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Abstract Cucurbit[n]urils (CB[n]s) are cyclic macrocycles with rich host‐guest chemistry. In many cases, guest binding in CB[n]s results in host structural deformations. Unfortunately, measuring such deformations remains a major challenge, with only a handful of manual estimations reported in the literature. To address this challenge, we have developed the public program ElliptiCB[n], which is available on GitHub, that provides a robust and automated method for measuring the elliptical deformations in CB[n] hosts. We outline the development and validation of this approach, apply ElliptiCB[n] to measure the ellipticity of the 1113 available CB[n] structures from the Cambridge Structural Database (CSD), and directly investigate the structural deformations of CB[5], CB[6], CB[7], CB[8], and CB[10] hosts. We also report the general landscape of accessible CB[n] elliptical deformations and compare ellipticity distributions across CB[n] hosts and host‐guest complexes. We found that in almost all cases guest binding significantly impacts the distribution of host ellipticity distributions and that these distributions are dissimilar across host‐guest complexes of differently sized CB[n]s. We anticipate that this work will provide a useful approach for understanding of the flexibility of CB[n] hosts and will also enable future measurement and standardization of ellipticity measurements of CB[n]s.
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Blurring the Lines between Host and Guest: A Chimeric Receptor Derived from Cucurbituril and Triptycene
Abstract We report the synthesis and X‐ray crystal structure of a cucurbituril–triptycene chimeric receptor (1). Host1binds to guests typical of CB[6]–CB[8], but also binds to larger guests such as blue box (20) and the Fujita square (22). Intriguingly, the geometries of the1⋅20and1⋅22complexes blur the lines between host and guest in that both components fulfill both roles within each complex. The fluorescence output of1is fully quenched by the formation of complexes with pyridinium‐derived guests.
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- PAR ID:
- 10061787
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 57
- Issue:
- 27
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 8073-8078
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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