Syntheses and Crystal Structures of [H₃O]⁺/M²⁺ (M = Fe, Zn, Cu, Hg) Salts with [AsF₆]^–

Abstract

The H3OM[AsF6]3 (M = Fe, Zn), H3OMF[AsF6]2 (M = Fe, Cu) and (H3O)2Hg2F[AsF6]5 compounds were prepared by treatment of the corresponding divalent oxide MO (M = Zn, Cu, Hg) with AsF5 in anhydrous HF (aHF) or by reaction between H3OAsF6, FeF2 and AsF5 in aHF. The H3OM[AsF6]3 (M = Fe, Zn) compounds crystallize isotypically to previously known compounds where M is Mn, Co and Ni. The H3OMF[AsF6]2 (M = Fe, Cu) crystal structures consist of one‐dimensional infinite zig‐zag [–M–F–M–] chains. Each M2+ is additionally bridged by two pairs of [AsF6] units with neighbouring M2+ atoms forming columns along the y axis. [H3O]+ cations are placed between the columns. In H3OCuF[AsF6]2 each of the Cu atoms is coordinated by six fluorine atoms {2 × 1.850(2) Å within the [–Cu–F–Cu–] chains and four Cu–F(As) bonds with 2 × 2.067(4) Å and 2 × 2.254(5) Å}. There is a pronounced antiferromagnetic coupling (J/kB = –150 K) within the [–Cu–F–Cu–] chains. In H3OFeF[AsF6]2 the corresponding values are 2 × 1.919(2) Å, 2 × 2.184(3) Å and 2 × 2.208(4) Å. (H3O)2Hg2F[AsF6]5 crystallizes isotypically to previously known (H3O)2Cd2F[SbF6]5. No oxonium–M2+–[AsF6]– salts were observed when M was Ti, V, Cr, Nb, Pd, Ag, Cd, Sn and Pb.

[XeF5]+/Metal and [XeF5]+/Non‐Metal Mixed‐Cation Salts of Hexafluoridoantimonate(V)

“…A similar motif has been observed in AM(AsF 6 ) 3 (A = [H 3 O] + , [NH 4 ] + , O 2 + , NO + , K + , M = Mn; Fe, Co, Ni, Zn) compounds where single charged cations (A) are also found in a tridimensional framework consisting of MF 6 and AsF 6 octahedra (Figures S1 and S2) 14–16. There are two crystallographically independent Cu atoms.…”

Synthesis and crystal structures of HgFAsF6, Hg(HF)2(AsF6)2, Hg(HF)(AsF6)2 and Hg(AsF6)(SO3F)

“…Single crystals of Hg(AsF 6 )(SO 3 F) were obtained unintentionally during the attempt to grow single crystals of (H 3 O) 2 Hg 2 F(AsF 6 ) 5 [15]. The reaction vessels made from FEP or PFA are the most suitable for the work with aHF.…”

“…Single crystals of Hg(AsF 6 )(SO 3 F) were obtained as by-product in one of the attempts to grow single crystals of (H 3 O) 2 Hg 2 F(AsF 6 ) 5 [15]. In that experiment HgO (50 mg) was first dissolved in 5 mL aHF acidified with an excess of AsF 5 , then volatiles were pumped away at 253 K, and finally fresh aHF was added.…”

“…Due to the presence of moisture the second product was (H 3 O) 2 Hg 2 F(AsF 6 ) 5 [15]. Grown crystals were isolated in the same way as for HgFAsF 6 .…”

“…In the following study the successful preparation of HgFAsF 6 and its crystal structure are reported together with the crystal structures of Hg(HF) 2 (AsF 6 ) 2 , Hg (HF)(AsF 6 ) 2 and Hg(AsF 6 )(SO 3 F). 15.5 mm and outer diameter 18.75 mm) equipped with PTFE valves [10] and PTFE coated stirring bars. Prior to their use all reaction vessels were passivated with elemental fluorine (Solvay, Germany).…”