Synthesis of calix[4]crowns containing soft donor atoms and a study of their metal–cation binding properties: highly selective receptors for Cu²⁺

Abstract

Two new calix[4]arenethiacrown derivatives 1 and 2 in the cone conformation were synthesized by two different pathways in good yield. Their complexation properties toward alkali, alkaline earth and transition metal cations were studied in acetonitrile at 298.15 K using a conductometric titration technique. The selectivity for Cu2+ over other cations with these novel ligands was excellent.