰减。原子力显微镜可在没有和有金属离子存在的情况下,提供由非常稀的溶液构建的薄膜中 C-PPV 的高分辨率图像。只有在 K+ 存在的情况下,才能观察到具有明确宽度和高度的蠕虫状图像,这与 C-PPV 分子在 K+ 不存在、Na+ 或 Li+ 存在时的球状形状形成了鲜明对比。此外,我们还观察到,随着 K+ 存在时 C-PPV 溶液停留的时间越长,蠕虫状图像也越来越长。C-PPV 分子的这些独特的自组装特征可能是由于 K+ 的络合作用。