The chemical modification of bridging groups of the pillar[]arenes is an important way to functional derivatization and expand the application fields. So far, however, there have been few reports on this issue. On the basis of experimental reports, a series of thiapillar[5]arene structures with sulfur, sulfoxide and sulfone as bridging groups are proposed in this work. By using density functional theory (DFT) calculations, thiapillar[5]arenes are studied systematically at the ωB97XD/6-311G(d,p) level of theory. All the structures have regular pentagonal shape with the point group of D. The substitution of bridging methylene by sulfur leads to a significant enlargement in the molecular cavity, an extension of the spatial delocalization of the electrons, and a redshift of the absorption spectrum. The bridging groups of sulfoxide and sulfone can greatly improve the solvent effects in polar solvents, which is followed by the weakening of the pi-electron donating capacity inside the molecular cavity. Thiapillar[5]arenes have rich host–guest chemistry and can recognize a variety of guest species. Interestingly, the inclusion of thiapillar[5]arenes to ferrocene is a synergistic result of electronic and spatial effects. The sulfur-containing derivatizations of pillar[]arenes are expected to expand the application prospects in supramolecular biology and electrochemistry related fields.

中文翻译：

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Thiapillar[5]芳烃：结构、性质和主客体化学

对柱芳烃桥基进行化学修饰是功能衍生化、拓展应用领域的重要途径。但迄今为止，关于这一问题的报道还很少。在实验报告的基础上，本工作提出了一系列以硫、亚砜和砜为桥联基团的硫杂柱[5]芳烃结构。通过密度泛函理论(DFT)计算，在ωB97XD/6-311G(d,p)理论水平上对硫杂环芳烃[5]芳烃进行了系统研究。所有结构均具有正五边形，点群为D。桥接亚甲基被硫取代导致分子空腔显着扩大，电子空间离域范围扩大，吸收光谱红移。亚砜和砜的桥连基团可以大大改善极性溶剂中的溶剂效果，随之而来的是分子腔内的π电子供体能力减弱。 Thiapillar[5]芳烃具有丰富的主客体化学性质，可以识别多种客体物种。有趣的是，将硫杂柱[5]芳烃纳入二茂铁中是电子效应和空间效应的协同结果。柱芳烃的含硫衍生化有望拓展在超分子生物学和电化学相关领域的应用前景。