Die Kristallstruktur von Kaliummonomethylcarbonat

Crystal Structure of Potassium Monomethylcarbonate Potassium monomethylcarbonate KCH₃CO₃ was obtained from reaction of dimethylcarbonate with potassium hydroxide in methanole. The crystal structure was determined (triclinic, P1 (no. 2), Z = 2, a = 380.9(2) pm, b = 558.9(3) pm, c = 985.3(3) pm, α = 100.71(2)°, β = 90.06(3)°, γ = 92.48(3)°, V = 205.9(2) · 10⁶ pm³, wR(F²) = 0.054, wR_obs(F) = 0.022). Structural relations between potassium monomethylcarbonate and potassium hydrogencarbonate are discussed.     

Die Kristallstruktur von PrTe2

The Crystal Structure of PrTe₂ X‐ray diffraction single‐crystal structure analysis of PrTe₂ prepared by chemical vapour transport reactions starting with praseodymium and tellurium in the presence of trace amounts of iodine also revealed superstructure reflections indicating just as for CeTe₂ a (2 × 2 × 2)‐supercell of the basic anti‐Fe₂As‐type structure instead of a (2 × 2 × 1)‐supercell as for LaTe₂. In contrast to LaTe₂ with monoclinic symmetry (space group P1c1), PrTe₂ crystallizes tetragonal in the space group P4 with the lattice parameters a = 896.80(5) pm and c = 1811.9(1) pm (Z = 16). The doubling of the c‐lattice parameter compared to LaTe₂ is observed due to different polyanionic structural motifs in the heights z ≈ 0 and z ≈ ¹/₂. These are a herringbone pattern of [Te₂] dumbbell pairs (motif A; a topology which is also found in LaTe₂), isolated square four‐membered [Te₄] rings in z ≈ 0 (motif B) and additionally rectangular four‐membered [Te₄] rings in z ≈ ¹/₂ (motif C). Though CeTe₂ and PrTe₂ are crystallizing isotypically, there are distinct differences in the interatomic distances within the polyanionic Te layers and resulting from these also a different topology of the structural motif C. The individual structural elements are causing a diffraction pattern, which is all in all to be explained by a statistical superposition of the different elements in form of microdomains.     

Die Kristallstruktur von Bortriiodid,BI3

Crystal Structure of Boron Triiodide, BI₃ Boron triiodide as a micro‐crystalline powder was obtained after sublimation of the reaction product of NaBH₄ and iodine. An X‐ray powder diagram of the temperature‐, air‐, and light‐sensitive compound was collected at –73 °C. According to the results of the Rietveld refinement, the crystal structure of BI₃ is isotypic to that of BCl₃ (space group P6₃/m, no. 176, a = 699.09(2), c = 736.42(3) pm). The B–I bond length was determined to be 211.2(8) pm.     

Die Kristallstruktur von AgIIF[AgIIIF4]

Crystal structure of Ag^IIF[Ag^IIIF4] For the first time dark brown single crystals of mixedvalent AgF[AgF₄] were isolated under solvothermal conditions out of anhydrous HF/F₂. The compound crystallizes in a new type of structure, triclinic with a = 499.9(2) pm, b = 1108.7(5) pm, c = 735.7(3) pm, α = 90.05(3)°, β = 106.54(4)°, γ = 90.18(4)°, spcgr. P1¯ — C_i¹ (No. 2) and Z = 4.     

Die Kristallstruktur der Tieftemperaturmodifikation von Ag5Te2Cl

The Crystal Structure of the Low‐Temperature Form of Ag₅Te₂Cl Crystals of trimorphic Ag₅Te₂Cl were obtained by solid state reaction from a stoichiometric mixture of silver, tellurium, and tellurium(IV)chloride (480 °C, 4–10 days). The crystals were cooled down to –80 °C without decomposition and data collection was carried out at this temperature. The low temperature form of the title compound crystallizes in space group P2₁/c with lattice constants of a = 19.359(1) Å, b = 7.713(1) Å, c = 19.533(1) Å, β = 90.6°(1), V = 2916.4(1), and Z = 16. The refinement converged to residual values of R₁ = 0.0381 and wR₂ = 0.0847, respectively. Te and Cl atoms form empty, distorted octahedra interconnected by common vertices to give a 3D‐network. Ag atoms form clusters with Ag–Ag distances between 2.83 Å and 3.10 Å.     

Die Kristallstruktur von KPr3Te8

Crystal Structure of KPr₃Te₈ Out of the compounds ALn₃Q₄ (A = Na, K, Rb, Cs; Ln = Lanthanoid; Q = S, Se and Te) the crystal structure of the telluride KPr₃Te₈ was determined by X‐ray single‐crystal structure analysis. Single crystals of the compound were synthesized by a flux technique with K₂Te₃ as flux after separation of the K₂Te₃ excess by extraction with absolute dimethylformamide (DMF). The compound crystallizes monoclinically in space group P12₁/c1 with the lattice parameters a = 1390.58(7) pm, b = 1291.06(6) pm, c = 900, 18(5) pm and β = 99, 264(6)° isotypically to KNd₃Te₈. Characteristics in the crystal structure of KPr₃Te₈ are L‐shaped units of three tellurium atoms [Te₃]^2— as well as infinite zig‐zag chains of tellurium atoms [Te₄]^4—. The shortest interatomic distances in the chain are alternating only slightly with 298 and 300 pm and are in the range of partial bonds. Both structure elements are arranged in almost planar layers and are interconnected with each other by secondary interactions revealing interatomic distances in the range of 327 to 349 pm. The crystal structure of KPr₃Te₈ can be regarded as a addition‐defect variant of the binary NdTe₃ structure type. This finding is illustrated by group‐subgroup relations in form of a so called Bärnighausen family tree.     

Synthese und Kristallstruktur von Ba6ZnIn2Cl20

Synthesis and Crystal Structure of Ba₆ZnIn₂Cl₂₀ Colourless single crystals of Ba₆ZnIn₂Cl₂₀ are obtained from a 6 : 3 : 2 molar mixture of BaCl₂, ZnCl₂ and InCl₃ at 420 °C in a Pyrex ampoule. It crystallizes with the monoclinic space group P2₁/c (Z = 4) with a = 1957.8(2), b = 1014.69(8), c = 1778.7(2) pm, β = 110.94(1)°, in a new structure. Zn²⁺ is surrounded tetrahedrally and In³⁺ octahedrally by chloride ions. Half of the [InCl₆] octahedra are isolated from each other, the other half shares common edges to form [In₂Cl₁₀] double octahedra. Ba²⁺ has coordination numbers of eight and nine. There are chloride ions that do not belong to Zn²⁺ or In³⁺ so that the formula may be written as Ba₁₂Cl₁₀[ZnCl₄]₂[InCl₆]₂[In₂Cl₁₀].     

Die Kristallstruktur des Calciumazid-Dihydrates

Single crystals of Ca(N₃)₂·2 H₂O have been prepared from aqueous solutions at room temperature. The crystals are monoclinic,a=1 159.0 (3),b=614.2 (2),c=785.5 (2) pm, =106.52 (2)°,Z=4, space group P2₁/n. The crystal structure was determined by single crystal X-ray diffraction (1 109 Mo-K-reflexions,R=0.052). Calcium atoms are surrounded by four azide groups and four water molecules. The coordination polyhedra are antiprism which are sharing azide groups and water molecules to form layers. The lattice constants and powder pattern agree well with values reported earlier for Ca(N₃)₂ · 1.5 H₂O [1]. It was also shown, that Sr(N₃)₂ · 2 H₂O is isotypic with Ca(N₃)₂ · 2 H₂O.

     

Kristallstruktur von Natriumoxidsulfat

Crystal Structure of Sodium Oxide Sulfate Na₆O(SO₄)₂ was prepared from a mixture of Na₂O and Na₂SO₄ by solid state reaction at 500 °C in silver crucibles. Its crystal structure (Fm 3 m, a = 967.7(1) pm, Z = 4, R1 = 0.060, wR2 = 0.1364) can be derived from the fluorite type of structure and corresponds to the anti‐Pentlandite type.     

Kristallstruktur von wasserfreiem Na2HPO4

Crystal Structure of Anhydrous Na₂HPO₄ Na₂HPO₄ crystallizes monoclinic in P2₁/m? C with: a = 545.(1), b = 684.7(2); c = 547.3(1) pm; β = 116.34(1)°; Z = 2. The structure consists of a nearly hexagonal close-packed arrangement of HPO₄^2? anions with Na⁺ in the “octahedral” and “tetrahedral” holes. The anions are orientationally disordered. Structural relationships with Na₂SO₄(III) and the glaserite-type of structure are discussed.     

Die Kristallstruktur von Cs5Eu(N3)8

Summary The crystal structure of pentacesium octaazidoeuropiate(III), Cs₅Eu(N₃)₈, was determined by single crystal X-ray diffraction: orthorhombic,a=16.811(4),b=16.860(5),c=16.964(3)Å, space group Pbca,Z=8, 2 310 observed reflections,R=0.048. Europium atoms are coordinated to eight azide groups, the coordination polyhedra have no azide groups in common. Four cesium atoms are surrounded by eight, one by seven azide groups. The azide groups are symmetric with mean N-N-distances of 1.17(1)Å.

     

Synthese und Kristallstruktur des ionischen Tellurnitridchlorids [Te3N2Cl5(SbCl5)]+SbCl6−

Synthesis and Crystal Structure of the Ionic Tellurium Nitride Chloride[Te₃N₂Cl₅(SbCl₅)]⁺SbCl₆^? The title compound has been prepared by the reaction of Te₂NCl₅ with antimony pentachloride in CH₂Cl₂ suspension. It is characterized by IR spectroscopy and by a crystal structure determination. Space group P2₁/c, Z = 4, lattice dimensions at ?70°C: a = 1535.6, b = 1259.5, c = 1572.4 pm, β = 109.30°, R = 0.031. The compound forms an ionic pair with the central group of a (TeNCl)₂ molecule in which the tellurium atoms are linked by the nitrogen atoms to give a planar Te₂N₂ four-membered ring. One of the nitrogen atoms is coordinated by a TeCl₃⁺ unit, the other one by an antimony pentachloride molecule. According to the IR spectra a structure like [Te₂N₂Cl₂(TeCl₄)₂] is proposed for Te₂NCl₅.     

Kristallstruktur von Caesiumacetat,Cs(CH3COO)

Crystal Structure of Cesium Acetate, Cs(CH₃COO) . The crystal structure of cesium acetate, Cs(CH₃COO), was determined from single crystal fourcirclediffractometer data: hexagonal crystal system, P6/m (No. 175), Z = 6, a = 1 488.0(2), c = 397.65(5) pm, V_m = 76.54(2) cm³/mol, R = 0.045, R_w = 0.030. The structure consists of flat layers of acetate anions parallel (001) that are separated by layers of cesium cations. There is a close relationship with the CaF₂ type according to CsO₂(CCH₃): each cesium cation has eight oxygen atoms as nearest neighbours. They form a heavily distorted cube with trapezoidal basal faces. In contrast to CaF₂, these polyhedra are linked via three faces and two edges to a three-dimensional network.     

Zur Kristallstruktur von CaFeF5

On the Crystal Structure of CaFeF₅ Single crystals of CaFeF₅ were obtained by heating a mixture of the component fluorides at 860°C for 12 d (a = 549.2(1), b = 1007.6(2), c = 759.9(2) pm, β = 110.02(3)°; space group P2₁/c, Z = 4). The X‐ray structure redetermination of a twinned specimen confirmed the chain structure of octahedra sharing trans corners already known. But the anomalies reported earlier were removed and less distorted [FeF₆] octahedra and [CaF₇] pentagonal bipyramids were found, the distances of which are split within the usual range around mean values of Fe—F: 192.4 and Ca—F: 233.1 pm.     

Synthese und Kristallstruktur des Tellur-Nitridchlorids [Te11N6Cl26]

Synthesis and Crystal Structure of the Tellurium Nitride Chloride [Te₁₁N₆Cl₂₆] The title compound has been prepared by the reaction of tellurium tetrachloride with tris(trimethylsilyl)amine in boiling toluene. Pale yellow crystals of the composition [Te₁₁N₆Cl₂₆]₂ · 9C₇H₈ are obtained by cooling of the saturated solution. The compound was characterized by IR spectroscopy and by a crystal structure determination. Space group P1 , Z = 1, structure solution with 5912 observed unique reflections, R = 0.043. Lattice dimensions at ?50°C: a = 1636.2, b = 1692.7, c = 1704.1 pm, α = 60.57°, β = 69.59°, γ = 64.29°. The dominating structural element of the nitrchloride are planar Te₅N₃ units forming two four-member Te₂N₂ rings which are condensed together. Two asymmetric units [Te₁₁N₆Cl₂₆] are linked by a centre of symmetry; the intercalated toluene molecules are without binding interactions.     

Kristallstruktur von Morpholinium-2,3-dicyano-hydrochinolat

Summary On deprotonation of 2,3-dicyano-p-hydroquinone by morpholine, a network of hydrogen bonds is formed in which the chains of hydroquinone monoanions are connected by strongerN-H...O and by weakN-H...N bondsvia the morpholinium nitrogens.

     

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.

     

Darstellung und Kristallstruktur eines Calciumcarbidchlorides mit einer C34−-Einheit,Ca3Cl2C3

Synthesis and Crystal Structure of a Calciumcarbide Chloride Containing a C₃^4? Unit, Ca₃Cl₂C₃ Ca₃Cl₂C₃ was prepared from calcium, CaCl₂ and graphite in sealed tantalum capsules. Red, transparent crystals were obtained from heating the mixture to 900°C (for one day) and annealing afterwards at 780°C for three days. The compound forms a layered structure (Cmcm, Z = 4, a = 384.24(9) pm, b = 1340.7(3) pm, c = 1152.6(3) pm, R = R_W = 0.036 for 481 independent intensities) with alternating stacks of double layers of Ca²⁺ and monolayers of Cl^?. The double layers of calcium contain allylenide ions, C₃^4?. The latter exhibit C_2v symmetry, a bond angle (C? C? C) of 169.0(6)° and a C? C separation of 134.6(4) pm.     

Neubestimmung der Kristallstruktur von NbOCl3

NbOCl₃ was obtained from a reaction of NbCl₅ and Nb₂O₅ at 260?C. Contrary to the literature data, NbOCl₃ crystallizes in the non‐centrosymmetric space group P&4macr;2₁m as determined by single‐crystal and powder X‐ray diffraction data (crystal: a = b = 1089.59(6) pm, c = 394.79(2) pm, Z = 4, R₁ = 0.0229, wR₂ = 0.0459, powder: a = b = 1086.36(6) pm, c = 393.65(2) pm). The niobium atoms are surrounded by distorted octahedra built of four chlorine atoms and two oxygen atoms in trans positions. Two such octahedra are edge‐bridged through shared chlorine atoms, forming dimers. These units are linked to each other by apical oxygen atoms forming one‐dimensional Nb₂Cl₆O₂ chains parallel [001]. Contrary to the literature data two different Nb‐O distances are obtained.     

Die Kristallstruktur von K[F5W(≡NCl)]

Crystal Structure of K[F₅W(≡NCl)] Orange single crystals of K[F₅W(≡NCl)] have been formed as a by‐product from the reaction of tungsten nitrido chloride, WNCl₃, with Me₃SnF in the presence of potassium fluoride in toluene suspension. K[F₅W(≡NCl)] crystallizes in the monoclinic space group P2₁/c with four formula units per unit cell. Lattice dimensions at –83 °C: a = 1145.9(3), b = 770.4(2), c = 772.5(2) pm, β = 99.91(1)°, R₁ = 0.0742. The compound forms an ionic structure with octahedral [F₅W(≡NCl)]^– ions with a nearly linear arrangement of the N‐chloroimido ligand group W≡N–Cl (bond angle 173°, WN distance 174 pm). The K⁺ ions link the anions via K…F contacts and coordination number eight to form double layers along [100]. The layers itself are associated by short bounding Cl…F contacts of 279 pm.