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

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.