title: Highly efficient separation of actinides from lanthanides by a phenanthroline-derived bis-triazine ligand.
abstract: The synthesis, lanthanide complexation, and solvent extraction of actinide(III) and lanthanide(III) radiotracers from nitric acid solutions by a phenanthroline-derived quadridentate bis-triazine ligand are described. The ligand separates Am(III) and Cm(III) from the lanthanides with remarkably high efficiency, high selectivity, and fast extraction kinetics compared to its 2,2'-bipyridine counterpart. Structures of the 1:2 bis-complexes of the ligand with Eu(III) and Yb(III) were elucidated by X-ray crystallography and force field calculations, respectively. The Eu(III) bis-complex is the first 1:2 bis-complex of a quadridentate bis-triazine ligand to be characterized by crystallography. The faster rates of extraction were verified by kinetics measurements using the rotating membrane cell technique in several diluents. The improved kinetics of metal ion extraction are related to the higher surface activity of the ligand at the phase interface. The improvement in the ligand's properties on replacing the bipyridine unit with a phenanthroline unit far exceeds what was anticipated based on ligand design alone.
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, UK.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Lewis
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Harwood
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hudson
authors.forename: Michael G B
authors.initials: MG
authors.lastname: Drew
authors.forename: Jean F
authors.initials: JF
authors.lastname: Desreux
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Vidick
authors.forename: Nouri
authors.initials: N
authors.lastname: Bouslimani
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Modolo
authors.forename: Andreas
authors.initials: A
authors.lastname: Wilden
authors.forename: Michal
authors.initials: M
authors.lastname: Sypula
authors.forename: Trong-Hung
authors.initials: TH
authors.lastname: Vu
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Simonin