Synthesis and Anion Binding Properties of Diamide Derivatives of p-tert-Butylcalix[4]arene

Abstract

Two novel calix[4]arene based anion receptors containing positively charged binding sites in combination with amide groups have been synthesized. Anion binding properties of these receptors towards H₂PO₄ ⁻ and HSO₄ ⁻ ions were studied by ¹H-NMR spectroscopy and the results reflected that receptor 5 selectively recognize H₂PO₄ ⁻ in preference to HSO₄ ⁻ ions. The molar ratio and the association constants of the complexes were determined by using Job plots and a nonlinear least-squares fitting method, respectively.

Keywords:

• Anion recognition
• amide
• calix[4]arene
• tetrabutylammonium salt

Acknowledgement

We thank the Research Foundation of Selcuk University, Konya-Turkey (BAP 09201094) for financial support of this work.

Notes

^aVery weak binding, a stability constant value could not be calculated in this solvent.