Lanthanum(III) capture of 18-crown-6 in the cavity of p-sulfonatocalix[4]arene
Abstract
Aqueous solutions of sodium p-sulfonatocalix[4]arene, 18-crown-6 and lanthanum(III) trichloride at pH 2.5 afford the ‘ferris wheel’ type supercation: [{Ln3+⊂(18-crown-6)(OH2)3}∩{(p-sulfonatocalix[4]arene4– + 2H+)}]+ isolated as the chloride with numerous waters of crystallisation.