NMR study of the reversible complexation of xenon by cucurbituril

Citation
M. El Haouaj et al., NMR study of the reversible complexation of xenon by cucurbituril, J CHEM S P2, (5), 2001, pp. 804-807
Citations number
26
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
ISSN journal
1472779X → ACNP
Issue
5
Year of publication
2001
Pages
804 - 807
Database
ISI
SICI code
1472-779X(2001):5<804:NSOTRC>2.0.ZU;2-I
Abstract
The interaction of xenon with cucurbituril, a synthetic receptor, in aqueou s solutions is investigated by Xe-129 and H-1 NMR spectroscopy. Xenon is re versibly trapped into the cavity to form a 1:1 host-guest complex. The exch ange between the free and the complexed xenon is slow on the Xe-129 NMR che mical shift time scale but fast on the H-1 NMR chemical shift time scale. T he apparent association constant of xenon for cucurbituril can be obtained from analysis of the H-1 spectra and is estimated to be around 200 M-1 at 2 98 K. Interestingly, even though no H-bonding or electrostatic interactions play a role in the stabilisation of the complex, its stability is comparab le to the stability of cucurbituril complexes with certain aryl- and alkyl- ammonium ions.