ISSN:
0044-2313
Keywords:
Praseodymium
;
Reduced Chlorides
;
Synthesis
;
Crystal Structure
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Na2[Pr4O2]Cl9 and K2[Pr4O2]Cl9, the First Reduced Quaternary Praseodymium Chlorides with Anti-SiS2 Analogous [Pr4/2O] ChainsThe compounds A2[Pr4O2]Cl9 (A = Na, K) are the first reduced quaternary praseodymium chlorides with anti-SiS2 analogous [Pr4/2O] chains. Synthesis took place in the temperature range from 900 to 600°C in silica-jacketed niobium containers from Pr metal, PrCl3, PrOCl and NaCl (KCl) as starting materials. The X-ray structure analysis of a single crystal of Na2[Pr4O2]Cl9 (monoclinic, P21/m (No. 11), Z = 2, a = 812.2(2) pm, b = 1 134.1(2) pm, c = 937.6(2) pm, β = 106.51(2)°, R = 0.048, Rw = 0.037) exhibits trans-edge connected chains of [Pr4/2O] tetrahedra running along [001] which are connected by surrounding common chloride ions forming layers parallel to (001). These layers are connected by further chloride ions to a three-dimensional network. The sodium ions surrounded by a heavily distorted octahedron of chloride ions are placed between the layers. The X-ray structure analysis of a single crystal of the otherwise isotypic K2[Pr4O2]Cl9 (monoclinic, P21/m (No. 11), Z = 2, a = 820.6(2) pm, b = 1 133.2(4) pm, c = 949.2(3) pm, β = 103.94(2)°, R = 0.073, Rw = 0.054) shows that potassium is coordinated by nine chloride ions.
Notes:
Erstmals erhalten wurden reduzierte quaternäre Praseodymchloride mit anti-SiS2-analogen [Pr4/2O]-Ketten vom Typ A2[Pr4O2]Cl9 (A = Na, K). Die Synthese erfolgt im Temperaturbereich von 900 bis 600°C in quarzglasummantelten Niobampullen aus Pr-Metall, PrCl3, PrOCl und NaCl bzw. KCl. Die Röntgenstrukturanalyse an einem Einkristall von Na2[Pr4O2]Cl9 (monoklin, P21/m, Z = 2, a = 812,2(2) pm, b = 1 134,1(2)pm, c = 937,6(2)pm, β = 106,51(2)°, R = 0,048, Rw = 0,037) zeigt, daß die entlang [010] verlaufenden, über gemeinsame transständige Pr—Pr-Kanten zu Ketten verknüpften [Pr4/2O]-Tetraeder in der (001)-Ebene über umgebende, gemeinsame Chloratome zu Schichten verknüpft sind, die ihrerseits über Chloratome zu einer dreidimensionalen Struktur verbunden sind. Zwischen den Schichten befindet sich Na+, stark verzerrt oktaedrisch von Cl- umgeben. Die Röntgenstrukturanalyse an einem Einkristall des ansonsten isotypen K2[Pr4O2]Cl9 (monoklin, P21/m (Nr. 11), Z = 2, a = 820,6(2)pm, b = 1 133,2(4)pm, c = 949,2(3)pm, β = 103,94(2)°, R = 0,073, Rw = 0,054) zeigt, daß K+ dort von 9 Cl- umgeben ist.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19946200114
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