The crystal structures of the hydrated alkalimetal-/rare earth(III) chlorides ALnCl{sub 4} {center_dot} 4H{sub 2}O (A = NH{sub 4}, K, Rb, Cs; Ln = La-Sm) and CsLaCl{sub 4} {center_dot} 3H{sub 2}O
- Univ. Gh. Kassel (Germany)
The crystal structures of the compounds RbLaCl{sub 4} {center_dot} 4H{sub 2}O and CsNdCl{sub 4} {center_dot} 4H{sub 2}O have been determined by single crystal X-ray analysis. These compounds precipitate from aqueous solution upon evaporation at 50{degrees}C. RbLaCl{sub 4} {center_dot} 4H{sub 2}O (a = 1140.1 pm, b = 701.8 pm, c = 668.8 pm) and CsNdCl{sub 4} {center_dot} 4H{sub 2}O (a = 1127.1 pm, b = 711.5 pm, c = 678.7 pm) crystallize in the orthorhombic space group P 2{sub 1}2{sub 1}2 with Z = 2. The unit cell parameters of the isotypic compounds KLnCl{sub 4} {center_dot} 4H{sub 2}O (Ln = Ce-Nd), NH{sub 4}LnCl{sub 4} {center_dot} 4H{sub 2}O (Ln = La-Pr), RbLnCl{sub 4} {center_dot} 4H{sub 2}O (Ln = e, Pr) were determined from powder patterns. The structure is composed of layers of edge-bridged polyhedra around both cations. The anionic part of the structure around the rare earth ions consists of the monomeric units [LnCl{sub 4}(H{sub 2}O){sub 4}]{sup {minus}}. The coordination number of both the alkali- and the rare earth-ions is 8, independent of the changes in their ionic radii. Instead of the expected tetrahydrate {open_quotes}CsLaCl{sub 4} {center_dot} 4H{sub 2}O{close_quotes} a trihydrate CsLaCl{sub 4} {center_dot} 3H{sub 2}O was precipitated under the same conditions. This compound crystallizes with the CsUCl{sub 4} {center_dot} 3H{sub 2}O-type structure with the coordination number 9 for La.
- OSTI ID:
- 478918
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 126; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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