Strukturuntersuchungen an Usoviten: Ba2CaMIIV2F14 (MIII = Mn,Fe), Ba2CaMnFe2F14 und Ba2CaCuM2IIIF14 (MIII = Mn,Fe, Ga)

Structural Studies with Usovites: Ba₂CaM^IIV₂F₁₄ (M^III = Mn, Fe), Ba₂CaMnFe₂F₁₄ and Ba₂CaCuM₂^IIIF₁₄ (M^III = Mn, Fe, Ga). Single crystals of six compounds Ba₂CaM^IIM₂^IIIF₁₄ were prepared to refine their usovite type structure (space group C2/c, Z = 4) using X‐ray diffractometer data. The cell parameters of the phases studied with M^IIM₂^III= MnV₂, FeV₂, CuMn₂, MnFe₂, CuFe₂ und CuGa₂ are within the range 1374≤a/pm≤1384, 534≤b/pm≤542, 1474≤c/pm≤1510, 91, 3≤ß/°≤93, 2. The atoms Ca and M^II are incompletely ordered on the 8‐ and 6‐coordinated positions, 4e and 4b, respectively. In the case of Ba₂CaFeV₂F₁₄ and Ba₂CaCuGa₂F₁₄ there is reciprocal substitution (x≈0, 1): (Ca_1‐xM_x^II) (4e) and (M_1‐x^IICa_x) (4b). In the case of the other usovites Ca‐enriched phases Ba₂Ca(M_1‐y^IICa_y)M₂^IIIF₁₄ occured (up to y≈0, 35), exhibiting partial substitution at the octahedral position (4b) only, showing a corresponding increase in M^II‐F distances. The distortion of [M^IIF₆] and [M^IIIF₆] octahedra within the structure is considerably enhanced on replacement by Cu^II and Mn^III. The results of powder magnetic susceptibility measurements of Ba₂CaMnV₂F₁₄ and Ba₂CaFeV₂F₁₄ (T_N≈7K) are reported.     

Gitterkonstanten und Ionenradien für Pyrochlore CsMIIMIIIF6

Lattice Constants and Ionic Radii of Pyrochlores CsM^IIM^IIIF₆ From observed lattice constants a₀ of 30 cubic pyrochlores CsM^IIM^IIIF₆ (M^II = Mg, Ni, Cu, Zn, Co, Mn; M^III = Ga, Cr, Fe, V, Ti) balanced values a_c were calculated, which deviate in average less than 0.1% from the observed ones. Radii r_c of the M(II) and M(III) ions are evaluated from the balanced values a_c by means of an empiric equation; they reproduce the lattice constants a₀ equally well. By analogy derived radii r_II and r_III from additional pyrochlores CsM^IIM^IIIF₆ are given and discussed in comparison with tabulated radii and observed M? F distances.     

Die Kristallstrukturen der Vanadium-Weberite Na2MIIVIIIF7 (MII  Mn,Ni, Cu) und von NaVF4

The Crystal Structures of the Vanadium Weberites Na₂M^IIV^IIIF₇ (M^II ? Mn, Ni, Cu) and of NaVF₄ At single crystals of the vanadium(III) compounds NaVF₄ (a = 790.1, b = 531.7, c = 754.0 pm, β = 101.7°; P2₁/c, Z = 4), Na₂NiVF₇ (a = 726.0, b = 1031.9, c = 744.6 pm; Imma, Z = 4) and Na₂CuVF₇ (a = 717.6, b = 1043.5, c = 754.6 pm; Pmnb, Z = 4) X-ray structure determinations were performed, at Na₂MnVF₇ (a = 746.7, c = 1821.6 pm; P3₂21, Z = 6) a new refinement. NaVF₄ crystallizes in the layer structure type of NaNbO₂F₂. The fluorides Na₂M^IIVF₇ represent new orthorhombic (M^II ? Ni; Cu) resp. trigonal (M^II ? Mn) weberites. The average distances within the [VF₆] octahedra of the four compounds are in good agreement with each other and with data of related fluorides (V? F: 193.3 pm). The differences between mean bond lengths of terminal and bridging F ligands are 5% in NaVF₄, but less than 1% in the weberites. Details and data for comparison are discussed.     

Die Kristallstruktur der hydratisierten Cyanokomplexe NMe4MnII[(Mn, Cr)III(CN)6] · 3 H2O und NMe4Cd[MIII(CN)6] · 3 H2O (MIII = Fe,Co): Verwandte des Berliner Blaus

The Crystal Structure of the Hydrated Cyano Complexes NMe₄Mn^II[(Mn, Cr)^III(CN)₆] · 3 H₂O and NMe₄Cd[M^III(CN)₆] · 3 H₂O (M^III = Fe, Co): Compounds Related to Prussian Blue The crystal structures of the isotypic tetragonal compounds (space group I4, Z = 10) NMe₄Mn^II · [(Mn, Cr)^III(CN)₆] · 3 H₂O (a = 1653.2(4), c = 1728.8(6) pm), NMe₄Cd[Fe(CN)₆] · 3 H₂O (a = 1642.7(1), c = 1733.1(1) pm) and NMe₄Cd[Co(CN)₆] · 3 H₂O (a = 1632.1(2), c = 1722.4(3) pm) were determined by X‐rays. They exhibit ⊥ c cyanobridged layers of octahedra [M^III(CN)₆] and [M^IIN₄(OH₂)₂], which punctually are interconnected also || c to yield altogether a spaceous framework. The M^II atoms at the positions linking into the third dimension are only five‐coordinated and form square pyramids [M^IIN₅] with angles N–M^II–N near 104° and distances of Mn–N: 1 × 214, 4 × 219 pm; Cd–N: 1 × 220 resp. 222, 4 × 226 resp. 228 pm. Further details and structural relations within the family of Prussian Blue are reported and discussed.     

Tetragonale Fluorperowskite AM0,75 ▭ 0,25F3 mit Kationendefizit: K4MnIIMn2IIIF12 und Ba2Cs2Cu3F12

Tetragonal Fluoroperovskites AM_0,75 □ _0,25F₃ Deficient in Cations: K₄Mn^IIM₂^IIIF₁₂ and Ba₂Cs₂Cu₃F₁₂ By heating 2KMnF₃ + K₂MnF₆ and BaF₂, CsF + CuF₂ respectively, the isostructural tetragonal compounds K₄Mn₃F₁₂ (a = 832.2, c = 1643.0 pm) and Ba₂Cs₂Cu₃F₁₂ (a = 854.1, c = 1704.1 pm) were prepared. They crystallize in a cation-deficient perovskite structure exhibiting ordering of octahedral vacancies. Single crystal structures determinations in the space group I4₁/amd, Z = 4, yielded the following average distances within the octahedra, which are Jahn-Teller distorted for Mn^III and Cu^II:Mn^II? F = 208.3 pm, Mn^III? F = 4 × 183.0/2 × 209.7 pm; Cu? F = 190.7/227.1 and 190.6/236.4 pm, respectively. The results are discussed in comparison with related compounds.     

Struktur‐ und magnetochemische Untersuchungen an Ba5Mn3F19 und verwandten Verbindungen AII5MIII3F19

Structural and Magnetochemical Studies of Ba₅Mn₃F₁₉ and Related Compounds A^II₅M^III₃F₁₉ Single crystal structure determinations by X‐ray methods were performed at the following compounds, crystallizing tetragonally body‐centred (Z = 4): Sr₅V₃F₁₉ (a = 1423.4(2), c = 728.9(1) pm), Sr₅Cr₃F₁₉ (a = 1423.5(2), c = 728.1(1) pm), Ba₅Mn₃F₁₉ (a = 1468.9(1), c = 770.3(1) pm, Ba₅Fe₃F₁₉ (a = 1483.5(1), c = 766.7(1) pm), and Ba₅Ga₃F₁₉ (a = 1466.0(2), c = 760.1(2) pm). Only Ba₅Mn₃F₁₉ was refined in space group I4cm (mean distances for elongated octahedra Mn1–F: 185/207 pm equatorial/axial; for compressed octahedra Mn2–F: 199/182 pm), the remaining compounds in space group I4/m. In all cases the octahedral ligand spheres of the M1 atoms showed disorder, the [M1F₆] octahedra being connected into chains in one part of the compounds and into dimers in the other. The magnetic properties of the V, Cr and Mn compounds named above and of Pb₅Mn₃F₁₉ and Sr₅Fe₃F₁₉ as well were studied; the results are discussed in context with the in part problematic structures.     

Übergangsmetallkomplexe der Pyrazin-2,6-dicarbonsäure und der Pyridin-2,6-dicarbonsäure: Synthesen und Elektrochemie. Die Kristallstruktur von NH4[RuCl2(dipicH)2]

Transition Metal Complexes Containing the Ligands Pyrazine-2, 6-dicarboxylate and Pyridine-2, 6-dicarboxylate: Syntheses and Electrochemistry. Crystal Structure of NH₄[RuCl₂(dipicH)₂] The coordination chemistry of the tridentate ligand pyrazine-2, 6-dicarboxylate (pyraz-2,6 = L) with transition metals in aqueous solution has been investigated. The reaction of the ligand with metal aqua ions (1:1) affords insoluble precipitates [M^IIL(OH₂)₂] (M = Mn, Fe, Co, Ni, Cu, Zn, Cd). [TiOL(OH₂)₂], [VOL(H₂O)₂] and [UO₂L(H₂O)] were also prepared. [M^IIIL₂]^? complexes (M^III ? Fe^III, Co^III) were isolated as NH₄⁺ and P(C₆H₅)₄⁺ salts; they are strong one electron oxidants (E_1/2 = +0.602 V and +0.795 V vs. NHE, respectively). Redox potentials of analogous complexes containing pyridine- 2, 6-dicarboxylate (L′) ligands have been determined by cyclic voltammetry: [ML′₂]^1-/2?: M = V^III: -0.591 V; Cr^III: -0.712 V. It is shown that pymzine-2,6-dicarboxylate as compared to pyridine-2,6-dicarboxylate stabilizes metal complexes in low oxidation states (+II). The reaction of RuCl₃ · nH₂O with pyridine-2,6-dicarboxylic acid in aqueous solution affords the yellow-green anion [RuCl₂(L′H)₂]^?. The crystal structure of NH₄[RuCl₂(L′H)₂] has been determined. It crystallizes in the monoclinic space group P2₁/c with a = 8.812(2) Å b = 10.551(2) Å, c = 10.068(2) Å, β = 110.03(6)°, Z = 2; 2507 independent reflections; R = 0.032. The ruthenium centers are in an octahedral environment of two Cl^? ligands (trans) and two bidentate pyridine-2, 6-hydrogendicarboxylate ligands which possess each one protonated, uncoordinated carboxylic group.     

Magnetic Anisotropy in a Family of Experimentally Synthesized and Theoretically Modeled M′6M8(CN24) Systems

A theoretical density functional study of the magnetic coupling interactions and magnetic anisotropy in a family of experimentally synthesized and theoretically modeled M′₆M₈(CN₂₄) (M′=Cu^II, Ni^II or Co^II; M=Fe^III or Cr^III) systems is presented. The calculations show that the interactions in the selected M′₆M₈(CN₂₄) are all ferromagnetic and the near cubic symmetry of Cu₆Fe₈ is the origin of its negative magnetic anisotropy parameter D.     

Über die Ordnung von BIII und MV in Perowskiten vom Typ ABIIIMVO6 (AII  Ba,Sr; MV  Sb,Nb, Ta)

On the Ordering of B^III and M^V in Perovskites of Type A B^IIIM^VO₆ (A^II ? Ba, Sr; M^V ? Sb, Nb, Ta) The perovskites Ba₂B^IIISbO₆ crystallize monoclinic (B^III ? La, Pr, Nd) and cubic (B^III ? Sm, Eu, Gd, Tb, Dy, Yb, Lu, Y) respectively. The Sr compounds, Sr₂B^IIISbO₆, have a monoclinic (B^III ? Nd, Sm, Eu, Dy), orthorhombic (B^III ? Yb, Lu, Y, Sc) or cubic (B^III ? In, Ga) perovskite structure. By intensity calculations and vibrational spectroscopic investigations deviations from a complete order between B^III and Sb^V are detectable. For perovskites Ba₂B^IIIM^VO₆ with M^V ? Nb, Ta the incompleteness of cationic order can be demonstrated as well.     

Beiträge zur Komplexchemie der Phosphine und Phosphinoxide. XXIII. Schwermetallkomplexe des Tetramethyl-biphosphins

On the coordination chemistry of phosphines and phosphinoxides. XXIII. Heavy metal complexes of tetramethyl-biphosphine The reactions of tetramethyl-biphosphine with salts of 3d elements including Cd and Hg, too, in THF, benzene, acetonitrile and alcohols, respectively, results in forming complexes of differing compositions: (MⁿX_n)₂{(CH₃)₂P? P(CH₃}₂)₃? Mⁿ = Ti^III, V^III, Cr^III, Fe^II, Ni^II, Cu^I; MX₂{(CH₃)₂P? P(CH₃)₂}₂? M = Co^II, Ni^II, Hg^II; MX₂ · (CH₃)₂P? P(CH₃)₂? M = Fe^II, Ni^II, Zn, Cd, Hg^II; X = Cl, Br, J. The partly intensively coloured complexes have low solubilities; this item complicates the performing of structure determining methods. Partial informations about the structures of the complexes are to be gained by magnetic and spectrophotometric measurements and X-ray investigations. The tendency of (CH₃)₂P? P(CH₃)₂ to form complexes with transition metals differs from that of other biphosphines. Splitting of the P? P bond due to metal salts does not occur. (CH₃)₂P? P(CH₃)₂ acts as a monodentate or bidentate ligand, like other members of the R₂P? PR₂ series do too. The forming of ligand bridges seems to be favoured in comparison to the chelate function.     

Neue Fluoride MIIIMIVF7 mit MIII = SE,Tl und MIV = Sn,Pb, Pt

New Fluorides M^IIIM^IVF₇ with M^III = SE, Tl and M^IV = Sn, Pb, Pt Colourless Fluorides MSnF₇ (M = La, Sm, Gd, Yb, Lu, Tl), TlPbF₇ and yellow compounds MPtF₇ (M = Eu, Y, Lu) were obtained for the first time either as single crystals or powder samples. They crystallize isostructural to SmZrF₇ (space group P2₁/c-C_2h⁵, Nr. 14; P2₁/n, Z = 4). Crystal data see “Inhaltsübersicht”.     

Über röntgenographische Einkristalluntersuchungen an Na2FeAlF7, Na2MIIGaF7 (MII = Ni,Zn) und Na2ZnFeF7 und die Strukturchemie der Weberite

On X-Ray Single Crystal Studies of Na₂FeAlF₇, Na₂M^IIGaF₇ (M^II = Ni, Zn), and Na₂ZnFeF₇ and the Structural Chemistry of Weberites At single crystals of the orthorhombic weberite Na₂NiGaF₇ (a = 716.1, b = 1021.6, c = 740.9 pm; Imma, Z = 4) and of the monoclinic variants (C2/c, Z = 16) Na₂FeAlF₇ (a = 1242.6, b = 727.8, c = 2420.6 pm, β = 99.99°), Na₂ZnGaF₇ (a = 1251.9, b = 730.3, c = 2435.3 pm, β = 99.74°) and Na₂ZnFeF₇ (a = 1261.0, b = 7.359, c = 2453.8 pm, β = 99.70°) complete X-ray structure determinations were performed. The results and the influence of radii on the bridge angles M^II–F–M^II and M^II–F–M^III are discussed in connection with general features within the structural chemistry of 28 weberites.     

Crystal Structure of a New Acentric Oxide Fluoride of VIV: BaVOF4

The structure of BaVOF₄ has been determined by X-ray diffraction data from a single crystal obtained by hydrothermal synthesis: S.G. Fdd2 (acentric), Z = 16, a = 7.920(1), b = 27.608(2) and c = 7.375(1) Å with R = 0.0262 and R_w = 0.0273 for 1 508 independent reflections and 64 parameters. The network is built up from cis-linked VOF₅ octahedra forming infinite kinked chains running along the [101] and [101] directions, connected by barium cations. The location of O^2? and F^? ions is discussed using bond valence calculations. As for BaTiOF₄ and some compounds in the series A^IIM^IIIF₅ (A = Ba, Sr and M = Ga, Al, Mn), the structure can be described in terms of a quasi hexagonal compact planes stacking of Ba²⁺, O^2? and F^? ions.     

Kristallstrukturbestimmungen an vier monoklinen Weberiten Na2MIIMIIIF7 (MII = Fe,Co; MIII = V,Cr)

Crystal Structure Determinations of Four Monoclinic Weberites Na₂M^IIM^IIIF₇ (M^II = Fe, Co; M^III = V, Cr) By solid state reaction of the binary fluorides single crystals of the following weberites were prepared and their monoclinic structure (space group C2/c, Z = 16) determined by X-ray methods: Na₂FeVF₇ (a = 1 271.0(3), b = 742.9(1), c = 2 471.6(5) pm, β = 100.03(3)°; R₁ = 0.043 (1 545 Reflexe); Fe? F = 203.8, V? F = 193.0 pm); Na₂FeCrF₇ (a = 1 262.5(3), b = 739.1(1), c = 2 460.5(5) pm, β = 99.93(3)°; R₁ = 0.029 (2 340); Fe? F = 203.6, Cr? F = 190.5 pm); Na₂CoVF₇ (a = 1 270.3(5), b = 739.1(3), c = 2 465.1(10) pm, β = 100.02(3)°; R₁ = 0.028 (2 250); Co? F = 201.6, V? F = 193.6 pm); Na₂CoCrF₇ (a = 1 257.8(3), b = 733.5(1), c = 2 441.5(5) pm, β = 99.64(3)°; R₁ = 0.030 (2 227); Co? F = 201.2, Cr? F = 190.2 pm). Concerning the above average distances within the distorted [MF₆] octahedra and the shape of [NaF₈] coordination details are given and discussed.     

Untersuchungen an quaternären Fluoriden LiMIIMIIIF6, Über die Kationenverteilung in Fluortrirutilen

Inhaltsübersicht. Fluortrirutile LiM^IIM^IIIF₆ kristallisieren tetragonal in dor Raumgruppe P4₂/mnm mit Li in Position (2a) und M^II und M^III statistisch vorteilt in (4e). An Einkristallen und durch Pulvermessungen wurde die Verteilung der Kationen untersucht, wozu die neu dargestellte Rhodiumverbindung LiZnRhF₆ auf Grund des unterschiedlichen Streuvermögens der Kationen besonders geeignet war. Verbindungen LiCuM^IIIF₆ zeigen die einfache Rutilstruktur. Investigations of the Quaternary Fluorides LiM^IIM^IIIF₆. On the Distribution of Cations in Fluorotrirutiles Abstract. Trirutiles LiM^IIM^IIIF₆ crystallize tetragonally in the space group P4₂/mnm with Li in position (2a) und M^II and M^III statistically distributed in (4e). By single-crystal X-Ray diffraction and by powder work cation ordering was examined for which the new compound LiZnRhF, was especially adapted. Compounds LiCuM^IIIF₆ are disordered rutile phases.     

Struktur‐ und magnetochemische Untersuchungen an den ternären Phosphaten Ba2MII(PO4)2 (MII = Mn,Co) und Strukturverfeinerung von BaNi2(PO4)2

Structural and Magnetochemical Studies at the Ternary Phosphates Ba₂M^II(PO₄)₂ (M^II = Mn, Co) and Refinement of the Crystal Structure of BaNi₂(PO₄)₂ Single crystals of the following phosphates were grown by the floating zone technique using a mirror furnace and their crystal structures refined (0,02 < R₁ < 0,04 and 0,04 < wR₂ < 0,10, resp.): Ba₂Mn(PO₄)₂ (a = 531.1(1), b = 896.8(1), c = 1625.6(3) pm, β = 90.26(1)°), Ba₂Co(PO₄)₂ (a = 529.8(1), b = 884.4(1), c = 1614.4(3) pm, β = 90.68(2)°) and BaNi₂(PO₄)₂ (a = 480.0(1), c = 2327.3(5) pm, Z = 3, space group R3). Both compounds Ba₂M^II(PO₄)₂ crystallize with Z = 4 in space group P2₁/n of the monoclinic Ba₂Ni(PO₄)₂ type; BaNi₂(PO₄)₂ has the hexagonal‐rhombohedral structure of the BaNi₂(AsO₄)₂ type. Magnetic measurements of powders of Ba₂Mn(PO₄)₂ and Ba₂Co(PO₄)₂ yielded room temperature moments of μ_eff = 5,73 and 4,93 μ_B, resp., but only the manganese compound obeys the Curie‐Weiss law down to low temperatures. Weak antiferromagnetic interactions at both compounds only near T_M ≈ 5 K lead to a reciprocal susceptibility minimum.     

Zur Kenntnis des Systems Cs/Cu/F: Über CsCuIICuIIIF6

The System Cs/Cu/F: On CsCu^IICu^IIIF₆ ?CsCuF_3,6’? is described in literature as a darkbrown powder which is supposed to crystallize in a cubic lattice (a = 882 pm, Debyeogramms). However Guinier photographs show that ?CsCuF_3,6’? is a mixture of CsCu^IICu^IIIF₆ (black, isotypic to CsNi^IINi^IIIF₆, a = 706.7 b = 727.7, c = 1032.2 pm, Z = 4) and Cs₂CuCu^IIIF₆ (auburn, pseudocubic, a = 623.4 c = 886.4 pm, Z = 2).     

Beiträge zur Komplexchemie der Phosphine und Phosphinoxide. XXXI. Cobalt- sowie Rhodiumkomplexe primärer Mercaptoalkylphosphine und Bemerkungen zur Komplexbildung quadridentater P,P,S,S-Liganden

On the Coordination Chemistry of Phosphines and Phosphinoxides. XXXI. Cobalt and Rhodium Complexes of Primary Mercaptoalkylphosphines and Remarks on the Complex Formation of Quadridentate P,P,S,S Ligands Primary Mercaptoalkylphosphines (H₂P? CH₂ · CH₂? SH; H₂P? CH₂ · CHCH₃? SH) react with d⁷-metal salts to give octahedron 1:3 chelat complexes. In case of cobalt the oxidation of Co^II to Co^III are obtained by formation of H₂. Structure and properties of these complexes as well as their reactivity like S-alkylation or metallation with following reactions are described. Reaction scheme see ?Inhaltsübersicht”?. With quadridentate ligands HS+ +PH+ +PH+ +SH = L result chelat-complexes of the type [M^III? L XNH₃] (M = Co, Rh) and such as [M^II? L] (M = Ni, Pd, Pt).     

Über Verbindungen vom Typ Ba3BIIMO9 mit BII  Mg,Ca, Sr,Ba und MV  Nb,Ta

Compounds of the Type Ba₃B^IIM O₉ with B^II ? Mg, Ca, Sr, Ba, and M^V ? Nb, Ta The hexagonal perovskites Ba₃B^IIMO₉ (M^V ? Nb, Ta) crystallize with B^II ? Mg Ca in a 3 L structure (sequence (c)₃) and B^II ?; Sr in the hexagonal BaTiO₃ type (6 L; sequence (hcc)₂) with an 1:2 order for the B and M ions. Intensity calculations for Ba₃SrNb₂O₉ and Ba₃SrTa₂O₉ gave in the space group P6₃/mmc a refined, intensity related R′ value of 8.4% (Nb) and 9.0% (Ta) respectively. For B^II ? Ba the perovskite Ba₃BaTa₂O₉ has an orthorhombic distorted 6 L structure and forms with Ba₃SrTa₂O₉ a continuous series of mixed crystals (Ba₃Sr_1?xBa_xTa₂O₉). In the system Ba₃Sr_1?xBa_xNb₂O₉ the range of existence of the hexagonal BaTiO₃ type is confined to the Sr richer end. The pure Ba compound possesses a proper structure type (5 L: Ba₅BaNb₃□O_13.5□_1.5).     

Ternäre Fluoride mit vierwertigem Chrom: M″CrF6mit M″ = Ba,Sr, Ca,Mg, Zn,Cd, Hg,Ni

Ternary fluorides with tetravalent chromium: M^IICrF₆ with M^II = Ba, Sr, Ca, Mg, Zn, Cd, Hg, Ni. We obtained hithertoo unknown BaCrF₆ (light yellow) and SrCrF₆ (yellow), both of (hexag.) BaSiF_B-type [a = 7.32₈, c = 7.13₇ Å; and a = 7.10₉ c = 6.86₃ Å, respectively] as well as CaCrF₆ (pink) [a = 5.33₆, c = 14.15₃ Å], MgCrF₆ (pink) [a = 5.09₁ c = 13.14₃ Å], CdCrF₆ (pink) [a = 5.14₆, c = 14.07₅ Å] and HgCrF₆ (orange-yellow) [a = 5.12₈, c = 14.26₅ A], all of (hexag.) LiSbF₆-type. NiCrF₆ (brown) [a = 4.97₅, c = 13.26₂ Å] and ZnCrF₆ (orange-yellow) [a = 5.02₆, c = 13.33₇ Å] crystallize in the hexag. VF₃-type.