Über Cs2Li2[GeO4]

About Cs₂Li₂[GeO₄] By heating of a well-ground mixture of the binary oxides CsO_0.55, Li₂O and GeO₂ (Cs:Li:Ge=2,6:2,2:1; Ni-tube; 600 °C; 49d) we got single crystals of Cs₂Li₂[GeO₄] for the first time. Cs₂Li₂[GeO₄] is isotypic to Rb₂Li₂[MO₄] [M = Si, Ti, Ge] [2] and Cs₂Li₂[MO₄] (M = Si, Ti) [3]: according to this Cs₂Li₂[GeO₄] crystallizes triclinic, in the spacegroup P1 with a = 968.7(4) pm, b = 586.0(2) pm, c = 571.4(2) pm, α = 92.71(4)°, β = 110.95(3)° and γ = 94.34(4)° (Guinier-Simon data), Z = 2. The structure was determined by four-circle diffractometer data (Ag? K_α ; 2381 I_o(hkl); R = 8,4%; R_w = 5.0%), parameters see text. Further the Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN) and the Mean Fictive Ionic Radii (MEFIR), have been calculated.     

Über quaternäre Oxoplumbate(IV). Zur Kenntnis von Rb2Li14[Pb3O14] und Cs2Li14[Pb3O14]

On Quaternary Oxoplumbates(IV). On the Knowledge of Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] For the first time, Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] have been prepared by heating of mixtures of Li₂O, β-?PbO₂”? and Rb₂PbO₃, Cs₂PbO₃ respectively with Li:Pb:A = 14:3:2, (A = Rb, Cs). [Ag-cylinders, sealed under vacuum in Duran-glass ampoule, 590 and 550°C, 40 d, powder (650°C, 200 d, single crystals of Rb₂Li₁₄[Pb₃O₁₄])]. Rb₂Li₁₄[Pb₃O₁₄] is nearly colourless with ivory nuance, Cs₂Li₁₄[Pb₃O₁₄] is pale yellow. According to powder and single crystal investigations, both are isotypic with K₂Li₁₄[Pb₃O₁₄]. Structure refinement of Rb₂Li₁₄[Pb₃O₁₄]: 1015 symmetry independent reflexions, four-circle-diffraktometer PW 1100 (Fa. Philips), ω-scan, MoKα, R = 5.73%, R_W = 5.33%, absorption not considered, space group Immm with a = 1284.71(9), b = 793.90(4), c = 727,35(5) pm, d_x-ray = 4.99 g · cm^?3, d_pyc = 5.01 g · cm^?3, Z = 2. Cs₂Li₁₄[Pb₃O₁₄]: a = 1295.28(12), b = 796.69(8), c = 732.44(7) pm, d_x-ray = 5.31 g · cm^?3, d_pyc = 5.28 g · cm^?3, Z = 2. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.     

Neue Oxoferrate(III). Na2Li3[FeO4] und K2Li3[FeO4]

New Oxoferrates (III). Na₂Li₃[FeO₄] and K₂Li₃[FeO₄] . Na₂Li₃[FeO₄] and K₂Li₃[FeO₄] (transparent, pink or light yellow single crystals) have been prepared by heating mixtures of the oxides (Na:Li:Fe = 2.2:3.3:1; Ag-tube, 720°C, 27 d or K:Li:Fe = 2.2:3.3:1; analogous, 700°C, 40 d). Na₂Li₃[FeO₄] is isotypic with Na₂Li₃[GaO₄] (a = 832.2(1), b = 796.0(1), c = 656.3(1)pm, Pnnm) and K₂Li₃[FeO₄] with K₂Li₃[GaO₄] (a = 557.7(1), b = 880.6(1), c = 1101.8(2)pm, β = 111.51(2)°, P2₁/c). Four cycle diffractometer data: MoK_α, 525 out of 686 I₀(hkl), R = 9.36%, R_w = 5.97% or 1424 out of 1424 I₀(hkl), R = 8.45%, R_w = 5.66%. Parameters see text. The structures are characterized by calculations of the Madelung Part of Lattice Energy, MAPLE. The Effective Coordination Numbers, ECoN, which are calculated by means of Mean Fictive Ionic Radii, MEFIR, are compared with the analogous gallates.     

Neue Vertreter des K2Li14[Pb3O14]-Typs Cs2Li14[Tb3O14] und K2Li14[Zr3O14] [1, 2]

Inhaltsübersicht. Erstmals wurden klar durchscheinende, orange-farbene Einkristalle von Cs₂Li₁₄[Tb₃O₁₄] aus Cs₂TbO₃ und Li₂O (Tb: Li = 1:5) dargestellt [550°C, 21 d, verschlossenes AuRohr]. Es liegt der K₂Li₁₄[Pb₃O₁₄]-Typ vor [Vierkreisdiffraktometerdaten, PW 1100, MoKä-Strahlung, 660 I_o(hkl), R = 4,8%, R_w = 3,4%, Immm, a = 1293,5(8), b = 792,6(3), c = 740,4(3) pm, Z = 2, d_rö = 4,65]. Ebenfalls neu wurde K₂Li₁₄[Zr₃O₁₄] in Form farbloser Einkristalle durch Tempern inniger Gemenge von K₂O, Li₂O und ZrO₂ (K: Li: Zr = 1:4:1,5) dargestellt [900°C, 14 d, geschlossene Ni-Bombe] und röntgenographisch untersucht. Die Strukturverfeinerung [612 I_o(hkl), Vierkreisdiffraktometerdaten, PW 1100, MoKα-Strahlung, R = 5,9%, R_w = 5,3%, Immm, a = 1244,6, b = 776,4, c = 724,3 pm, Z = 2] bestätigt die Isotypie mit K₂Li₁₄[Pb₃O₁₄]. Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, wurden berechnet. Für die nun bekannten Vertreter dieses Typs wurde ein Isotypievergleich vorgenommen. New Compounds of the K₂Li₁₄[Pb₃O₁₄] Type: Cs₂Li₁₄[Tb₈O₁₄] and K₂Li₁₄[Zr₃O₁₄] For the first time Cs₂Li₁₄[Tb₃O₁₄] has been prepared as orange single crystals from Cs₂TbO₃ and Li₂O (Tb: Li = 1:5) [550°C, 21 d, sealed Au-Tube]. Structure Refinement [four-circle diffractometer data, PW 1100, MoKα radiation, 660 I_o(hkl), R = 4.8%, R_w = 3.4%, Immm, a = 1293.5(8), b = 792.6(3), c = 740.4(3) pm, Z = 2, d_rö = 4.65] confirms isotypy with K₂Li₁₄[Pb₃O₁₄]. K₂Li₁₄[Zr₃O₁₄] has also been prepared as colorless single crystals from K₂O, Li₂O, and ZrO₂ (K: Li: Zr = 1:4:1.5), [900°C, 14 d, closed Ni-cylinder] and investigated by x-ray [612 I_o(hkl), four-circle diffractometer data, PW 1100, MoKα radiation, R = 5.9%, R_w = 5.3%, Immm, a = 1244.6, b = 776.4, c = 724.3 pm, Z = 2]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, are calculated. A detailed comparison of the structures is carried out.     

Darstellung und Kristallstruktur von K6[Al2O6] und Rb6[Al2O6]

Preparation of Crystal Structure of K₆[Al₂O₆] and Rb₆[Al₂O₆] Colourless single crystals of K₆[Al₂O₆] have been prepared from intimate mixtures of KAlO₂ and K₂O (550°C, 90 d). The structure determination from four-circle diffractometer data (MoKα , 742 I_o(hkl), R = 2.2%, R_w = 2.1%) confirms the space group C2/m with Z = 2; a = 698.25 pm, b = 1 103.54 pm, c = 646.49 pm, β = 102.49°. Colourless single crystals of hitherto unknown Rb₆[Al₂O₆] have been prepared from intimate mixtures of RbAlO₂ and Rb₂O (520°C, 120 d). The structure determination from four-circle diffractometer data (MoKα , 1 240 I_o(hkl)) results in the residual values R = 7.2%, R_w = 4.9%; space group C2/m; a = 725.92 pm, b = 1 143.33 pm, c = 678.06 pm, β = 104.05°; Z = 2. K₆[Al₂O₆] and Rb₆[Al₂O₆] are isostructural with K₆[Fe₂O₆]. A characteristic structure unit is the anion [Al₂O₆]^6? consisting of two edge-sharing [AlO₄] tetrahedra. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), the Madelung Part of Lattice Energy (MAPLE) and the Charge Distribution (CHARDI) are calculated and discussed.     

Neue Oxoterbate(IV) mit Lithium Rb2Li14[Tb3O14] und Li6Tb2O7

New Oxoterbates(IV) with Lithium: On Rb₂Li₁₄[Tb₃O₁₄] and Li₆Tb₂O₇ For the first time we prepared Rb₂Li₁₄[Tb₃O₁₄] as yellow single crystals from Li₈TbO₆ and Rb₂O (Tb:Rb = 1:2) [Ag-cylinder, 500°C, 30 d, then Au-tube, 700°C, 27 d]. The structure refinement [652 I₀ (h kl), four circle diffractometer Philips PW 1100, ω-scan, MoKα, R = 4.69%, R_w = 3.24%, absorption considered, Immm with a = 1 283.07(10), b = 790.87(7), c = 736.87(7)pm, Z = 2, d_x = 4.30 g · cm^?3] confirms that it is isotypic with K₂Li₁₄[Pb₃O₁₄]. Furthermore we got for the first time Li₆Tb₂O₇ as a bright yellow compound from Li₂O₂ and “Tb₄O₇*” [(Li:Tb = 3.4:1), Au-ube, 750°C, 13 d (powder), 850°C 22 d (single crystals)] and by thermal decomposition of Rb₂Li₁₄[Tb₃O₁₄] (Au-tube, 850°C, 25 d). Powder and single crystal data [1 327 I₀ (h kl), four circle diffractometer PW 1100, ω-scan, AgKα, R = 9.38%, R_w = 5.23%, absorption not considered, P2₁/a, a = 1 056.30(10), b = 613.50(4), c = 546.56(5) pm, β = 109.668(7)°, Z = 2, d_x = 4.67 g · cm^?3 d_pyc = 4.53 g · cm^?3] reveal a new type of structure that may be deduced by the NaCl-type of structure. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Ein neues Cobaltat mit Inselstruktur: Li6[CoO4]

A New Cobaltate with Isolated Anion Structure: Li₆[CoO₄] For the first time transparent, blue single crystals of Li₆[CoO₄] have been prepared (Li₂O/Na₂O/?CoO”? (Li:Na:Co = 1.3:1.3:1), Co-tube, 580°C, 22 d). Corresponding to Li₆□CoO; it is an ordered variant of the Li₂O-type of structure: P4₂/nmc; a = 653.6(1) pm, c = 465.4(1) pm; Z = 2; d_x = 2.75 g cm^?3, d_pyk = 2.71 g cm^?3 (4-circle-diffractometer-data (PW 1100), AgKα; 230 from 936 I₀(hkl); R = 9.58%, R_W = 5.25%). Parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed. The magnetic properties are measured in the temperature range of 14–297 K.     

Synthese,Kristallstrukturen und Absorptionsspektren der neuen „Cupriosilicate”︁: K6[CuSi2O8] und Rb4[CuSi2O7]

Synthesis, Crystal Structures, and Absorption Spectra of the New “Cupriosilicates”: K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] were obtained by annealing intimate mixtures of K₂O and Rb₂O, respectively, CuO and SiO₂ in sealed Ag cylinders at 500°C as transparent greenish-blue single crystals. The structure solution (IPDS-data Mo Kα; K₆[CuSi₂O₈]: 1292 F²(hkl), R1 = 0.059; wR2 = 0.103 and Rb₄[CuSi₂O₇]: 763 F²(hkl), R1 = 0.049; wR2 = 0.114) confirms the space group P1 for both compounds. K₆[CuSi₂O₈]: a = 619.4(2); b = 665.5(2); c = 753.0(2) pm; α = 83.66(3); β = 87.71(3); γ = 70.19(3)°; Z = 1. Rb₄[CuSi₂O₇]: a = 631.9(9); b = 707.5(10); c = 715.2(6) pm; α = 114.2(1); β = 100.7(1); γ = 107.9(1)°; Z = 1. The Madelung Part of the Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these calculated via Mean Effective Ionic Radii, MEFIR, are given. The absorption spectra of K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] are discussed in terms of the Angular Overlap Model, AOM.     

Neue Metalloxide mit Tetraeder-Doppel als Baugruppe: Rb6[Tl2O6] und Cs6[In2O6]

New Metal Oxides with Doubles of Tetrahedra as Building Units: Rb₆[Tl₂O₆] and Cs₆[In₂O₆] We prepared the hitherto unknown Rb₆[Tl₂O₆] and Cs₆[In₂O₆] by heating mixtures of Tl₂O₃ and RbO_0.60 (Rb:Tl = 3.5:1) as well as In₂O₃ and CsO_0.53 (Cs:In = 3.5:1) as single crystals [closed Ag-cylinder, 650°C, 14 d]. The single crystals of Rb₆[Tl₂O₆] are yellow, those of Cs₆[In₂O₆] pale yellow, all transparent and rude. The new type of structure was elucidated by 4-circle-diffractometer (PW 1100) data. Rb₆[Tl₂O₆]: P2₁/a; a = 1145,7(3), b = 713,3(1), c = 783,9(2) pm, β = 93,73° (2), Z = 2; Ag–Kα, 2100 out of 2531 I₀(hkl), R = 9,6% and R_w = 8,9%. Cs₆[In₂O₆]: P2₁/a; a = 1178,5(4), b = 730,7(2), c = 816,3(2) pm, β = 95,38° (3), Z = 2; Mo–Kα, 1584 out of 2032 I₀(hkl), R = 9,25%, and R_w = 8,44%. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.     

Neue Alkalioxoarsenate (V) Zur Kenntnis von Rb2Li[AsO4] und Cs2Li[AsO4]

New Alkalioxoarsenates (V). On Rb₂Li[AsO₄] and Cs₂Li[AsO₄] By heating of well-grounded mixtures of the binary oxides (A₂O, Li₂O₂, and As₂O₃; A : Li : As = 2 : 1 : 1; Ni-tube, 550°C, 21 d; A = Rb, Cs) colourless single crystals of Rb₂Li[AsO₄] and Cs₂Li[AsO₄] were obtained for the first time. These new orthoarsenates(V) crystalize orthorhombic (space group C mc2₁? C, No. 36) with Z = 4. As expected they are isotypic with the according orthovanadates(V) [2] A₂Li[VO₄], A = Rb, Cs. The lattice constants of Rb₂Li[AsO₄]: a = 582.1(4) pm, b = 1171.1(7) pm, c = 792.4(5) pm and Cs₂Li[AsO₄]: a = 596.4(2) pm, b = 1223.4(2) pm, c = 819.7(3) pm were taken from Guinier-Simon powder data. The structure was determined by four-circle-diffractometer data [Siemens AED II, MoKα , 6290 I₀ (hkl), R = 3.5%, R_w = 3.2% to Rb₂Li[AsO₄]; 3518 I₀ (hkl), R = 2.8%, R_w = 2.6% to Cs₂Li[AsO₄]; parameters see text]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI are calculated and discussed.     

Über Oxide mit dem “Butterfly-Motiv”: Rb6[Fe2O5] und K6[Fe2O5]

New Oxides with the “Butterfly-Motive”: Rb₆[Fe₂O₅] and K₆[Fe₂O₅] Rb₆[Fe₂O₅] and K₆[Fe₂O₅] were obtained for the first time by annealing intimate mixtures of “Rb₆CdO₄” with CdO (molar ratio 1 : 1.1) and KO_0.48 with CdO (molar ratio 5.9 : 1) respectively in closed Fe-cylinders. Determination and refinement of the crystalstructure confirms the space group C2/m (four-circle-diffractometer data). Rb₆[Fe₂O₅]: Ag Kα , 720 out of 1220 Io(hkl), R = 9.68%, R_w = 6.09%; a = 718.9pm, b = 1183.1 pm, c = 695.4pm, β = 95.05°, Z = 2; K₆[Fe₂O₅]: MoKα , 1214 Out of 12141_o(hkl), R = 3.20070, R_w = 2.48%, a = 691.21 pm, b = 1142.78pm, c = 665.50pm, β = 93.82°, Z = 2. The binuclear unit [O₂FeOFeO₂]^6? already known to be planar with oxoferrates(II) now was observed to be angular here and closely related to Na₆[Be₂O₅].     

Cs4[IrO4], ein neues Iridat mit planarem Anion [IrO4]4−

Cs₄[IrO₄], a New Iridate with Planar Anion [IrO₄]^4? For the first time we obtained black single crystals of Cs₄[IrO₄] by heating intimate mixtures of CsO_0.52 and IrO₂ (molar ratio Cs : Ir = 4.30 : 1.00; “Ag-bomb”, 740°C/86 d). Cs₄[IrO₄] crystallizes monocline, C 2/m, with a = 1031.66(8) pm, b = 671.61(4) pm, c = 660.44(6) pm, b? = 108.118(7)° and Z = 2 in the K₄[IrO₄]-type. The structure has been determined by four-circle-diffractometer data (PW 1100 from Phillips, Ag? Kα , graphite) with 841 I₀(hkl) with I ≥ 3s?(F) (from 947 I₀(hkl) out of 3529 measured reflexes). The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Ein neues Oxozincat: Li6[ZnO4] [1]

A New Oxozincate: Li₆[ZnO₄] Colourless single crystals of Li₆[ZnO₄] are formed by reaction of Li₂O and ZnO [(Li₂O:ZnO = 3.3:1, 700°C 50 d), Space group P4₂/nmc, Z = 2, a = 652.76 pm, c = 465.09 pm R = 2.6%, Rw = 2.1%, 173 symmetry independend I₀(hkl), MoK]. The crystal structure has been determined.     

Li4Sr2[Cr2N6]: Ein Hexanitridodichromat(V)

Li₄Sr₂[Cr₂N₆]: A Hexanitridodichromate(V) The quaternary hexanitridodichromate(V) Li₄Sr₂[Cr₂N₆] was obtained by reaction of the metals with flowing nitrogen at 900 °C as black‐shining crystals with a platy habit. The crystal structure was determined by X‐ray single crystal methods (orthorhombic, Pbca; a = 914.0 pm, b = 735.4 pm, c = 1053.6 pm; Z = 4). The compound contains isolated complex anions [Cr₂N₆]^8— consisting of two tetrahedra CrN₄ sharing a common edge. The distance Cr—Cr in the complex anion is 249.7 pm. The analysis of the Electron Localization Function (ELF) indicates bonding interactions Cr—Cr. Strontium is in a sixfold (distorted octahedral), Lithium in a distorted tetrahedral ([3+1]) coordination by nitrogen. According to measurements of the magnetic susceptibility the compound is diamagnetic.     

Oxydation intermetallischer Phasen: K4{Na2[Tl2O6]} aus NaTl und K2O2

Oxidation of Intermetallic Phases: K₄{Na₂[Tl₂O₆]} from NaTl and K₂O₂ The hitherto unknown K₄{Na₂[Tl₂O₆]} was prepared in form of transparent, yellow single crystals from NaTl and KO_1,08 (molar ratio 1:1.3; sealed Ag-cylinder; 450°C, 30 d). The structure determination (four-circle diffractometer, MoKα, 1 280 out of 1 523 I_o(hkl), R = 5.75%, R_w = 4.58%) confirms the space group P2₁/c with a = 641.3 pm, b = 691.1 pm, c = 1188.5 pm, β = 95.69° and Z = 2. As characteristic building units of the structure there are doubles of tetrahedra of [Tl₂O₆] and [Na₂O₆]. The compound is isotypic with Cs₆[In₂O₆] and Rb₆[Tl₂O₆]. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, CHARDI, are calculated.     

Das erste zweikernige Oxoferrat(II): „Cs2K4[O2FeOFeO2]”︁

The First Binuclear Oxoferrate(II): ?Cs₂K₄[O₂FeOFeO₂]”? For the first time ?Cs₂K₄[Fe₂O₅]”? was obtained by annealing intimate mixtures of Cs₂O, K₂O, and CsFeO₂ (molar ratio Cs : K : CsFeO₂ 1.3 : 2.1 : 1) in a closed Fe-cylinder (74 d; 470°C) in the form of red single crystals. The structure determination (four-circle diffractometer, MoKα , 760 out of 857 I_o(h kl); R = 5.8%, R_w = 4.6%) confirms the space group C2/m; a = 707.4, b = 1138.5, c = 699.7 pm, β = 91.76°, Z = 2. Essential part of the structure is the binuclear, planar [O(1)₂Fe? O(2)? FeO(1)₂]^6? group which is for the first time observed with oxoferrates(II). Despite different space groups the crystal structure is related to that of Rb₂Na₄[Co₂O₅].     

Thio- und Selenomercurate(II). K6[HgS4], K6[HgSe4], Rb6[HgS4] und Rb6[HgSe4]

Thio- and Selenomercurates(II). K₆[HgS₄], K₆[HgSe₄], Rb₆[HgS₄] and Rb₆[HgSe₄] We prepared by annealing intimate mixture of pure samples of K₂S, K₂Se, Rb₂S, and Rb₂Se with HgS or HgSe [360–380°C, 7d, Duran-glass-seal with Argon] with hexagonal Na₆ZnO₄ isotypic new mercurates: K₆[HgS₄] [bright citronic yellow a = 9.98₅, c = 7.65₂ Å], K₆[HgSe₄] [light orange yellow a = 10.3₆, c = 7.88₃ Å], Rb₆[HgS₄] [bright yellow a = 10.3₄, c = 7.94₂ Å], Rb₆[HgSe₄] [orange-red a = 10.7₂, c = 8.19₂ Å]. The crystal structure of K₆ Hgs₄ is elucidated by using diffractometer data of single crystals: P63mc, C⁴_6v, it is R = 6.6% for 304 reflexes [h k o–h k 4, anisotropic refinement MoKα]; for position and parameters see text d_rö = 2.83₅, d_pyk = 2.99 g · cm^?3. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, are calculated and discussed.     

Neue Oxogallate der Alkalimetalle: Über K6[Ga2O6] und Rb6[Ga2O6], sowie Na3GaO3 und Cs6[Ga2O6]

New Oxogallates of Alkaline Metals: On K₆[Ga₂O₆] and Rb₆[Ga₂O₆] as well as Na₃GaO₃ and Cs₆[Ga₂O₆] Due to powder and single crystal data K₆[Ga₂O₆] a = 7.09₉; b = 11.11₆; c = 6.48₄ Å; ß = 101.6₆° and Rb₆[Ga₂O₆] a = 7.39₃; b = 11.47₅; c = 6.79₈ Å; ß = 103.5° crystallize isotypic with K₆[Fe₂O₆]; space group C2/m-C₃^2h; As well has been prepared the hitherto unknown Na₃GaO₃ a = 11.48, b = 10.82, c = 6.13 Å, space-group Imcm or I2cm Z = 8; and Cs₆[Ga₂O₆] a = 7.2₆, b = 12.1, c = 7.6₈ Å, ß = 105°, Z = 4, space-group P2₁/a.     

Ein Oxostannat neuen Strukturtyps: Cs4[SnO4]

An Oxostannate of a New Structure Type: Cs₄[SnO₄] In order to prepare Cs₃LiSnO₄ by heating of a well ground mixture of the binary oxides [CsO_0.67, Li₂O, SnO₂; Cs:Li:Sn = 3.3:1.0:1.0; 450°C; 28 d; Ni-tube] colourless, monoclinic single crystals of Cs₄[SnO₄] have been yielded for the first time: space group P2₁/c with a = 1180.8 pm. b = 728.2 pm, c = 1166,7 pm, β = 111.79°, Z = 4. The crystal structure was solved by fourcycle-diffractometer data [Siemens AED2, 2299 from 2708 I₀(hkl), R = 7.0%, R_w = 5.6%], parameters see text. Characteristic for the complicated structure are “isolated” [SnO₄]^4? tetrahedra. Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN and the Madelung Part of Lattice Energy, MAPLE, have been calculated.     

Reaktionen von Uranpentabromid Die Kristallstrukturen von PPh4[UBr6], PPh4 [UBr6] · 2CCl4, (PPh4)2[UBr6] · 4CH3CN und (PPh4)2[UO2Br4] · 2CH2Cl2

Reactions of Uranium Pentabromide. Crystal Structures of PPh₄[UBr₆], PPh₄[UBr₆] · 2CCl₄, (PPh₄)₂[UBr₆] · 4CH₃CN, and (PPh₄)₂[UO₂Br₄] · 2CH₂Cl₂ PPh₄[UBr₆] and PPh₄[UBr₆] · 2CCl₄ were obtained from UBr₅ · CH₃CN and tetraphenylphosphonium bromide in dichloromethane, the latter being precipitated by CCl₄. Their crystal structures were determined by X-ray diffraction. PPh₄[UBr₆]: 2101 observed reflexions, R = 0.090, space group C2/c, Z = 4, a = 2315.5, b = 695.0, c = 1805.2 pm, β = 96.38°. PPh₄[UBr₆] · 2CCl₄: 2973 reflexions, R = 0.074, space group P2₁/c, Z = 4, a = 1111.5, b = 2114.2, c = 1718.7 pm, β = 95.42°. Hydrogen sulfide reduces uranium pentabromide to uranium tetrabromide. Upon evaporation, bromide is evolved from solutions of UBr₅ with 1 or more then 3 mol equivalents of acetonitrile in dichlormethane yielding UBr₄ · CH₃CN and UBr₄ · 3CH₃CN, respectively. These react with PPh₄Br in acetonitrile affording (PPh₄)₂[UBr₆] · 4CH₃CN, the crystal structure of which was determined: 2663 reflexions, R = 0.050, space group P2₁/c, Z = 2, a = 981.8, b = 2010.1, c = 1549.3 pm, β = 98.79°. By reduction of uranium pentabromide with tetraethylammonium hydrogen sulfide in dichloromethane (NEt₄)₂[U₂Br₁₀] was obtained; (PPh₄)₂[U₂Br₁₀] formed from UBr₄ and PPh₄Br in CH₂Cl₂. Both compounds are extremely sensitive towards moisture and oxygen. The crystal structure of the oxydation product of the latter compound, (PPh₄)₂[U0₂Br₄]· 2 CH₂Cl₂, was determined: 2163 reflexions, R = 0.083, space group C2/c, Z = 4, a = 2006.3, b = 1320.6, c = 2042,5 pm, β = 98.78°. Mean values for the UBr bond lengths in the octahedral anions are 266.2 pm for UBr₆-, 276.7 pm for UBr₆^2? and 282.5 pm for UO₂Br₄^2?