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Two novel fluorene-based copolymers (PFSD and PFMD) containing squaric acid or maleimide unit in the main chain were synthesized in good yields by Suzuki coupling reaction. The resulting polymers possess excellent thermal stability, high electron affinity and high photolurninescence (PL) quantum yields. They can fluoresce in yellow-light range due to either the charge transfer between a fluorene segment and an electron-deficient containing squaric acid/maleimide segment of the polymers or the Forrster energy transfer between different polymer chains.The results from PL measurements of the isothermally heated polymer thin films show that the commonly observed aggregate excimer formation in polyfluorenes is very effectively suppressed in these two polymers due to the nonlinear structures of maleimide and squaric acid moieties. Double-layer polymer light-emitting diodes (PLED) were fabricated using the resulting polymers as the emitting layers and Ba or Mg:Ag(V:V=10:1) as cathodes.All the devices show bright yellow emission (562-579nm) with different maximum external quantum efficiencies (0.006%-1.13%). Compared with the other devices, indium-tin oxide (ITO)/polyethylenedioxythiophene (PEDOT):polystyrene sulfonic acid (PSS)/PFMD/Mg:Ag has the higher maximum external quantum efficiency of 1.13% at 564cd/m^2 with a bias of 8.4V. 相似文献
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杂氮冠醚化Schiff碱钴(Ⅱ)配合物模拟磷酸二酯水解酶的研究 总被引:3,自引:6,他引:3
含杂氮冠醚的Schiff碱过渡金属配合物作为模拟水解酶被用于催化BNPP水解,讨论了两种杂氮冠醚化单Schiff碱钴(Ⅱ)配合物催化BNPP水解的动力学和机理,分析了反应体系的特征光谱变化。提出了配合物催化BNPP水解的动力学数学模型,结果表明,在反应过程中形成中间物种的假设是合理的;随着缓冲溶液pH的增大,两种配合物催化BNPP水解速率提高;两种配合物在催化BNPP水解中表现出好的催化活性。 相似文献
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在环上含多羧基的冠状聚合物能吸附海水中铀。我们继前文合成了一类在主链上含多个羧甲基的聚酰胺酸3_(a-c)。为了考查冠醚环和羧基对聚合物吸附金属离子的影响,还制备了无冠醚环的3_d,以及3_(a-d)的无羧基衍生物聚酰亚胺4_(a-d)作对照物。其合成路线如下: 相似文献
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由乙二胺四乙酸合成一类新型的N,N′-二羧甲基大环醚双内酯和大环胺双内酰胺 总被引:1,自引:0,他引:1
EDTA脱水成二酐后,与多缩乙二醇或α,ω-二胺反应,分别得到了大环醚双内酯(Ⅰ—Ⅳ)和大环胺双内酰胺(Ⅴ—Ⅷ)。各产物的结构均经红外、核磁、分子量和元素分析鉴定。 相似文献