School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, 69978, Tel Aviv, Israel.
Department of Organic Chemistry, Israel Institute for Biological Research, Ness-Ziona, 74000, Israel.
Chemistry. 2020 Sep 1;26(49):11250-11255. doi: 10.1002/chem.202000972. Epub 2020 Aug 10.
Supramolecular systems in water are of paramount importance and those based on hydrogen bonds are both intriguing and scarce. Here, after studying the peculiar host-guest complexes formed between per-dimethylamino-pillar[5]arene (1) and the bis-sulfonates 2 a-c, we describe the formation of the first hydrogen-bond-based supramolecular pentagonal boxes (SPBs), which are stable in water. These pH-responsive SPBs are constructed from 1 as a body, benzene polycarboxylic acids 3 a,b as lid compounds, and 2 a-c as guests. We demonstrate that encapsulation of 2 a-c in pillar[5]arene 1 and in the highly stable water-soluble SPBs, that is, 1(3 a) and 1(3 b) , is both temperature and pH dependent and, quite interestingly, depends, on the nature of the lid compounds used for capping the boxes even at high pH. We also highlight the difference in the H NMR characteristics of 2 b and 2 c in the cavity of 1 and the SPBs.
在水中的超分子体系至关重要，而基于氢键的超分子体系既有趣又稀少。在这里，在研究了脒基修饰的[5]轮烷（1）与双磺酸盐 2a-c 之间形成的特殊主客体配合物之后，我们描述了第一个基于氢键的超分子五边形盒（SPB）的形成，该超分子五边形盒在水中稳定存在。这些对 pH 响应的 SPB 由 1 作为主体、苯多羧酸 3a,b 作为盖子化合物和 2a-c 作为客体构建而成。我们证明了客体 2a-c 在[5]轮烷 1 中的包合以及在高度稳定的水溶性 SPB 中的包合，即 1(3a) 和 1(3b)，既依赖于温度也依赖于 pH，而且，非常有趣的是，即使在高 pH 值下，盖子化合物的性质也会影响盒子的封装。我们还强调了客体 2b 和 2c 在 1 的空腔中和 SPB 中的 1H NMR 特征的差异。
