Structures of sym-(R)dibenzo-16-crown-5-oxyacetic acids and their alkali metal cation binding

To provide insight into the influence of geminal group (R) variation in sym-(R)dibenzo-16-crown-6-oxyacetic acids upon their selectivity in alkali metal cation separations by solvent extraction and liquid membrane transport, studies have been conducted for R=hydrogen and decyl in homogeneous solutions by 1H NMR spectroscopy and titration calorimetry and in the solid state.

Enhanced Na+ selectivity in competitive solvent extraction of alkali metal cations when R=H is replaced by decyl is attributed to increased Na+ binding caused by orientation of the functional sidearm over the crown ether cavity.Figure optionsDownload as PowerPoint slide