Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Phys Chem Chem Phys. 2011 Feb 14;13(6):2044-51. doi: 10.1039/c0cp01181a. Epub 2010 Dec 20.
A few of excited state intramolecular proton transfer (ESIPT) compounds have been discovered for their aggregation induced emission enhancement (AIEE). To understand the AIEE mechanism, an ESIPT compound BTHPB (N-(4-(benzo[d]thiazol-2-yl)-3-hydroxyphenyl)benzamide) with simple structure was designed and synthesized. BTHPB showed apparent AIEE property and the emission efficiency was observed as high as 0.27 in the aggregates. On the basis of viscochromism experiments and calculations employing the linear coupling model, the restriction of the rotation between the two subunits taken place in ESIPT was considered as the main factor for the AIEE. The micro- and femtosecond transient absorption experiments offered evidence for the considerations. Additionally, we also observed a negative effect of aggregation on the fluorescence emission in the system. So the AIEE of ESIPT compound BTHPB originated from the combination effects of positive and negative factors induced by the aggregation.
一些激发态分子内质子转移（ESIPT）化合物因其聚集诱导发光增强（AIEE）而被发现。为了理解 AIEE 机制，设计并合成了具有简单结构的 ESIPT 化合物 BTHPB（N-（4-（苯并[d]噻唑-2-基）-3-羟基苯基）苯甲酰胺）。BTHPB 表现出明显的 AIEE 性质，在聚集态下观察到的发射效率高达 0.27。基于粘光实验和采用线性耦合模型的计算，认为 ESIPT 中两个亚基之间旋转的限制是 AIEE 的主要因素。微秒和飞秒瞬态吸收实验为此提供了证据。此外，我们还观察到聚集对体系中荧光发射的负面影响。因此，ESIPT 化合物 BTHPB 的 AIEE 源于聚集诱导的正负因素的组合效应。
