Syntheses of and metal cation oscillation in ionophoric biscalix[4]arenes

Fumio Ohseto, Seiji Shinkai

研究成果: Contribution to journalArticle査読

10 被引用数 (Scopus)


A series of biscalix[4]arenes (2n) doubly-bridged with oxyethylene chains at the lower rim have been synthesized. As in conventional ionophoric monocalix[4]arene derivatives, these compounds showed ion selectivity towards Na+. The 1H NMR spectroscopic studies established that Na+ and K+ ions complexed with 2n oscillate intramolecularly between two calix[4]arene ionophoric sites. Two coalescence temperatures were found in the temperature-dependent 1H NMR spectra in the presence of these metal cations: the coalescence for the intermolecular metal exchange appears at a high temperature region whereas the coalescence for the intramolecular metal oscillation appears at a low temperature region. These two processes could be discriminated by the difference in the concentration dependence: the intermolecular process is concentration-dependent whereas the intramolecular process is concentration-independent. This is a unique dynamic system in which metal cations jump from one ionophoric site to another ionophoric site in biscalix[4]arenes in the NMR time-scale.

ジャーナルJournal of the Chemical Society, Perkin Transactions 2
出版ステータス出版済み - 1 1 1995

All Science Journal Classification (ASJC) codes

  • 化学 (全般)


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