Die Substituierbarkeit von Blei in Pb3Ge2O7 durch Cd,Sr und Ba

Up to 25% of the lead atoms can be substituted by Sr in Pb₃Ge₂O₇ without change in structure. The existence of Pb₈Cd(Ge₂O₇)₃ with the structure of barysilit has been confirmed in accordance with the literature. A new phase with barysilitstructure was observed in the system BaO/PbO/GeO₂.

     

Die Kristallstruktur der Verbindung Li2ZnGeO4

The crystal structure of dilithiumzine orthogermanate, Li₂ZnGeO₄, has been determined and refined byFourier syntheses and least-squares, using three dimensional single-crystal data. A finalR-value of 5.7% was obtained. The monoclinic unit cell (Pn–C_s ²) with the dimensionsa=6.40,b=5.45,c=5.04 Å and =90.2° contains two formula units Li₂ZnGeO₄. The crystal structure is built up by [GeO₄] tetrahedra, which are linked together by [LiO₄] and [ZnO₄] tetrahedra. The average interatomic distances are found to be: Ge–O=1.77, Li–O=2.01 and Zn–O=1.93 Å.     

Die Kristallstrukturen der Hydroxyhalogenide Li4(OH)3Br und Li4(OH)3I

The Crystal Structures of the Lithium Hydroxide Halides Li₄(OH)₃Br and Li₄(OH)₃I Using single crystal analysis and powder diffraction data the crystal structures of the lithium hydroxide halides Li₄(OH)₃Br and Li₄(OH)₃I were solved and refined. Li₄(OH)₃Br crystallises in the space group P2₁/m and is isotypic with the lighter homologue Li₄(OH)₃Cl. (Rietveld‐refinement; T = 293 K; a = 545, 41(1); b = 758, 13(1); c = 650, 20(1) pm; β = 93, 82(1)°; Z = 2; 300 unique reflections; R_p = 0, 106; R_wp = 0, 109; R_exp = 0, 081). Li₄(OH)₃I crystallises in the space group Pmmn in a variant of the LiOH structure in which 1/4 of the hydroxide anions are replaced by iodide anions. (Single crystal analysis; T = 100 K; a = 1029, 5(4); b = 525, 9(2); c = 573, 2(2) pm; Z = 2; 392 unique reflections; R₁ = 0, 0642).     

Die Kristallstruktur von TlFe3Te3

TlFe₃Te₃ is hexagonal, space groupP6₃/m–C _2h ⁶ ,a=9.350(2) Å,c=4.2230 (7) Å,Z=2. Iron and tellurium atoms occupy the positions 6 (h) withx=0.170,y=0.149 andx=0.046,y=0.357 respectively. Thallium atoms are situated in 2 (d). The structure was determined on the basis of single crystal data obtained form a four circle diffractometer. Refinement yielded andR-value of 4.8% for an asymmetric set of 267 reflections. TlFe₃Te₃ is a new structure type. The structure and its relations to the Mn₅Si_3–, the Nb₃Te₄-and the Tl _x V₆S₈-type are discussed.

     

Die Kristallstruktur des Natriumorthogermanats,Na4GeO4

The crystal structure of the title compound has been determined from single crystal X-ray diffraction data and refined toR=0.125. The unit cell is triclinic, space group P, (No. 2),a=5.688(1),b=5.701(1),c=8.583(1) Å, =81.32(1), =71.50(1), =67.95(1)° andZ=2. The structure consists of isolated [GeO₄] tetrahedra linked together by four- and five-coordinate sodium atoms. Na₄GeO₄ is isostructural with Na₄CoO₄ (which has been described to be non-centrosymmetric and for which a centrosymmetric model is presented), K₄GeO₄, K₄SnO₄ and K₄PbO₄.

     

Die Kristallstruktur von TlFeSe2 und TlFeS2

TlFeSe₂ is monoclinic, space groupC2/m–C _2h ³ ,a=11.973 Å,b=5.490 Å,c=7.110 Å, =118.2°,Z=4.TlFeS₂ is isotypic witha=11.636 Å,b=5.304 Å,c=6.799 Å, =116.7°.The crystal structure of TlFeSe₂ has been determined from single crystal diffractometer data. Isotypy of the sulfide has been confirmed from powder diffraction data. The crystal structure containing infinite linear chains of edgesharing FeX ₄-tetrahedra, and its relationship to the thio- and selenoferrates of the alkali metals are discussed. The mineral raguinite is very probably isotypic to synthetic TlFeS₂.

     

Die Kristallstruktur der isotypen Verbindungen KAg(NO3)2, NH4Ag(NO3)2 und RbAg(NO3)2

KAg(NO₃)₂ crystallizes in space group P2₁/a-C _2h ⁵ ,a=13.953,b=4.955,c=8.220 Å, =97.76°,Z=4. X-ray intensities were collected with a two-circle diffractometer. The structure was solved by means of direct methods andFourier syntheses and was refined by the least squares method toR=0.034 with 1346 observed reflexions. ¹ {Ag₂(NO₃)₄}^2–-chains run parallel toy and are linked by potassium ions. Ag shows a distorted tetrahedral coordination with four relatively close O. K is irregularily surrounded by ten O. The isotypic compounds NH₄Ag(NO₃)₂ and RbAg(NO₃)₂ were refined toR=0.032 and 0.035, respectively. The coordination figures are compareable with those in KAg(NO₃)₂.

     

Zur Kristallstruktur von Li3InCl6

Ternary Halides of the A₃MX₆ Type. VIII On the Crystal Structure of Li₃InCl₆ Colorless single crystals of Li₃InCl₆ are obtained from a 3 : 1 molar mixture of LiCl and InCl₃ via Bridgman‐type crystal growth. The crystal structure (monoclinic, C2/m, Z = 2, a = 643.2(3), b = 1109.3(3), c = 639.8(3) pm, β = 109.8(1)° R₁ = 0.0549, wR₂ = 0.1364 (all data) may be derived from the AlCl₃‐type of structure as was previously also found for the bromides Li₃MBr₆ (M = Sm–Lu, Y) and iodides Li₃MI₆ (M = Er–Yb, Y).     

Die Kristallstruktur von Ca9(Ca x Mg1−x )(AsO4)6(AsO3OH) mitx ∼ 0,5

The crystal structure of Ca₉(Ca _x Mg_1–x )(AsO₄)₆(AsO₃OH) withx 0.5 (a=10.73,c=37.74 Å; space group R3c-C _3v ⁶ ;Z=6) was solved from 985 independent X-ray intensities collected on a 4-circle diffractometer, and refined toR=5.7% for all data. This compound is isotypic to Ca₉Mg(PO₄)₆(PO₃OH), a structure of the whitlockite-type.

     

Die Kristallstruktur von Ca2As2O7

The structure of Ca₂As₂O₇ (a ₀=7.05,b ₀=9.30,c ₀=4.89 Å; =101.3°; space groupC2/m-C _2h ³ ;Z=2) has been solved from 465 independent X-ray intensities collected on aWeissenberg-type diffractometer up to anR-factor of 2.4% for all intensities. The structure of Ca₂As₂O₇ represents a further Thortveitite structure type.

     

Motive dichtester Kugelpackungen: Die Verbindungen Zn3(PS4)2 und LiZnPS4

Motifs of Closest Packings: The Compounds Zn₃(PS₄)₂ and LiZnPS₄ The crystal structure of Zn₃(PS₄)₂ was determined by single crystal X‐ray methods. The compound crystallizes tetragonally (P4¯n2; a = 7.823(1), c = 9.053(1)Å; Z = 2) with a new structure type built up by corner‐sharing ZnS₄ tetrahedra, which form two‐dimensional layers. Between them the P atoms are coordinated likewise tetrahedrally by sulfur. The PS₄ tetrahedra are arranged according to the motif of the cubic closest packing with zinc in three quarters of the tetrahedral voids. LiZnPS₄ (I4¯; a = 5.738(1), c = 8.914(1)Å; Z = 2) was synthesized by heating the elements at 400 °C. In comparison with Zn₃(PS₄)₂ one Zn atom is replaced by two Li atoms. The metal atoms are located in the centres of the sulfur tetrahedra in such a way that the unit cell volume is only about half that of the zinc compound. In this packing of the PS₄ units all the tetrahedral voids are occupied by lithium and zinc atoms. Chemical bonding in LiZnPS₄ is discussed by means of the electron localization function ELF.     

Ternäre Lithium-Selten-Erd-Nitrate mit einsamen Nitrationen: Li3[M(NO3)5](NO3) (M = Gd?Lu,Y). Die Kristallstruktur von Li3Er(NO3)6

Ternary Lithium Rare Earth Nitrates with Lonesome Nitrate Ions: Li₃[M(NO₃)₅](NO₃) (M = Gd? Lu, Y). The Crystal Structure of Li₃Er(NO₃)₆ Single crystals of the ternary nitrate Li₃Er(NO₃)₆ are obtained from a solution of “Er(NO₃)₃” in the melt of LiNO₃. In Li₃Er(NO₃)₆ (monoclinic, P2₁/n, Z = 4; a = 776.0(1); b = 748.86(8); c = 2 396(1) pm; β = 90.76(3)°; R1 = 0.0490; wR2 = 0.0792), Er³⁺ is surrounded by five bidentate nitrate ligands yielding the anionic units [Er(NO₃)₅]^2?. These are arranged in the direction of the 2₁ screw axis. Two lonesome NO₃^? ions are in the middle of such a “helix” and are connected by Li⁺ with the anions [Er(NO₃)₅]^2?. The helices are moved against each other by about half of the lattice constant a and are connected by further Li⁺ ions.     

Kristallstruktur des Lithium‐Trimethylsilanolats [Li7(OSiMe3)7(THF)]

The lithium silanolate LiOSiMe₃ is accessible from the reaction of Me₃SiOSiMe₃ with LiMe in tetrahydrofuran. Single crystals of [Li₇(OSiMe₃)₇(THF)] were obtained from toluene at 25 °C. The structure of [Li₇(OSiMe₃)₇(THF)] (C2/c) features a capped trigonal antiprismatic arrangement of seven Li atoms. The Li atoms in [Li₇(OSiMe₃)₇(THF)] are μ₃‐bridged by seven O atoms of the silanolate ligand.     

Die Kristallstruktur von Cu7(OH)6(TeO3)2(SO4)2

The crystal structure of the new phase Cu₇(OH)₆(TeO₃)₂(SO₄)₂ [a=7.389 (1),b=7.638 (1),c=7.662 (2) Å, =75.17 (1), =75.90 (1), =84.19 (1)°;Z=1] was determined by direct methods andFourier summations from X-ray intensities, and was refined in space group P -C _i ¹ toR=0.039. As usual, the Cu(II) atoms are coordinated to four O atoms forming approximately a square with average Cu-O=1.96 (3) Å; one or two more distant O neighbours complete the coordination. The shape of the TeO₃ group is a rather clear-cut trigonal pyramid. A disorder was found for the SO₄ tetrahedra. The compound was synthesized under hydrothermal conditions [500 (10) K, saturation vapour pressure].

Herrn Prof. Dr.K. Komarek zum 60. Geburtstag gewidmet.     

Tetraammin-Lithium-Kationen zur Stabilisierung phenylsubstituierter Zintl-Anionen: Die Verbindung [Li(NH3)4]2[Sn2Ph4]

Tetraammine Lithium Cations Stabilizing Phenylsubstituted Zintl-Anions: The Compound [Li(NH₃)₄]₂[Sn₂Ph₄] Ruby-red, brittle single crystals of [Li(NH₃)₄]₂[Sn₂Ph₄] were synthesized by the reaction of diphenyltin dichloride and metallic lithium in liquid ammonia at ?35°C. The structure was determined from X-ray singlecrystal diffractometer data: Space group, P1 , Z = 1, a = 9.462(2) Å, b = 9.727(2) Å, c = 11.232(2) Å, α = 66.22(3)°, β = 85.78(3)°, γ = 61.83(3)°, R₁ (F ? 4σF) = 5.13%, wR₂ (F₀² ? 4σF) = 10.5%, N(F ? 4σF) = 779, N(Var.) = 163. The compound contains to Sb₂Ph₄ isosteric centres [Sn₂Ph₄]^2? as anions which are connected to rods by lithium cations in distorted tetrahedral coordination by ammonia. These rods are arranged parallel to one another in the b,c-plane, but stacked along [100].     

Verfeinerung der Kristallstruktur des Dicaesium-Tetraazido-Zinkates Cs2Zn(N3)4 und die Kristallstrukturen komplexer Zinkazide

Summary The crystal structure of dicesium-tetraazido-zincate, Cs₂Zn(N₃)₄, has been refined from single crystal X-ray-diffractometer data. The previously reported orthorhombic structure, consisting of isolated Zn(N₃)₄-tetrahedra was confirmed and improved lattice parameters and atomic distances were determined. The azide groups are asymmetric and the coordination of central nitrogen atoms to cesium was observed. A table of structure data and mean atomic distances for fourteen zinc-azide compounds is added and the structures are discussed.

Herrn Prof. Dr. Karl Torkar zum 70. Geburtstag gewidmet     

Kristallstruktur und Infrarot-Absorptionsspektrum von synthetischem Monohydrocalcit,CaCO3·H2O

The crystal structure of synthetic monohydrocalcite was solved withPatterson andFourier syntheses and refined for the subcell withá=6.0931 (9) Å,=7.5446 (18) Å, space group P3₁21 or P3₂21,Z=3 toR _w=0.039. Very weak superstructure reflections define a cell with andc=, space group P3₁ or P3₂,Z=9. The superstructure result from ordering of the CO₃ groups and was refined with rigid carbonate groups toR _w=0.086. The interpretation of the IR spectrum is in agreement with the results of the X-ray structure analysis.

     

Preparation and Crystal Structure of Li4[TaN3]

The new lithium nitridotantalate(V), Li₄[TaN₃], was prepared by reaction of Li₁₅[CrN₄]₂N with the wall of a welded Ta ampoule in the presence of metallic Li at 1470 K. Li₄[TaN₃] forms colourless single crystals (platelets, space group Ibca, No. 73, a = 491.85(4) pm, b = 973.59(6) pm, c = 1415.0(1) pm, Z = 8, R1 = 0.0288). The crystal structure is described as Li₂O superstructure with ordered occupation of the tetrahedral sites by Li and Ta. The resulting arrangement leads to infinite chains [TaN₂N_2/2^4—] running along [100].     

ChemInform Abstract: The First Oxogermanate with “Stuffed Pyrgoms”: CsNa3Li8(Li(GeO4))4.

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