Darstellung und Strukturbestimmung zweier Salze der Trimetaphosphimsäure,K3(PO2NH)3 und Rb3(PO2NH)3

Synthesis and Structure Determination of Two Salts of the Trimetaphosphimic Acid, K₃(PO₂NH)₃ and Rb₃(PO₂NH)₃ The reaction between P₃N₅ and the corresponding alkalimetal hydroxide monohydrate under ammonothermal conditions (6 kbar, 450 °C after 10 d) in autoclaves leads to the salts of the trimetaphosphimic acid K₃(PO₂NH)₃ resp. Rb₃(PO₂NH)₃. The structure of K₃(PO₂NH)₃ was solved by single crystals X-ray methods. The isotypic structure of Rb₃(PO₂NH)₃ was solved by X-ray powder diffraction methods. K₃(PO₂NH)₃: R3 (No. 148), a = 12.615(3) Å, c = 10.224(2) Å, Z = 6, R₁/wR₂ = 0.0276/0.0726, N(F > 2σ(F)) = 769, N(Var.) = 51.Rb₃(PO₂NH)₃: R3 (No. 148), a = 12.9971(5) Å, c = 10.5485(5), Z = 6, R_Bragg(F) = 0.0626, 289 reflections. K₃(PO₂NH)₃ and Rb₃(PO₂NH)₃ contain six-membered rings P₃N₃ substituted by oxygen which are connected to double molecules by N–H … O bridge bonds. These twinmolecules are stacked in columns which form the motive of close packed rods. K⁺ resp. Rb⁺ are between these columns. They are coordinated by 6 O which belong to 5 different rings.