title: An Operationally Simple Method for Separating the Rare-Earth Elements Neodymium and Dysprosium.
abstract: Rare-earth metals are critical components of electronic materials and permanent magnets. Recycling of consumer materials is a promising new source of rare earths. To incentivize recycling there is a clear need for simple methods for targeted separations of mixtures of rare-earth metal salts. Metal complexes of a tripodal nitroxide ligand [{(2-(t) BuNO)C6 H4 CH2 }3 N](3-) (TriNOx(3-) ), feature a size-sensitive aperture formed of its three η(2) -(N,O) ligand arms. Exposure of metal cations in the aperture induces a self-associative equilibrium comprising [M(TriNOx)thf]/ [M(TriNOx)]2 (M=rare-earth metal). Differences in the equilibrium constants (Keq ) for early and late metals enables simple Nd/Dy separations through leaching with a separation ratio SNd/Dy =359.
authors.affiliation: Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Philadelphia, PA 19104 (USA).
authors.forename: Justin A
authors.initials: JA
authors.lastname: Bogart
authors.affiliation: Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Philadelphia, PA 19104 (USA).
authors.forename: Connor A
authors.initials: CA
authors.lastname: Lippincott
authors.affiliation: Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Philadelphia, PA 19104 (USA).
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Carroll
authors.affiliation: Department of Chemistry, University of Pennsylvania, 231 S. 34th St., Philadelphia, PA 19104 (USA). schelter@sas.upenn.edu.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Schelter
keywords: N,O ligands; magnet recycling; metal separation; neodymium; rare earths