以1,3,5-三嗪为核,四苯基乙烯为端基,合成了两种新型的星状结构分子2,4,6-三(4.(1,2,2-三苯基乙烯基)苯基)-1,3,5-三嗪(TTPE—Tr)和2,4,6-三(4-(1,2,2-三苯基乙烯基)-4-联苯基)-1,3,-三嗪(TTPE-Ph-Tr),并利用核磁共振(NMR)、离子化质谱(MALDI-MS)及元素分析等对其进行了结构表征.通过混合溶剂四氢呋喃(THF)/水析出实验显示,化合物TTPE-Tr和TTPE-Ph.Tr在纯THF溶剂中无荧光,而在THF/水混合溶剂中,当水体积分数增加时呈现荧光增强现象.通过紫外-可见(UV-Vis)光谱、荧光(PL)光谱、扫描电子显微镜(SEM)证实荧光量子效率的提高是由于分子内电子旋转受限(RIR)导致的.同时发现化合物TTPE-Tr具有力致变色性质,简单的研磨使其发光颜色(蓝绿光到黄绿光)及发光强度(ФF,24.4%到14.7%)发生了明显的改变.UV-Vis光谱、PL光谱、X射线衍射(XRD)、荧光寿命和荧光量子效率等测试结果显示,这种现象是由于力刺激改变了TTPE-Tr的分子堆积形式导致的.热分析结果显示化合物TTPE-Tr和TTPE-Ph-Tr的热分解温度分别为464和385℃,具有良好的热稳定性.
Two star-shaped molecules consisting of a 1,3,5-triazine core with peripheral tetraphenylethylene moieties, 2,4,6-tris(4-(1,2,2-triphenylvinyl)phenyl)-1 ,3,5-tdazine (TTPE-Tr) and 2,4,6-tris(4-(1,2,2- triphenyIvinyl)- [1,1-biphenyl]-4-yl)-1,3,5-triazine (TTPE-Ph-Tr), have been synthesized. These compounds were characterized by nuclear magnetic resonance spectroscopy (NMR), matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and elemental analysis. Both compounds exhibited aggregation-induced emission enhancement (AIEE) properties during addition of water to their tetrahydrofuran (THF) solutions. Results from UV-Vis spectroscopy, photoluminescence (PL) spectroscopy, and scanning electron microscopy (SEM) demonstrated that the restricted intra-molecular bond rotation (RIR) reduced non-radiative transitions in these compounds in the aggregated state, resulting in the fluorescence quantum yields (ФF) increase. TTPE-Tr was also found to display mechanofluorochromic behavior. This compound, a blue-green powder (ФF=24.4%, λem=508 rim), exhibited relatively weak yellow/green emission(ФF=14.7%, λem=517 nm) upon grinding. The phase transition process responsible for this mechanochromism was confirmed by PL spectroscopy, X-ray diffraction (XRD) and time-resolved fluorescence spectroscopy. Thermal analysis of TTPE-Tr and TTPE-Ph-Tr showed that these compounds possess excellent thermal stability, with decomposition temperatures of 464 and 385 ℃, respectively.