Silver and Thallium Ion Complexation with Allyloxycalix[4]arenes

Abstract

A series of six calix[4]arene derivatives bearing allyl groups and/or benzyl groups functionalized at the phenolic oxygen atoms were synthesized and their cation-binding abilities for silver(I) and thallium(I) ions were evaluated through solvent extraction experiments. The results showed that both silver(I) and thallium(I) picrates were readily extracted by the tetrasubstituted p-t-butylcalixarene derivatives, while no extraction of sodium or potassium picrates was observed. The high extractability of thallium(I) picrate by these ligands was independent of the functional groups present, but the extraction of silver picrate seemed to be dependent on the conformational rigidity of the calixarene; those locked into the cone conformation showed the highest extractability for silver picrate.