Strapped calix[4]pyrrole as a lithium salts selective receptor through separated ion-pair binding

Abstract

A triazole-bearing strapped calix[4]pyrrole (1) was synthesized as a lithium salt selective ion pair receptor. ¹H NMR spectral studies and X-ray crystallography showed that the capture of LiCl by 1 occurs via separated ion pair binding. Furthermore, lithium salts extracted by 1 could be solidified in the form of Li₂CO₃ through CO₂ or K₂CO₃ treatment.