Related Experiment Video
Updated: Jun 5, 2026

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
Anion recognition and cation-induced molecular motion in a heteroditopic [2]rotaxane
Alexandre V Leontiev1, Charlotte A Jemmett, Paul D Beer
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, UK.
Abstract:
A heteroditopic [2]rotaxane consisting of a calix[4]diquinone-isophthalamide macrocycle and 3,5-bis-amide pyridinium axle components with the capability of switching between two positional isomers in response to barium cation recognition is synthesised. The anion binding properties of the rotaxane's interlocked cavity together with Na(+) , K(+) , NH(4) (+) and Ba(2+) cation recognition capabilities are elucidated by (1) H NMR and UV-visible spectroscopic titration experiments. Upon binding of Ba(2+) , molecular displacement of the axle's positively charged pyridinium group from the rotaxane's macrocyclic cavity occurs, whereas the monovalent cations Na(+) , K(+) and NH(4) (+) are bound without causing significant co-conformational change. The barium cation induced shuttling motion can be reversed on addition of tetrabutylammonium sulfate.
More Related Videos
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
10:52Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Related Concept Videos
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous overlap of p...
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
π Molecular Orbitals of the Allyl Cation and Anion