Tris(2-hydroxyphenyl)triazasumanene: bowl-shaped excited-state intramolecular proton transfer (ESIPT) fluorophore coupled with aggregation-induced enhanced emission (AIEE)
Tris(2-hydroxyphenyl)triazasumanene: bowl-shaped excited-state intramolecular proton transfer (ESIPT) fluorophore coupled with aggregation-induced enhanced emission (AIEE)
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DOI：
10.1039/c7qm00530j
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发表时间：
2017
影响因子：
7
通讯作者：
Patcharin Kaewmati;Y. Yakiyama;Hiroyoshi Ohtsu;M. Kawano;Setsiri Haesuwannakij;Shuhei Higashibayashi;H. Sakurai
中科院分区：
文献类型：
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作者：
Patcharin Kaewmati;Y. Yakiyama;Hiroyoshi Ohtsu;M. Kawano;Setsiri Haesuwannakij;Shuhei Higashibayashi;H. Sakurai
合成了一种具有2-（2′-羟基苯基）吡啶结构的碗状分子三（2-羟基苯基）三氮杂苏曼烯（（A）-（+）-1）。(A)-(+）-1在CH 2Cl 2中显示出单峰发射，其与三氮杂苏曼烯骨架的发射重叠，并且在高浓度下减弱，对应于激发的烯醇形式的形成。相比之下，（A）-（+）-1的单晶显示具有大的斯托克斯位移的双发射，表明存在通过激发态分子内质子转移（ESIPT）过程的激发酮形式。在含有大量不良溶剂（己烷或MeOH）和少量CH 2Cl 2的混合物的（A）-（+）-1的溶液中，通过进一步添加不良溶剂，随着发射强度的连续增加出现胶体聚集体，证明聚集诱导增强发射（AIEE）。使用扫描电子显微镜（SEM）和粉末X射线衍射（PXRD）对聚集体的形态和结构进行分析，揭示了聚集体的良好有序结构，其具有类似于（A）-（+）-1单晶的分子堆积模式。
Tris(2-hydroxyphenyl)triazasumanene ((A)-(+)-1), a bowl-shaped molecule, which possesses 2-(2′-hydroxyphenyl)pyridine moieties, was successfully synthesised. (A)-(+)-1 showed a single peak emission in CH2Cl2, which overlapped with the emission of the triazasumanene skeleton and diminished at a high concentration, corresponding to the formation of the excited enol form. In contrast, single crystals of (A)-(+)-1 exhibited a dual emission with a large Stokes shift, indicating the presence of the excited keto form by the excited state intramolecular proton transfer (ESIPT) process. In the solution of (A)-(+)-1 containing a mixture of a large amount of a poor solvent (hexane or MeOH) and a small amount of CH2Cl2, colloidal aggregates emerged with the continuous increment of emission intensity by further addition of the poor solvent, demonstrating aggregation-induced enhanced emission (AIEE). The analysis of the morphology and the structure of the aggregates using a scanning electron microscope (SEM) and powder X-ray diffraction (PXRD) revealed the well-ordered structure of the aggregates, which possessed a molecular packing pattern similar to that of an (A)-(+)-1 single crystal.