Selective separation of Am(III) from lanthanides(III) by solvent extraction with hydrophobic field of "superweak" anion

The weakly coordinating hydrophobic anion TFPB–, whose surface is covered with a hydrophobic field, gives rise to a selective separation of Am(III) from lanthanides(III) in their solvent extraction even with a hard-donor extractant that shows no selectivity for Am(III) in traditional solvent extraction.