The important effect of ligand architecture on the selectivity of metal ion recognition in An( iii )/Ln( iii ) separation with N-donor extractants

The existence of a strong correlation between ligand architecture and metal ion binding selectivity is demonstrated through large differences in the separation efficiencies found in the selective extraction of Am3+ from an acidic mixture of Am3+ and Eu3+ for three new tetrapodal hexadentate ligands containing four 2-pyrazinylmethyl groups attached to three different diamino spacers.