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Title: Gadolinium speciation with Tetradentate, N-donor extractants for minor actinide/lanthanide separation: an XRD, mass spectrometry and EPR study

Conference ·
OSTI ID:22264189
 [1];  [2];  [3]
  1. School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)
  2. School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)
  3. Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

The hydrophobic organic molecules CyMe{sub 4}-BTPhen (1) and CyMe{sub 4}-BTBP (2) have been developed and tuned over many years to be able to separate the trivalent actinides from the trivalent lanthanides (Ln) selectively in bi-phasic solvent extraction processes for the separation of the long-lived radio-toxic minor actinides from spent nuclear fuel. The ability of these N-donor ligands to perform this separation is poorly understood, as is their speciation with the metal ions when extracted into the organic phase. Our previous work has shown Ln{sup 3+} speciation to be largely 1:2 Ln:L in nature with another small molecule, either water or nitrate, occupying a cavity between the tetradentate bound N-donor ligands. The identity of the small molecule changes across the lanthanide series, and here we continue investigations into this speciation. Complexes of these N-donor ligands with Gd{sup 3+} have been synthesised and characterised by X-ray crystallography, mass spectrometry and EPR spectroscopy. We show that the N-donor ligands have no effect on the electronic configuration of Gd{sup 3+} and that the lanthanide contraction with the steric rigidity of the N-donor ligand appears to determine the size of the cavity between the coordinated ligands. This in turn appears to control the identity of the small molecule on the ninth site in the 1:2 Gd:L species. (authors)

Research Organization:
American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
OSTI ID:
22264189
Resource Relation:
Conference: GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads, Salt Lake City, UT (United States), 29 Sep - 3 Oct 2013; Other Information: Country of input: France; 27 refs.; Related Information: In: Proceedings of GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads| 1633 p.
Country of Publication:
United States
Language:
English