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

Abstract

By reaction of the tetrafluorides MF4 or the ternary silver fluorides Ag3M2F14 (M = Zr, Hf) with dry liquid ammonia at –40 °C, the pentaammoniates [M(NH3)4F4]·NH3 (1, M = Zr; 2, M = Hf) were obtained, and these compounds represent hitherto unknown molecular inorganic Zr and Hf compounds that simultaneously bear nitrogen and fluorine ligands. The compounds crystallize isotypically in the shape of colorless needles in the tetragonal space group P4/ncc. As a further product [NH4(NH3)]F (3) was isolated in the form of colorless cubes in the orthorhombic space group Pca21. It is the first ammoniate of ammonium fluoride. Ag(NH3)2F·2NH3 (4) can be synthesized either from AgF or AgF2 in liquid ammonia. The compound crystallizes merohedrally twinned in the orthorhombic space group Pnna and represents the first crystallographically characterized diamine silver(I) halide complex. In the latter two structures, free fluoride anions are encountered. The ammoniates are highly temperature‐sensitive and decompose at temperatures above –30 °C due to their ammonia pressure.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

UF6 and UF4 in Liquid Ammonia: [UF7(NH3)]3− and [UF4(NH3)4]

“…An X-ray powder pattern of this dry reaction mixture shows no reflections for UF 4 , NH 4 F, N 2 H 7 F, [16] or known ammonium fluorouranates. However, decrepitation of the crystals due to the loss of ammonia naturally results in a phase of low crystallinity.…”

“…Because the N···N distance between one of the ammonium ions and the ammonia of crystallization molecule is quite short at only 2.882(6) and with a N À H···N hydrogen bond length of 1.99(8) , the entity might better be described as a diamminehydrogen(1+) cation, N 2 H 7 + , which is quite well known from the literature. [16,[19][20][21][22][23] Table 3. The molecules are interconnected by NÀ H···F hydrogen bonds.…”

Dissolving the insoluble: CdF2 and moist ammonia form cadmium(II) difluoride monohydrate—synthesis and crystal structure of [Cd(NH3)6]F2·H2O

“…explored [17][18][19][20][21][22][23][24][25][26]. The N-HÁÁÁF hydrogen bonds in compound 1 show donorÁÁÁacceptor (DÁÁÁA) distances between 2.900(2) and 3.135(3) Å , and the DÁÁÁA distances for the N-HÁÁÁO hydrogen bonds are 3.056(2) and 3.262(3) Å ( Table 5).…”

Reactions of Beryllium Halides in Liquid Ammonia: The Tetraammineberyllium Cation [Be(NH3)4]2+, its Hydrolysis Products, and the Action of Be2+ as a Fluoride‐Ion Acceptor

“…4 F, were also identified. [84] Alternatively, a flame-dried reaction vessel was charged with UF 4 (50.0 mg, 0,16 mmol), BeF 2 (22.5 mg, 0.48 mmol), and liquid ammonia (ca. 10 mL).…”

“…It contains the monoammineammonium cation [NH 4 A C H T U N G T R E N N U N G (NH 3 + cation compare well with those in [N 2 H 7 ]F and other reference compounds. [84][85][86][87][88] All other hydrogen atoms of the cation are also involved in NÀH···F hydrogen bonding. For a projection of the cation, see Figure 6 a; details of the hydrogen bonding are provided in its caption.…”