Synthesis and extraction properties of multifunctionalized azocalix[4]arenes containing bipyridyl subunits

Abstract

A series of four azocalixarene derivatives bearing bipyridyl units and additional functional groups such as amide, ester and pyridine at the phenolic oxygen atoms were synthesized. The conformational properties of these ligands were obtained by ¹H NMR spectroscopy. Moreover, extraction properties towards different metals of 1, 2, 4, 5 and 6 using liquid–liquid extraction by atomic absorption spectrometry have been studied and exhibit Ag⁺ selectivity.