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Cs 5 [Na{W 4 N 10 }]: The first framework nitridotungstate(VI)
Author(s) -
Niewa R.,
Jacobs H.
Publication year - 1996
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.19966220522
Subject(s) - alkali metal , tungsten , caesium , crystallography , sodium , chemistry , ammonia , nitride , molar ratio , nitrogen , inorganic chemistry , analytical chemistry (journal) , nuclear chemistry , organic chemistry , layer (electronics) , catalysis
Cs 5 [Na{W 4 N 10 }] was prepared from a mixture of NaNH 2 , CsNH 2 and tungsten powder (molar ration 1 : 10 : 4) at 700°C in autoclaves. After the reaction is finished the nitride is embedded in an alkali metal matrix. Dark red crystals were isolated by washing out the alkali metal with liquid ammonia at room temperature. The structure of Cs 5 [Na{W 4 N 10 }] was solved by X‐ray single crystal data: I4 1 (No. 80), Z = 4, a = 13.926(3) Å, c = 8.723(3) Å, Z(F o 2 ) ≥ 3σ(F o 2 ) = 1535, Z(Variables) = 63, R/R w = 0.040/0.052. The compound is highly sensitive against moisture giving oxotungstates and ammonia. It contains a framework of tetrahedra ∞ 3 [WNN 3/2 1.5− ]. Sodium shares four terminal nitrogen ligands. Including sodium a distorted, β‐cristobalite type arrangement ∞ 3 [Na{W 4 N 10 } 5− ] results. It contains caesium in all interstices formed by twelve nitrogen ligands in so‐called Friauf polyhedra.