Investigations on the electrochemical properties of new conjugated polymers containing benzo[c]cinnoline and oxadiazole moieties
Investigations on the electrochemical properties of new conjugated polymers containing benzo[c]cinnoline and oxadiazole moieties
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DOI：
10.1016/j.polymer.2011.10.059
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发表时间：
2011-12
期刊：
影响因子：
4.6
通讯作者：
Jyh‐Chien Chen;Hsin-Chung Wu;Chi-Jui Chiang;Lili Peng;Tuo Chen;Li-Rui Xing;Shun‐Wei Liu
中科院分区：
文献类型：
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作者：
Jyh‐Chien Chen;Hsin-Chung Wu;Chi-Jui Chiang;Lili Peng;Tuo Chen;Li-Rui Xing;Shun‐Wei Liu
设计了一条四步反应路线合成3，8-苯并[c]噌啉二甲酸（4）。以可溶性聚酰肼前体PHA（I）和PHA（T）为原料，通过热环化脱水反应，得到了含苯并[c]噌啉和恶二唑结构的新型共轭聚合物POXD（I）和POXD（T）。在CV阴极扫描过程中，观察到这些新的共轭聚合物的两个还原峰。结合分子模拟的结果，我们认为第一次还原反应发生在恶二唑基团，第二次还原反应发生在苯并[c]噌啉基团。这表明恶二唑比苯并[c]噌啉具有更强的电子亲合势。我们提出了一个机制来解释这两个阶段的还原过程。由于苯并[c]噌啉和恶二唑部分的平面和电子接受能力，POXD（I）和POXD（T）表现出非常低的LUMO（−3.42和−3.45 eV）和HOMO（−6.23和−6.27 eV）能级。它们可以用作OLED应用的空穴阻挡层或电子注入层。
A four-step route was designed to synthesize 3,8-benzo[c]cinnoline dicarboxylic acid (4). New conjugated polymers, POXD (I) and POXD (T), containing benzo[c]cinnoline and oxadiazole moieties, were obtained by thermal cyclodehydration of their soluble polyhydrazide precursors PHA (I) and PHA (T), respectively. Two reduction peaks were observed for these new conjugated polymers during CV cathodic scan. From the CV voltammograms combined with the results from molecular simulation, we concluded that the first reduction occurred at oxadiazole moiety and benzo[c]cinnoline moiety was responsible for the second reduction. It indicates that oxadiazole has stronger electron affinity than benzo[c]cinnoline. We proposed a mechanism to explain this two-stage reduction process. Due to the planar and electron-accepting ability of benzo[c]cinnoline and oxadiazole moieties, POXD (I) and POXD (T) exhibited very low LUMO (−3.42 and −3.45 eV) and HOMO (−6.23 and −6.27 eV) energy levels. They can be used as hole-blocking or electron-injection layers for OLED applications.