A first report on ternary complex formation between p-sulfonatothiacalix[4] arene, tetramethylammonium ion and gadolinium (III) ion in aqueous solutions

Abstract

The three ternary Gd3+-p-sulfonatothiacalix[4]arene- tetramethylammonium complexes formed in aqueous solutions at pH 4-10 have 1:1:1 stoichiometry and enhanced stability due to Gd3+ coordination via phenolate groups at the lower rim and tetramethylammonium included into the cavity through the upper rim. © 2005 Elsevier B.V. All rights reserved.