Ion Complexation Properties of Calix[6]Arene Derivatives: I. 1,4-Calix[6]Crown-4 Derivatives

Abstract

A series of 1,4-p-tert-butyl-calix6]crown-4 tetraesters, tetraamides, tetraacids with defined conformation have been synthesized, and their complexation properties towards metal ions and alkyl ammonium ions were investigated systematically. It was found that 1,4-p-tert-butyl-calix6]crown-4 tetraethylester (3a) and 1,4-p-tert-butyl-calix6]benzocrown-4 tetramethyl-ester (4b) show high selectivity towards Na⁺, Li⁺, respectively and all of them exhibit high complexation abilities towards Et₂NH₂ ⁺ cation.