Constitutionally asymmetric and chiral [2]pseudorotaxanes

Masumi Asakawa*, Peter R. Ashton, Wayne Hayes, Henk M. Janssen, E. W. Meijer, Stephan Menzer, Dario Pasini, J. Fraser Stoddart, Andrew J P White, David J. Williams

*Corresponding author for this work

Research output: Contribution to journalArticle

44 Scopus citations

Abstract

The self-assembly and characterization of a range of chiral pseudorotaxanes has been explored using chiroptical methods. The syntheses of (i) constitutionally asymmetric acyclic hydroquinone-containing polyethers and (ii) optically active hydroquinone-containing acyclic polyethers, bearing pairs of methyl or isobutyl groups related to each other in a C2-symmetric manner within the polyether backbone, are described. The combination of (i) the tetracationic cyclophane cyclobis(paraquat-p-phenylene) tetrakis(hexafluorophosphate), possessing a π-electron deficient cavity, and (ii) the linear noncentrosymmetric acyclic polyethers produces [2]pseudorotaxanes that have been characterized by 1H NMR, UV/vis and circular dichroism (CD) spectroscopies in solution and by X-ray crystallography in the solid state. The introduction of constitutional asymmetry or chirality gives rise to a number of different geometries for the [2]pseudorotaxanes in both the solution and solid states. In particular, CD-spectroscopic measurements on the optically active [2]pseudorotaxanes have shown that-depending on the positions of the C2 symmetrically related chiral centers in the polyether chains with respect to the hydroquinone rings - the chirality present in the π-electron rich threadlike guest can induce chirality that is associated with the supramolecular structure as a whole, resulting in a chiral charge-transfer transition involving not only the π-donors in the chiral guests but also the π-acceptors in the achiral host.

Original languageEnglish (US)
Pages (from-to)920-931
Number of pages12
JournalJournal of the American Chemical Society
Volume120
Issue number5
DOIs
StatePublished - Feb 11 1998

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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    Asakawa, M., Ashton, P. R., Hayes, W., Janssen, H. M., Meijer, E. W., Menzer, S., Pasini, D., Stoddart, J. F., White, A. J. P., & Williams, D. J. (1998). Constitutionally asymmetric and chiral [2]pseudorotaxanes. Journal of the American Chemical Society, 120(5), 920-931. https://doi.org/10.1021/ja970018i