Highly efficient separation of actinides from lanthanides by a phenanthroline-derived bis-triazine ligand

The synthesis, lanthanide complexation, and solvent ex- traction 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, respec-tively. 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

Etude cristallographique, par RPE et spectroscopie optique du (15-couronne-5 ether) diaquo dichloro methano cuivre (II)

La structure cristallographique de C10H20O5 • CuCl2(H2O)2CH3OH a été déterminée à partir des données diffractométriques de RX. Le composé est monoclinique (groupe spatial Pn) avec a = 8,626(6), b = 13,631 (4). c = 16,155(9) Å, β = 104,99(5)°, Z = 4 (deux molécules indépendantes). La structure cristalline est formée d’un assemblage de chaînes infinies dans lesquelles les chromophores CuCl2(H2O)2CH3OH alternent avec les cycles C10H20O5. Des ponts hydrogène lient les chromophores aux éthers couronne. La géométrie de coordination de l’ion Cu (II) est celle d’une pyramide à base carrée déformée. Les paramètres RPE ont été mesurés sur monocristal à température ambiante. On trouve, comme valeurs moléculaires de g : gx = 2,090 ; gy = 2,053 et gz = 2,343. Ces valeurs ainsi que les bandes d’absorption optiques ont pu être reproduites au moyen d’un modèle A.O.M. avec les valeurs suivantes des paramètres : [math] = – 5300 cm–1 ; [math] ~ 0,1 [math] ; (eσ)Cl = – 4900 cm–1 ; [math] = 0,4 ; kx = ky = 0,8 ; kz = 0,77

Investigation of the crystalline and electronic structures of a 4:3:3:4 layered Bi-Ca-Sr-Cu oxide

Semiconducting samples of a Bi-Ca-Sr-Cu oxide, having a nominal composition 4:3:3:4, were prepared by melting high-purity oxides of the various elements. Superconducting samples were obtained by annealing the semiconducting samples at a temperature close to the melting temperature. Electric resistivity measurements indicated the presence of two superconducting phases, one with the onset temperature at about 110 K, the other with a significantly lower onset temperature. The presence of this second phase is proven by the X-ray powder diffraction patterns. The crystalline structures of both the semiconductor and superconductor samples have almost equal lattice parameters and are orthorhombic, but belong to different space groups: Fmmm and Bbmm, respectively. No significant amount of the 110 K superconducting phase was present in the diffraction pattern of the superconducting compound. XPS and XANES data on the Ca atom indicate that a different electronic state of Ca is present in the superconducting compound, which still contains an appreciable amount of the semiconducting phase

Transmutation of Technetium and Iodine-Irradiation Tests in the Frame of the EFTTRA Cooperation.

Abstract not availableJRC.(IAM)-Institute For Advanced Material