1,1′-Disubstituted-2,3,4,5-tetraphenylsiloles incorporating triptycene moieties Tp-DMTPS and Tp-MPTPS were prepared and characterized. Like other 2,3,4,5-tetraphenylsiloles, both compounds exhibit aggregation-induced emission (AIE) behavior. Unexpectedly, the solid state PL emission of Tp-DMTPS show dependence according to the degree of crystallinity of the powders. While precipitates display a blue-green emission, microcrystalline powders emit in the yellow-orange region. Moreover a rare reversible mechanohypsochromic phenomenom is observed: upon grinding, the emission of a micro-crystalline powder changes from yellow-orange to blue-green, the original emission being restored by annealing the sample. The mechanism of this blue-shift upon crystal grinding was investigated by X-ray diffraction, ¹³C CP-MAS NMR and DFT calculations. Under mechanical stress, strong intermolecular CH/π interactions are found to promote the less energetically stable population of conformers present in the crystals, leading to this blue-shift. Finally the influence of the triptycene moieties on the thermal and structural stability of Tp-DMTPS and Tp-MPTPS was studied. Compared with DMTPS and MPTPS parents, a general enhancement of the properties is noticed, especially when used as active layer in OLED fabrication. Our results suggest that the attachment of triptycene moieties to π-conjugated molecules is an interesting way to improve their thermal, structural and photophysical properties for sensing or optoelectronic applications.

中文翻译：

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将三萜与Silole连接：卓有成效的联系

制备并表征了掺有三茂基部分Tp-DMTPS和Tp-MPTPS的1,1'-二取代的2,3,4,5-四苯基甲硅烷基。像其他的2,3,4,5-四苯基甲硅烷基一样，这两种化合物都表现出聚集诱导发射（AIE）行为。出乎意料的是，Tp-DMTPS的固态PL发射根据粉末的结晶度显示依赖性。沉淀物显示出蓝绿色发射，而微晶粉末发射出黄橙色区域。此外，观察到了罕见的可逆机械变色现象：研磨后，微晶粉末的发射从橘黄色变为蓝绿色，通过对样品进行退火可以恢复原始发射。通过X射线衍射研究了晶体研磨时蓝移的机理，[ ^13]C CP-MAS NMR和DFT计算。在机械应力下，发现强分子间CH /π相互作用促进晶体中存在的能量稳定度较低的构象异构体群，从而导致这种蓝移。最后研究了三并茂基团对Tp-DMTPS和Tp-MPTPS的热稳定性和结构稳定性的影响。与DMTPS和MPTPS母体相比，已注意到其性能普遍增强，尤其是在OLED制造中用作有源层时。我们的结果表明，将三萜部分连接到π共轭分子上是改善传感，光电应用的热，结构和光物理性质的有趣方法。