New series of niobium oxychlorides, M{sub 2}RENb{sub 6}Cl{sub 15}O{sub 3} (M = monovalent cation, RE = rare earth) and M{sub 2}UNb{sub 6}Cl{sub 15}O{sub 3}, the crystal structure of Cs{sub 2}UNb{sub 6}Cl{sub 15}O{sub 3}

Journal Article · Wed Jan 01 04:00:00 EST 1997 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(96)00171-7· OSTI ID:455222

Cordier, S; Perrin, C; Sergent, M ^[1]

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1. URA CNRS, Rennes (France). Lab. de Chimie du Solide et Inorganique Moleculaire

The new M{sub 2}RENb{sub 6}Cl{sub 15}O{sub 3} (M = monovalent cation; RE = rare earth) and M{sub 2}UNb{sub 6}Cl{sub 15}O{sub 3} oxychlorides, isotypic with the corresponding tantalum oxybromides (Cs{sub 2}LaTa{sub 6}Br{sub 15}O{sub 3} structure-type: trigonal, P{bar 3}1c), have been isolated. The crystal structure of Cs{sub 2}UNb{sub 6}Cl{sub 15}O{sub 3} (a = 9.2080(7) (angstrom), c = 17.095(3) {angstrom}) has been refined from single crystal X-ray diffraction data. It is based on [(Nb{sub 6}Cl{sub 9}{sup i}O{sub 3}{sup i})Cl{sub 6}{sup a}]{sup 5{minus}} units centered on the threefold axis at z = 1/4 and 3/4. Uranium is 9-coordinated by three O{sup i} and six Cl{sup a} belonging to six adjacent units. The structural results indicate that the uranium should be in the trivalent state, leading to 14 valence electrons per Nb{sub 6} cluster. Magnetic measurements do not indicate any interaction between the uranium atoms in this compound, but great crystal field effects.

• OSTI ID: 455222
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 1 Vol. 32; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CESIUM COMPOUNDS
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
LATTICE PARAMETERS
MAGNETIC PROPERTIES
MONOCRYSTALS
NIOBIUM COMPOUNDS
OXYCHLORIDES
RARE EARTH COMPOUNDS
URANIUM COMPOUNDS
X-RAY DIFFRACTION