Synthese und Kristallstruktur eines Natrium-tetraoxonitridowolframats(VI), Na5WO4N

Synthesis and Crystal Structure of Sodium Tetraoxo Nitrido Tungstate(VI), Na₅WO₄N Colourless crystals of Na₅WO₄N are obtained besides Na₄WO₂N₂ [1] by the reaction of WO₃ with NaNH₂ (15:1) at 350°C ≥ T ≥ 750°C in autoclaves to prevent early decomposition of sodium amide. X-ray single crystal investigations are characterized by the following data:

• Na₅WO₄N: Cmc2₁ (No. 36), Z = 4
• a = 9.873(2) Å, b = 5.769(1) Å, c = 10.648(2) Å
• Z(F)≥ 3σ(F) = 2182, Z(Var.) = 55, R/R_w = 0.029/0.039

The structure contains the tetragonal pyramidal ion WO₄N^5? with nitrogen at the apex connected via Na⁺ ions irregularly coordinated by one nitrogen and four oxygen atoms of different anions.