Synthesis, characterization, and crystal structure of Nd(HSeO[sub 3])(SeO[sub 3]) [center dot] 2H[sub 2]O

Journal Article · Fri Dec 31 23:00:00 EST 1993 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1006/jssc.1994.1013· OSTI ID:7284161

Pedro, M de; Castro, A ^[1]; Enjalbert, R; Trombe, J C; Galy, J ^[2]

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1. Instituto de Ciencia de MJateriales de Madrid, Madrid (Spain)
2. Centre d'Elaboration de Materiaux et d'Etudes Structurales, Toulouse (France)

Single crystals of rare-earth hydrated hydrogenselenite Nd(HSeO[sub 3])(SeO[sub 3]) [center dot] 2H[sub 2]O have been obtained by pseudohydrothermal synthesis, using a glass of composition 10SeO[sub 2]:Nd[sub 2]O[sub 3] as precursor. Material characterization was supported by chemical analysis, infrared absorption spectroscopy, and thermal analysis. The latter technique shows the presence of a new rare-earth selenite, Nd[sub 2]Se[sub 4]O[sub 11], as a subproduct of the thermal decomposition. The Nd(HSeO[sub 3])(SeO[sub 3]) [center dot] 2H[sub 2]O compound crystallizes in the orthorhombic system, space group P2[sub 1]2[sub 1]2[sub 1], with unit cell parameters a = 6.699(4) [angstrom], b = 7.101(1) [angstrom] and c = 16.39(2) [angstrom]. The structure has been determined by X-ray single crystal techniques and refined down 6to R = 0.043. It can be described as infinite chains of bicapped trigonal prisms (NdO[sub 7](H[sub 2]O)) sharing edges interconnected by (SeO[sub 3]E) tetrahedra (E lone pair) via corner and edge sharing making a layer (NdSeO[sub 6]) upon which (SeO[sub 2]OHE) groups are grafted, assuming the stability of the network via hydrogen bonding. Free water molecules occupy channels developed along [100]. Particular similarities between the layers (NdSeO[sub 6]) of this structure and the slabs along [010] of the ZrSiO[sub 4] structure are emphasized. The coordination number (CN = 8) of Zr and Nd, bisdisphenoid and bicapped trigonal prisms respectively, can be related by a simple topological distortion. The (SeO[sub 3]E) tetrahedra play a connecting role analogous to that of SiO[sub 4] tetrahedra in the formation of (NdSeO[sub 6]) layers.

• OSTI ID: 7284161
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 108:1; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
HYDRATES
HYDROTHERMAL SYNTHESIS
LATTICE PARAMETERS
MILLER INDICES
NEODYMIUM COMPOUNDS
ORTHORHOMBIC LATTICES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SELENATES
SELENIUM COMPOUNDS
SYNTHESIS
X-RAY DIFFRACTION