Stability Constants of Complexes of Alkali Metal Cation with Crown Ether Surfactant Having 18-Crown-6

DOI Web Site Web Site 9 References Open Access
  • Suzuki Maki
    Department of Chemistry, School of Science, Tokai University
  • Fujio Katsuhiko
    Department of Chemistry, School of Science, Tokai University

Bibliographic Information

Other Title
  • 18-crown-6を有するクラウンエーテル界面活性剤とアルカリ金属イオンとの錯体の安定度定数

Search this article

Description

Our previous work showed that the critical micelle concentration (CMC) of dodecanoyloxymethyl-18-crown-6 (C11Φ6) in the presence of 0.22 mol kg-1 alkali metal ion was the highest for K+ having an ionic diameter comparable to the hole size of 18-crown-6 ring and decreased as an ionic diameter of added cation departed from the hole size. In this study, we used octanoyloxymethyl-18-crown-6 (C7Φ6) having the higher CMC than C11Φ6, measured electric conductivities of aqueous C7Φ6 solutions in the presence of alkali metal ions and evaluated stability constants of C7Φ6/alkali metal ion complexes to confirm that the dependence of CMC of crown ether surfactant on the ionic diameter of alkali metal ion is attributed to the selective cation inclusion of its crown ring. As a result, it was found that the stability constant of C7Φ6/alkali metal ion complex was the largest for K+ and decreased as a diameter of cation departed from the hole size as expected. C7Φ6 exhibited the larger stability constant and the lower cation selectivity than 18-crown-6, suggesting that the oxygen atom of carbonyl group in joint part between crown ring and alkyl chain of C7Φ6 participates in the complexation with alkali metal ion.

Journal

References(9)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top