Synthesis and Metal Ion Recognition Properties of a Novel Chiral Calix[4](azoxa)crown-7

Abstract

A novel chiral calix[4](azoxa)crown-7 (9) has been synthesized and its metal ion recognition properties investigated. The starting reagents, chiral diamine 5 and calix[4]arene diacid chloride derivative 8, were prepared according to literature methods. ¹H and ¹³C NMR data show that 9 exists in a cone conformation. In liquid–liquid extraction experiments, 9 exhibits selectivity for Li⁺ among the other alkali metals and a good extraction ability for transition metal cations, suggesting its potential use in different fields, such as a sensor for ions as well as for chiral molecules.

Keywords:

• Calix[4]arene
• Chirality
• Azoxacrown ether
• Solvent extraction

Acknowledgements

We thank the Research Foundation of Selcuk University, Konya, Turkey (SUAF-EF-99/001) for financial support.