Binding properties of neutral diamide ligands for alkaline-earth cations.

The complexation of a series of aromatic and alicyclic N,N,N',N'-tetra-n-propyl amides of 1,2-ethylenedioxydiacetic acids with group IIA metal-ion bromides in anhydrous methanol was investigated by ultraviolet absorption spectroscopy. These synthetic ligands were previously found to show selectivity toward divalent over monovalent cations with respect to extraction of ions into bulk organic phase (Borowitz, I.J.