Selective collection of Yb(iii) over La(iii) and Eu(iii) from aqueous solution by bis(tetramethylammonium) salt crystals of p-tert-butylcalix[4]arene-1,3-diphosphonic acid†
Abstract
Unprecedentedly, crystals of the bis(tetramethylammonium) salt of p-tert-butylcalix[4]arene-1,3-diphosphonic acid, having a preorganized hydrophilic guest recognition space sandwiched by hydrophobic host layers, have been prepared for the selective collection of Yb(III) from 0.01 M HCl solution under thermodynamic control.