Novel 2,7-Linked Carbazole Trimers as Model Compounds for Conjugated Carbazole Polymers
Novel 2,7-Linked Carbazole Trimers as Model Compounds for Conjugated Carbazole Polymers
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DOI：
10.1021/cm040142i
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发表时间：
2004-07
影响因子：
8.6
通讯作者：
M. Sonntag;P. Strohriegl
中科院分区：
文献类型：
--
作者：
M. Sonntag;P. Strohriegl
本文提出了一种新的N-烷基化2，7-二溴咔唑的合成方法，并用Suzuki交叉偶联法合成了2，7-二溴咔唑三聚体。对这些化合物的热、光学和电化学性质进行了表征，并与同样通过Suzuki反应制备的类似的荧烯三聚体进行了比较。咔唑和荧三聚体的热稳定性超过300°C，能够形成分子玻璃。咔唑三聚体中只有一种是结晶的。咔唑和荧三聚体都表现出明亮的蓝色荧光，最大荧光波长在393 nm处，表现出相似的吸收特性。循环伏安实验表明，荧三聚体具有良好的电化学稳定性。它们的HOMO和LUMO水平分别为−5.6 eV和−2.5 eV。与荧烯相反，2，7-偶氮咔唑三聚体在循环伏安实验中表现出不可逆氧化。
In this paper we present a new synthesis for N-alkylated 2,7-dibromocarbazoles, from which 2,7-linked carbazole trimers have been synthesized by Suzuki cross coupling. The compounds were characterized regarding their thermal, optical, and electrochemical properties and compared to analogous fluorene trimers, which also have been prepared by Suzuki reactions. The carbazole and fluorene trimers exhibit thermal stabilities of more than 300 °C and are able to form molecular glasses. Only one of the carbazole trimers is crystalline. Both carbazole and fluorene trimers exhibit a bright blue fluorescence with a maximum at 393 nm and show similar absorption characteristics. Cyclovoltammetric experiments revealed the electrochemical stability of the fluorene trimers. Their HOMO and LUMO levels are at −5.6 and −2.5 eV, respectively. In contrast to the fluorenes, the 2,7-linked carbazole trimers showed nonreversible oxidations in the CV experiments.