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.     

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.     

Copper Weberites: Crystal Structure and Magnetic Investigation of Na2CuGaF7 and Na2CuInF7

The crystal structures of two new copper weberites Na₂CuGaF₇ and Na₂CuInF₇ have been determined. Na₂CuGaF₇ has the monoclinic space group C2/c: a = 1232.5(5) pm, b = 731.8(1) pm, c = 1278.0(5) pm, β = 109.29(2)° and Z = 8. Na₂CuInF₇ crystallizes in the orthorhombic space group Pmnb: a = 731.8(1) pm, b = 1060.2(2) pm, c = 771.2(1) pm and Z = 4. The structures have been refined from 1175 reflections to R = 0.043 (wR = 0.035) for Na₂CuGaF₇, and from 1917 reflections to R = 0.034 (wR = 0.025) for Na₂CuInF₇. The structures consist of [CuF₅]_n^3n? chains which are parallel the a-axis in Na₂CuInF₇ and oriented in two alternating directions in Na₂CuGaF₇. Sodium atoms exhibit either seven-fold or eight-fold coordination. Although strong antiferromagnetic interactions are observed inside the chains, there is no evidence for three-dimensional ordering.     

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.     

The 1-6 weberite Na2Te2O7 and some observations on compounds with the weberite structure

The 1-6 weberite Na₂Te₂O₇ (Imm2, a = 7.233 Å, b = 10.104 Å, c = 7.454 Å) has been prepared by high-pressure synthesis. It is shown that $\text{a}$) (the mean unit-cell dimension per formula unit) of oxide weberites A₂B₂O₇ can be represented as a linear function of the effective ionic radii of A and B. The problem of the true space-group symmetry of weberite is discussed.     

Die Kristallstrukturen der Weberite Na2CuScF7 und Na2ZnAlF7

The Crystal Structures of the Weberites Na₂CuScF₇ and Na₂ZnAlF₇ At single crystals of the orthorhombic weberites Na₂CuScF₇ (Pmnb, Z = 4) and Na₂ZnAlF₇ (Imma, Z = 4) X-ray structure determinations were performed. Na₂CuScF₇ (Na₂ZnAlF₇): a = 726.0 (709.2), b = 1053.4 (1009.2), c = 765.8 (733.7) pm; R1 = 0.030 (0.042) for 887 (363) observed and independent reflections. The resulting average distances of the octahedrally coordinated metal atoms are: Cu? F = 200.7 pm, Sc? F = 201.7 pm; Zn? F = 198.8 pm, Al? F = 180.1 pm. Some structural relations and the variation in the bridge angles of the corner-sharing octahedra are discussed.     

Na7I2(OH)5: Ein Hydroxidiodid im System NaOH/NaI

Na₇I₂(OH)₅: A Hydroxide Iodide in the System NaOH/NaI The pseudobinary system NaOH/NaI is investigated by X-ray methods. The crystal structure of the compound Na₇I₂(OH)₅ was solved by single crystal data: Na₇I₂(OH)₅: P4/nmm, Z = 2, a = 7.748(2) Å, c = 10.260(3) Å, Z(F_o) = 443 with (F_o)² ≥ 3σ(F_o)², Z(parameter) = 28, R/R_w = 0.044/0.059 Na₇I₂(OH)₅ crystallizes in a new type of structure which contains puckered layers of ∞²[Na₇(OH)₅²⁺] connected via iodide ions.     

Über Usovite Ba2M″ M″ M2″ F14 und die Hochdruckphasen von BaMnVF7 und BaMnFeF7: Verbindungen mit BaMnGaF7-Struktur

On Usovites Ba₂M^IIM′^IIM₂^IIIF₁₄ and the High Pressure Phases of BaMnVF₇ and BaMnFeF₇: Compounds with BaMnGaF₇ Structure The results of complete single crystal structure determinations of the monoclinic BaMnGaF₇ type compounds Ba₂CaCoV₂F₁₄ (and Ba₂CdMn Fe₂F₁₄) are reported: C2/c, Z = 4, a = 1369.7 (1381.2), b = 538.4 (537.2), c = 1491.6 (1489.5) pm, β = 91.49 (91.11)°, Rg = 0.036 (0.038) for 4389 (2521) reflections. The atoms Ca/Co (Cd/Mn) distribute not completely ordered on the 8? and 6?coordinated sites of this “usovite” structure (Ba₂CaMgAl₂F₁₄). This is also evident for Cd/Fe from Mössbauer spectra of Ba₂CdFeAl₂F₁₄. The lattice constants of this and further seven compounds Ba₂M^IIM′^IIM2_IIIF₁₄ (M^II = Ca, Cd; M′^II = Mg, Mn? Cu; M^II = Al, Ga) are given. Two novel representatives of the same structure with M^II = M′^II = Mn could be prepared in the form of the high pressure phases of BaMn VF₇ and BaMnFeF₇. The magnetic properties of both modifications of the iron compound and of BaMnGaF₇ are reported and discussed.     

Die Kristallstruktur von Na2NiAlF7—ein Beitrag zum Problem der wahren Raumgruppe orthorhombischer Weberite

The Crystal Structure of Na₂NiAlF₇ — a Contribution to the Problem of the True Space Group of Orthorhombic Weberites The X-ray single crystal structure determination of the orthorhombic weberite Na₂NiAlF₇ (a = 707.4(2), b = 1003.8(2), c = 731.5(1) pm; Z = 4) was performed in space group Imma, after all reflections hk0 with h(k) = 2n + 1 could be eliminated, as they proved simulated by Renninger effect and/or λ/2 reflections. The alternative space groups Imm2 resp. I2₁2₁2₁ of former weberite structure determinations thus became obsolete. The refinement using 880 independent reflections ended at wR = 0.0232. The resulting average distances within the framework of octahedra are Ni? F = 197.3, Al? F = 180.4 pm.     

Neue Fluorozirconate und ‐hafnate mit V2+ und Ti2+

New Fluorozirconates and ‐hafnates with V²⁺ and Ti²⁺ During investigations of the systems MF₂/KF/MF₄ e. g. MF₂/NaF/MF₄ (M²⁺ = Ti²⁺, V²⁺, M⁴⁺ = Zr⁴⁺, Hf⁴⁺) we obtained blue crystals of VZrF₆, VHfF₆, KVZrF₇, blue‐green crystals of NaVHf₂F₁₁, yellow crystals of TiHfF₆ and NaTiHf₂F₁₁, and yellow to rubyred crystals of TiZrF₆, respectively. According to single crystal data, VZrF₆ VHfF₆ and TiZrF₆ crystalizes in the ordered ReO₃‐type (cubic, Fm3m, a = 812,1(5), 804,2(8), and 821,0(2) pm, Z = 4). TiHfF₆ crystalizes in a high‐temperature‐modification (cubic, ReO₃‐type, Pm3m, a = 392,3(2) pm, Z = 2). KVZrF₇ is isotyic to KPdZrF₇ (orthorhombic, Pnna, a = 1109,8(6), b = 788,0(7), c = 648,0(15) pm, Z = 4). NaTiHf₂F₁₁ and NaVHf₂F₁₁ crystalizes monoclinic (C2/m, a = 910,5(7), b = 675,9(7), c = 773,6(5) pm, β = 116,10(6)° and a = 917,7(5), b = 685,7(5), c = 752,4 pm, β = 118,28(1)°, Z = 2, respectively) and are also isotypic to already known AgPdZr₂F₁₁.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

Na5Br(OH)4: Darstellung und Kristallstruktur einer Verbindung im System NaOH/NaBr

Na₅Br(OH)₄: Synthesis and Structure of a Compound in the System NaOH/NaBr The pseudobinary system NaOH/NaBr is investigated by X-ray methods. The structure of the compound Na₅Br(OH)₄ was solved by single crystal data: Na₅Br(OH)₄: Pnma, Z = 8, a = 11.846(2) Å, b = 18.782(4) Å, c = 6.431(1) Å, Z(F_o) = 1 202 with (F_o)² ≥ 3σ(F_o)², Z(parameter) = 100, R/R_w = 0.030/0.035 The compound crystallizes in a new type of structure. Pairs of octahedra around O by 5 Na and 1 H to [Na₅(OH)]₂ are orientated in such a way to one another that two ions OH^? form a parallelogram hinting to unusual bent hydrogen bridge bonding.     

Crystal structures of CrH2P3O10 and InH2P3O10

The crystal structures of chromium and indium dihydrogen triphosphates, CrH₂P₃O₁₀ and InH₂P₃O₁₀, in modification II are refined by the Rietveld method using X-ray powder diffraction data. The compounds crystallize in the monoclinic crystal system, space group P21/n. Z = 4, a = 7.3225(4)Å, b = 8.6835(6)Å, c = 11.6599(7) Å, and b = 102.388(3)° for CrH₂P₃O₁₀, and a = 7.5332(1)Å, b = 9.0841(1)Å, c = 11.8600(1) Å, and b = 103.9596(7)° for InH₂P₃O₁₀. The structures are refined in the isotropic approximation (pseudo-Voigt profile function): R_p = 4.8%, R_wp = 6.9%, R_Bragg = 7.5%, R_F = 9.9% for CrH₂P₃O₁₀; R_p = 6.3%, R_wp = 8.3%, R_Bragg = 6.2%, R_F = 4.1% for InH₂P₃O₁₀. The crystal structures of compounds in the isostructural series M^IIIH₂P₃O₁₀-II, where M^III = Al, Ga, Cr, V, Fe, and In, are examined and compared.     

Zur Kenntnis von Na4Br(NH2)3: Ein Amidbromid im System NaNH2/NaBr

Na₄Br(NH₂)₃: An Amide Bromide in the System NaNH₂/NaBr The pseudobinary system NaNH₂/NaBr was investigated by X-ray methods. The crystal structure of Na₄Br(NH₂)₃ was solved by single crystal data: Pnnm, Z = 4, a = 6.579(2) Å, b = 12.755(4) Å, c = 8.776(2) Å Z(F_o) with (F_o)² ≥ 3σ = (F_o)² = 503, Z(parameter) = 39, R/R_w = 0.082/0.106. It is a new type of structure, built up by a three-dimensional network of [Na₄(NH₂)₃⁺] containing the bromide ions.     

Über Na2PrO3 und Na2TbO3

On Na₂PrO₃ and Na₂TbO₃ Using an exchange reaction of Na₂O with Li₈TbO₆ (Na : Tb = 2.1 : 1; au-tube; 750°C, 30 d) yellow-orange colored single crystals of Na₂TbO₃ could be prepared for the first time. Na₂TbO₃ crystallizes monoclinic in C2/c (Z = 8; a = 576.92(6), b = 1001.27(9), c = 1117.91(14) pm, β = 99.98(1)°). According to four-circle data the Li₂SnO₃-type of structure is adopted (PW 1100, MoKα , 1935 I₀ (hkl), R = 4.86%, R_w = 3.63% for all 928 unique reflexions). By a similar exchange reaction of Na₂O with Li₈PrO₆ for the first time single crystals of Na₂PrO₃ could be prepared, too (Na : Pr = 2.2 : 1; au-tube; 700°C; 23 d). The structure determination reveils that there is a variant of the NaCl-type of structure, which ressembles to the Li₂SnO₃-type of structure (PW 1100, MoKα , 2199 I₀ (hkl)), R = 8.88%, R_w = 5.21% for all 947 unique reflexions; C2/c, Z = 8, a = 678.78(5), b = 977.47(7), c = 1080.38(9) pm, β = 108,4(1)°. In contrast to Na₂TbO₃ there are no layers according to NaO(Na_1/3Tb_2/3)O. All octahedral intersticies are occupied systematically with Pr⁴⁺ and Na⁺ : (Na_2/3Pr_1/3)O(Na_2/3Pr_1/3)O.     

Na2Mn(NH2)4: Ein neuer Schichtenstrukturtyp

Na₂Mn(NH₂)₄: A New Type of Layered Structure The structure of Na₂Mn(NH₂)₄ was solved by X-ray single crystal data including H-positions: P2₁/c, Z = 4, a = 6.331(1) Å, b = 14.542(3) Å, c = 7.212(1) Å, β = 116.29(1)°, Z(F ≥ 3σ = (F)) = 1343, Z(parameters) = 96, R/R_W = 0.023/0.029. The compound crystallizes in a new type of structure. Within layered blocks the amide ions are arranged with the motif of a hexagonal closest packing of spheres. Within these blocks alternating layers contain sodium in all octahedral sites and manganese in an ordered way in a quarter of tetrahedral sites.     

Na2ZrS3: Ein ternäres Sulfid des Zirconiums mit aufgefüllter AlCl3‐Struktur

Na₂ZrS₃: A Ternary Zirconium Sulfide with Stuffed AlCl₃‐type Structure Dark green, plate‐like single crystals of Na₂ZrS₃ (monoclinic, C2/m; a = 664.69(6), b = 1152.5(1), c = 695.48(7) pm, β = 108.78(1)°; Z = 4) are obtained along with pale yellow platelets of NaZr₂N₂SCl (trigonal, R3m; a = 363.56(3), c = 2951.2(4) pm; Z = 3) upon oxidation of zirconium metal with sulfur and sodium azide (NaN₃) in the presence of fluxing NaCl (molar ratio 7:6:2:3) in evacuated silica tubes at 850°C within three weeks. The crystal structure is best described as stuffed AlCl₃ type with all cations (Na⁺ and Zr⁴⁺) in octahedral coordination of the S^2– anions, which build up a cubic closest packed host lattice. The internuclear metal sulfur distances range from 276 to 296 pm for all three crystallographically different Na⁺ cations, and from 258 to 260 pm for Zr⁴⁺.     

Na7Y2(P2O7)2 (P3O10) – A New Layer and Tunnel Structure

A new layered phosphate, Na₇Y₂(P₂O₇) ₂(P₃O₁₀), containing both [P₂O₇]^4? and [P₃O₁₀]^5? groups, has been prepared. It crystallizes in the monoclinic space group P2/c with a = 16.205(4), b = 5.3746(9), c = 12.309(4) Å, β = 97.96(2)°, V = 1061.7(5) ų and Z = 2. The structure was solved and refined to R₁ = 0.0298 and wR₂ = 0.0698 for 1844 independent reflections with I > 2σ(I). It consists of layers of corner and edge-sharing YO₇ polyhedra, P₂O₇ and P₃O₁₀ groups. Each layer is built up from two parallel [YP₂O₇] slabs, held together by the P₃O₁₀ groups. This arrangement gives rise to intersecting tunnels within the layer. The Na⁺ cations are located in the tunnels and between the layers. Both P₂O₇ and P₃O₁₀ groups contain unshared oxygen atoms directed toward the interlayer space and toward the tunnels. The P₂O₇ groups show a staggered configuration. In addition to this original layered framework, the title compound provides the third example of a compound containing a mixed anion of [P₂O₇]^4? and [P₃O₁₀]^5?. The structure was compared with the two previously reported ones, containing such a mixed anion: NH₄Cd₆(P₂O₇) ₂(P₃O₁₀) [6] and Cs₂Mo₅O₂(P₂O₇)₃ · (P₃O₁₀) [7].     

Neue Heteropolyanionen des M2X2W20‐Typs mit Antimon(III) als Heteroatom

New Heteropolyanions of the M₂X₂W₂₀ Structure Type with Antimony(III) as a Heteroatom The syntheses of two new heteropolyanions of the M₂X₂W₂₀ structure type are presented. They are characterized by X‐ray structure analysis and vibrational spectra. Na₆(NH₄)₄[Zn₂(H₂O)₆(WO₂)₂(SbW₉O₃₃)₂]·36H₂O (1) is monoclinic (P2₁/n) with a = 12.873(3)Å, b = 25.303(4)Å, c = 15.975(4)Å and β = 91.99(3)°. Na₁₀[Mn₂(H₂O)₆(WO₂)₂(SbW₉O₃₃)₂]·40H₂O (2) also crystallizes in the space group P2₁/n with a = 12.892(3)Å, b = 25.219(5)Å, c = 16.166(3)Å and β = 94.41(3)°. Both polyanions are isostructural to anions of this structure type containing other heteroatoms. They are built up by two β‐B‐SbW₉ fragments, which are derived from defect structures of the Keggin anion. These subÍunits are connected by two formal WO₂ groups with further stabilization by addition of two M(H₂O)₃ groups (M = Zn^II, Mn^II, Fe^III, Co^II) leading to the M₂X₂W₂₀‐type heteropolytungstates.