Issue 92, 2019

Unveiling the formation 1 : 2 supramolecular complexes between cucurbit[7]uril and a cationic calix[4]arene derivative

Abstract

The formation of host–guest complexes between cucurbit[7]uril (CB7) and a tetracationic calix[4]arene derivative in the so-called cone conformation was investigated by 1H NMR, DOSY NMR, isothermal titration calorimetry and ESI-MS. The results point to the formation of 1 : 1, 1 : 2 and 2 : 1 CB7 : calixarene complexes with binding constants of 3 × 106 M−1, ≈2 × 102 M−1, and 9 × 104 M−1 respectively. The study demonstrates, on one hand, that despite having four potential recognition sites, the calixarene only binds two CB7 molecules and, on the other, that for sterically crowded binding motifs that prevent CB7 inclusion with optimized hydrophobic and ion–dipole interactions, the formation of 1 : 2 complexes can be observed most likely due to formation of external binding of the cationic moieties to the CB7 carbonyl portals.

Graphical abstract: Unveiling the formation 1 : 2 supramolecular complexes between cucurbit[7]uril and a cationic calix[4]arene derivative

Supplementary files

Article information

Article type
Communication
Submitted
17 set 2019
Accepted
17 out 2019
First published
21 out 2019

Chem. Commun., 2019,55, 13828-13831

Unveiling the formation 1 : 2 supramolecular complexes between cucurbit[7]uril and a cationic calix[4]arene derivative

M. Pessêgo, J. Mendoza, J. P. da Silva, N. Basílio and L. Garcia-Rio, Chem. Commun., 2019, 55, 13828 DOI: 10.1039/C9CC07280B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements