Encapsulation of lanthanide ions in calixarene receptors. A strongly luminescent terbium(3+) complex

Abstract

Complexes in which the Eu³⁺, Tb³⁺, and Gd³⁺ ions are encapsulated in the p-t-butylcalix[4]arene-tetra-acetamide ligand, (1) have been synthesized and their photophysical properties investigated; the Tb³⁺ complex exhibits a high luminescence quantum yield (0.2) and a long luminescence lifetime (1.5 ms) upon ligand excitation in aqueous solution.