醚类冠穴状配体的主机和一个碳正离子之间主-客体复合,六氟磷酸鎓进行了研究。1 H NMR,NOESY NMR和电喷雾电离质谱法来表征这些包合络合物。的对比试验11 H NMR和结合常数表明穴状配体是六氟磷酸鎓比相应的简单冠醚好得多主机。C-H⋯O氢键键合,面-面π堆积相互作用,和电荷转移的相互作用被认为是主要驱动力为这些主-客体复合物的形成。这些多种非共价相互作用可共同促进复合物的形成并显着增强复合物的稳定性。此外,基于二苯并-24-冠-8之间的穴状配体络合4和六氟磷酸鎓7可以通过添加KPF被可逆地控制6 然后DB18C6在1:1级乙腈/氯仿,提供用于超分子化学新阳离子响应性主客体识别基序。
1,2-Bis[N-(N′-alkylimidazolium)]ethane salts as new guests for crown ethers and cryptands
作者:Minjae Lee、Zhenbin Niu、Daniel V. Schoonover、Carla Slebodnick、Harry W. Gibson
DOI:10.1016/j.tet.2010.07.010
日期:2010.8
1,2-Bis[N-(N′-alkylimidazolium)ethane salts form complexes presumed to be pseudorotaxanes with crown ether and cryptand hosts. The association constants of 1,2-bis[N-(N′-butylimidazolium)]ethane bis(hexafluorophosphate) with dibenzo-24-crown-8 and a dibenzo-24-crown-8-based pyridyl cryptand were estimated as 24 (±1) and 348 (±30) M−1, respectively, in acetonitrile at 25 °C. The pseudorotaxane-like
High-Yielding Syntheses of Crown Ether-Based Pyridyl Cryptands
作者:Terry L. Price、Hanlie R. Wessels、Carla Slebodnick、Harry W. Gibson
DOI:10.1021/acs.joc.7b01389
日期:2017.8.4
Pyridinium bis(trifluoromethylsulfonyl)imide (PyTFSI)-templated syntheses of 2,6-pyridyl cryptands of cis(4,4′)-dibenzo-30-crown-10 (3a), the p-bromobenzyloxy derivative 3b, bis(m-phenylene)-32-crown-10 (5), cis(4,4′)-dibenzo-27S-crown-9 (7), cis(4,4′)-dibenzo-27L-crown-9 (9), and cis(4,4′)-dibenzo-24-crown-8 (11) are reported. Here we provide a fast (12 h), high-yielding (89%, 74%, 80%, and 62% for
studied. Formation of [2]pseudorotaxanesfrom a dibenzo-24-crown-8-based cryptand and these vinylogous viologens can be reversibly controlled by adding and removing potassium cation in acetone. Furthermore, the complexation between a bis(m-phenylene)-32-crown-10-based cryptand and a vinylogous viologen exhibits a high association constant, 1.18 × 106 M–1 in acetone, and leads to the formation of a supramolecular
formed between two crown ether-based cryptands and a 1,2-bis(4-pyridinium)ethanederivative3 are reported. By self-assembly of cis-dibenzo-24-crown-8-based cryptand 1 and guest 3, a [3]pseudorotaxane was formed in solution, which further formed a supramolecular poly[3]pseudorotaxane structure in the solid state driven by π-π stacking interactions. Meanwhile, a [2]pseudorotaxane, obtained from self-assembly