Die Ammonolyse von (NH4)2GeF6. Darstellung und Struktur von NH4[Ge(NH3)F5]

Ammonolysis Reaction of (NH₄)₂GeF₆. Synthesis and Structure of NH₄[Ge(NH₃)F₅] (NH₄)₂GeF₆ reacts with ammonia to yield NH₄[Ge(NH₃)F₅] at 280°C. The reaction path was elucidated by in situ time and temperature resolved X-ray powder diffraction. NH₄[Ge(NH₃)F₅] crystallizes isostructurally to NH₄[Si(NH₃)F₅] in the tetragonal space group P4/n (No. 85) with lattice constants a = 619.41(1) pm and c = 724.70(1) pm. The germanium atom is coordinated by five fluorine atoms and the nitrogen atom of the ammonia molecule. The ammonium cation is located on the Wyckoff position (2 a) in P4/n. The crystal structure is stabilized by extensive hydrogen bonding.     

Synthese und Kristallstrukturen von NH4[Si(NH3)F5] und [Si(NH3)2F4]

Synthesis and Crystal Structures of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] Single crystals of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] are obtained by reaction of silicon powder with NH₄HF₂ in sealed Monel ampoules at 400°C. NH₄[Si(NH₃)F₅] crystallizes with the tetragonal space group P4/n (no. 85) with a = 614.91(7) pm, c = 721.01(8) pm, Z = 2. Characteristic for the structure is the anionic octahedron [Si(NH₃)F₅]^?. Si(NH₃)₂F₄ crystallizes with the monoclinic space group P2₁/c (no. 14) with a = 506.9(1) pm, b = 728.0(1) pm, c = 675.9(1), β = 93,21(2)°, Z = 2. Trans-[Si(NH₃)₂F₄] molecules are characteristic for this structure.