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

The Reactions of Silver, Zirconium, and Hafnium Fluorides with Liquid Ammonia: Syntheses and Crystal Structures of Ag(NH3)2F·2NH3, [M(NH3)4F4]·NH3 (M = Zr, Hf), and (N2H7)F

“…In the redox reaction of blue-violet Ag 3 6 } was identified by single-crystal structure analysis at low temperature, [6] the evolution of nitrogen was observed during the reaction, and NH 4 F was detected by X-ray powder diffraction after pumping off the liquid ammonia at room temperature. However, MF 4 could not be detected in the powder diffraction patterns of the reaction products; it is supposed that MF 4 is produced either as an amorphous material or that ammoniates are formed.…”

“…[6] Now we were able to identify the other products of this complex reaction by X-ray diffraction methods as M(NH 3 ) 4 F 4 ·NH 3 (1, M = Zr; 2, M = Hf) and [NH 4 (NH 3 )]F (3). Compounds 1 and 2 can also be obtained from neat MF 4 (M = Zr, Hf) in liquid NH 3 .…”

“…Recently, we reported the reaction of blue-violet Ag 3 M 2 F 14 (M = Zr, Hf) [11,12] with liquid ammonia and established one product to be [Ag(NH 3 ) 3 (µ-NH 3 )Ag(NH 3 ) 4 ]-MF 6 (M = Zr, Hf) featuring Ag-Ag interactions. [6] Now we were able to identify the other products of this complex reaction by X-ray diffraction methods as M(NH 3 ) 4 F 4 ·NH 3 (1, M = Zr; 2, M = Hf) and [NH 4 (NH 3 )]F (3).…”

“…Compounds 1 and 2 can also be obtained from neat MF 4 (M = Zr, Hf) in liquid NH 3 . Mixtures of AgF or AgF 2 /MF 4 (M = Zr, Hf) in liquid ammonia gave the known product [Ag(NH 3 ) 3 -(µ-NH 3 )Ag(NH 3 ) 4 ]MF 6 (M = Zr, Hf), [6] the pentaammoniates M(NH 3 ) 4 F 4 ·NH 3 (1, M = Zr; 2, M = Hf) and Ag(NH 3 ) 2 F· 2NH 3 (4). When AgF 2 was used as the silver source we thesized either from AgF or AgF 2 in liquid ammonia.…”

“…Their solution chemistry is quite well known in aqueous solutions, hydrofluoric acid, or anhydrous HF. [1][2][3][4][5] We set out to explore the reactions of fluorides with liquid ammonia, which could yield substances like fluoride ammoniates, amine fluorides and amide-or imide fluorides, [6][7][8][9] or even nitride fluorides and nitrides as the final products of these reactions. [10] With the exception of the nitrides, all these classes of compounds are only scarcely known and could feature interesting properties depending on the metal ion.…”