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Title: U(IV)/Ln(III) mixed site in polymetallic oxalato complexes. Part III: Structure of Na[Yb(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O)].3H{sub 2}O and the derived quadratic series (NH{sub 4}{sup +}){sub 1-x}[Ln{sub 1-x}U{sub x} (C{sub 2}O{sub 4}){sub 2}(H{sub 2}O)].(3+x) H{sub 2}O, Ln=Y, Pr-Sm, Gd, Tb

Journal Article · · Journal of Solid State Chemistry
 [1];  [1];  [1];  [1];  [2]
  1. Laboratoire de Cristallochimie et Physicochimie du Solide, UMR CNRS 8012, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d'Ascq Cedex (France)
  2. Laboratoire de Chimie des Actinides, CEA VALRHO/DRCP/SCPS, Bat 399 BP 17171, 30208 Bagnols sur Ceze Cedex (France)

Single crystals of a new sodium ytterbium oxalate Na[Yb(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O)].3H{sub 2}O (1) and six mixed lanthanide (III)-uranium (IV) oxalates (NH{sub 4}{sup +}){sub 1-x}[Ln{sub 1-x}U{sub x} (C{sub 2}O{sub 4}){sub 2}(H{sub 2}O)].(3+x) H{sub 2}O, Ln=Y, x=0.47 (2), Ln=Pr, x=0.42 (3), Ln=Nd, x=0.60 (4), Ln=Sm, x=0.55 (5), Ln=Gd, x=0.25 (6) and Ln=Tb, x=0.52 (7) have been grown using slow diffusion through silica gels. The crystal structures of all the compounds have been determined by single-crystal X-ray diffraction. For compound 1 the symmetry is monoclinic, space group Pc, cell dimensions a=8.559(2)A, b=8.564(2)A, c=14.938(3)A, {beta}=103.062(3), Z=4. The structure of 1 is isotypic with Na[Y(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O)].3H{sub 2}O and consists of layers formed by four-membered rings of Yb connected through oxalate ions. The ytterbium atom is nine-coordinated by oxygen from four bis-bidentate oxalate ligands and one water molecule which alternate up and down the layer. Na{sup +} ions and supplementary water molecules are located between the layers. The six mixed lanthanide (III)-uranium (IV) oxalates, 2-7, are isotypic, the symmetry is tetragonal, space group P4/n, the unit cell parameters are in the range 8.7239(12)-8.9116(6) and 7.854(2)-7.9487(9)A for a and c, respectively, Z=2. The structure of the six compounds is built from the same two-dimensional arrangement of alternating metallic and oxalate ions forming four-membered rings. The layers are similar to that observed in 1 and the mixed Ln(III)/U(IV) oxalate layers are obtained by partial substitution of Ln(III) by U(IV) in a nine-coorted site, the charge surplus being compensated by removal of monovalent cations in the interlayer space. The ammonium ions and the water molecules are disordered in the same crystallographic site. Thus these compounds form the third series of mixed lanthanide (III)-uranium (IV) oxalates, the tetragonal one, that completes the two others previously reported, the hexagonal and the triclinic series.

OSTI ID:
20900942
Journal Information:
Journal of Solid State Chemistry, Vol. 179, Issue 12; Other Information: DOI: 10.1016/j.jssc.2006.09.007; PII: S0022-4596(06)00515-9; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
Country of Publication:
United States
Language:
English