Charge-Transfer Interactions in a Multichromophoric Hexaarylbenzene Containing Pyrene and Triarylamines
Charge-Transfer Interactions in a Multichromophoric Hexaarylbenzene Containing Pyrene and Triarylamines
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DOI：
10.1021/jo300924x
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发表时间：
2012-07-20
影响因子：
3.6
通讯作者：
Steeger, Markus
中科院分区：
文献类型：
--
作者：
Lambert, Christoph;Ehbets, Julia;Steeger, Markus
合成了两种在不同位置（三角对称和不对称排列）具有三个芘和三个三芳胺取代基的不同六芳基苯，并通过光谱研究了它们的电荷转移状态。在这些多发色团系统中，三芳胺充当电子供体，芘充当电子受体。还研究了仅具有一对供体-受体对的参考生色团。所有这些发色团在光激发时形成电荷转移态，其以中等荧光量子产率弛豫至基态。这些化合物的大部分荧光特性没有显着差异，这表明所有发色团的荧光电荷转移状态非常相似。这一观察结果表明对称发色团在几十纳秒的荧光寿命内发生对称性破缺。这种解释通过蔗糖八乙酸酯基质中的荧光激发各向异性测量得到证实。
Two different hexaarylbenzenes with three pyrene and three triarylamine substituents in different positions (trigonal symmetric and asymmetric arrangement) were synthesized, and their charge-transfer states were investigated by optical spectroscopy. In these multichromophoric systems triarylamine acts as the electron donor and pyrene as the electron acceptor. A reference chromophore with only one donor-acceptor pair was also investigated. All these chromophores form chary-transfer states upon photoexcitation which relax with a moderate fluorescence quantum yield to the ground state. The compounds do not differ significantly concerning most of their fluorescence properties, which shows that the fluorescent charge-transfer state is very similar in all chromophores. This observation indicates symmetry breaking for the symmetric chromophore within fluorescence lifetime of several tens of ns. This interpretation was substantiated by fluorescence excitation anisotropy measurements in a sucrose octaacetate matrix.