[2]Rotaxanes containing pyridinium-phosphonium axles and 24-crown-8 ether wheels

Norma Georges; Stephen J Loeb; Jorge Tiburcio; James A Wisner

doi:10.1039/B407653B

[2]Rotaxanes containing pyridinium-phosphonium axles and 24-crown-8 ether wheels

Org Biomol Chem. 2004 Oct 7;2(19):2751-6. doi: 10.1039/B407653B. Epub 2004 Sep 6.

Authors

Norma Georges¹, Stephen J Loeb, Jorge Tiburcio, James A Wisner

Affiliation

¹ Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada.

PMID: 15455146
DOI: 10.1039/B407653B

Abstract

A triethylphosphonium group attached to a pyridinium ethane moiety can be used as an axle for the self-assembly of [2]pseudorotaxanes and [2]rotaxanes. Although [2]pseudorotaxane formation is limited due to the bulk of the PR4+ group, [2]rotaxanes can be formed utilising 24-crown-8 ether, benzo-24-crown-8 ether and naphtho-24-crown-8 ether. The synthesis of these [2]rotaxanes and the X-ray structure of the [2]rotaxane containing a 24-crown-8 ether wheel are described. When the crown ether contains an aromatic group two possible conformational isomers exist; these are identified at low temperature by 1H and 31P NMR spectroscopy.