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

Abstract

(NH4)2GeF6 reagiert mit Ammoniak bei 280°C zu NH4[Ge(NH3)F5]. Der Reaktionsverlauf wurde in situ mit Hilfe der zeit‐ und temperaturaufgelösten Röntgenpulverdiffraktometrie verfolgt. Das so dargestellte NH4[Ge(NH3)F5] kristallisiert isostrukturell mit NH4[Si(NH3)F5] in der tetragonalen Raumgruppe P4/n (Nr. 85) mit den Gitterkonstanten a = 619,41(1) pm und c = 724,70(1) pm. Dabei ist das Germaniumatom verzerrt oktaedrisch von fünf Fluoratomen und dem Stickstoffatom des Ammoniakmoleküls koordiniert. Das Ammoniumion liegt auf der Tetraederpunktlage (2 a) in P4/n. Die Verbindung wird durch Wasserstoffbrückenbindungen stabilisiert.

Synthesis and Characterization of Ge(II), Sn(II), and Pb(II) Monoamides with −NH2 Ligands

“…Ammine complexes are well-known for most transition metals. For main group elements, however, stable complexes are most numerous for group 13 and earlier groups, although a number of ammine complexes of silicon, germanium, and tin 29 have been structurally characterized. Nonetheless, these structures concern tetravalent species, and only one divalent ammine derivative of these elements, the species ( R ) -[Ge{O 2 C 20 H 10 (SiMe 2 Ph) 2 -3,3‘}(NH 3 )], has been characterized .…”

Understanding the “Molten Salt” Synthesis of MAPbI3 – Characterization of New Lead(II)‐Ammine Complexes as Intermediates

“…[25,26] SiF 4 (NH 3 ) 2 is of interest as a representative of a Lewis acid/base adduct, but according to our knowledge, this is one of the very few examples of a structurally characterised species. Furthermore, all representatives known up to now are flourides with fluorine as the majority ligand (SiF 5 (NH 3 )(NH 4 ), [25] GeF 5 (NH 3 )[NH 4 ], [27] N 2 H 5 Sn 2 F 5 , [28] N 2 H 5 Sn 3 F 7 , [29] Sn(NH 3 ) 2 F 4 [30] ). Nevertheless, there are also some very old reports for the heavier halides on the interaction of ammonia with lead(II) halides.…”

Crystal Structures of Ag2ZrF6·8NH3 and Ag2HfF6·8NH3 and Their Synthesis by the “Reactive Fluoride Route” in Liquid Ammonia

“…[6] Several representatives have been characterized structurally by Meyer and co-workers who used NH 4 F, NH 4 HF 2 , or N 2 H 6 F 2 to oxidize the respective metals and half-metals in sealed metal ampoules at higher temperatures to produce for example Zr(NH 3 )F 4 and Hf(NH 3 )F 4 . [8,9] Others used supercritical ammonia at 400°C for the preparation of AlF 3 (NH 3 ) 2 and InF 2 (NH 2 )(NH 3 ) [10] or ammonolysis at higher temperatures with gaseous ammonia (NH 4 [Ge(NH 3 )F 5 ], [11] Sn(NH 2 ) 2 -F 2 [12] ). Our method is based on the use of metal fluorides with the metal in an "unusual" oxidation state -here Ag IIin order to bypass the high lattice energy and allow dissolution in liquid ammonia.…”