Journal article

Publication year: 1996

Pages: 640-648

Journal: Journal of Inorganic and General Chemistry

Volume number: 622

Issue number: 4

ISSN: 0044-2313

DOI Link: https://doi.org/10.1002/zaac.19966220412

Publisher: Wiley

Abstract: 

Colorless [brownblack], hexagonal crystals of Th4Ta18O53 [U4Ta18O53] were obtained by chemical transport. Several mixtures of powders were used as starting materials for chemical transport reactions. Cl-2 or TaCl5/Cl-2 were applied as transport agents in several temperature gradients. The lattice constants are a = 6.2554(5) Angstrom (6.253(1) Angstrom), c = 27.709(5) Angstrom (27.609(6) Angstrom) and Z = 1. Structure determination in the space group P6(3)/mcm (no. 193) let to R1 = 0.0269 (wR2 = 0.0629) (R1 = 0.0295 (wR2 = 0.0674)). Thorium as well as Uran is surrounded by oxygen like an trans-bis-capped octahedron (CN = 8) and Tantalum1 and Tantalum2 like pentagonal-bipyramids (CN = 7). The formula (Th2O3)(2)(Ta3O8)(6) corresponds to the principle of building for the ideal construction. Because of necessarity of valence compensation the number of O-atoms in the real structure is diminished by one.

The Th-O- and U-O-coordination polyhedra are for themselves arranged to o-layers and the Ta1-O- and Ta2-O-bipyramids for each other to p-layers. These layers are edge linked along the c-axes with a sequence of p-p-p-o-p-p-p-o, In fact of this these compounds are the first examples of the new structure type p-p-p-o as a member of a structure-family first described by Jahnberg. The various members differ in the sequence of layers with octahedral (o) and pentagonal-bipyramids (p).

Harvard Citation style: Busch, J. and Gruehn, R. (1996) Synthesis and structure of M(4)Ta(18)O(53) (M=Th, U); The first representatives with a new structure type a la Jahnberg, Zeitschrift für anorganische und allgemeine Chemie = Journal of Inorganic and General Chemistry, 622(4), pp. 640-648. https://doi.org/10.1002/zaac.19966220412

APA Citation style: Busch, J., & Gruehn, R. (1996). Synthesis and structure of M(4)Ta(18)O(53) (M=Th, U); The first representatives with a new structure type a la Jahnberg. Zeitschrift für anorganische und allgemeine Chemie = Journal of Inorganic and General Chemistry. 622(4), 640-648. https://doi.org/10.1002/zaac.19966220412