Calix[4]tubes: A new class of potassium-selective ionophore

Susan E. Matthews, Phillipe Schmitt, Vitor Felix, Michael G. B. Drew, Paul D. Beer

Research output: Contribution to journalArticlepeer-review

108 Citations (Scopus)

Abstract

A new class of cryptand-like ionophore based on a bis calix[4]arene structure has been developed. These molecules proved highly selective for complexation of potassium over all group I metal cations and barium. A range of symmetric and asymmetric calix[4]tubes featuring either alkyl or phenyl substituents at the upper rim have been synthesized in exceptional yield. Alteration of the calix[4]arene upper rim environment enables fine-tuning of the rate of potassium uptake, which can be evaluated through the conformational change on binding by NMR studies. Selectivity of potassium complexation has been demonstrated using NMR and electrospray mass spectral techniques. Molecular modeling studies, derived from crystallographic data, confirm that the potassium metal cation is complexed via the axial route, passing through the calix[4]arene annulus, and provide evidence for complexation rate and selectivity.
Original languageEnglish
Pages (from-to)1341-1353
Number of pages13
JournalJournal of the American Chemical Society
Volume124
Issue number7
DOIs
Publication statusPublished - 2002

Keywords

  • BINDING
  • CALIX<N>ARENE
  • CAVITY CALIX<4>ARENES
  • CATION-PI INTERACTIONS
  • CALIXARENES
  • CONFORMATION
  • ALKALI-METAL CATIONS
  • EXTRACTION
  • COMPLEXATION
  • ION SELECTIVITY

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