Synthesis and anion binding properties of diamide derivatives of p-tert-butylcalix[4]arene

WOS:000274220700007Two 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