Synthese und Kristallstruktur von Tetramethylammonium-Sodalith

Tetramethylammonium sodalite, a synthetic species of composition (CH₃)₄NAlSi₅O₁₂, has been obtained in good yield under hydrothermal conditions in the absence of metal cations. Its crystal structure has been determined using accurate powder data since single crystals could not be grown. The structure seems to be body-centered cubic with a = 8.975 Å but the true symmetry is non-cubic (probable space group I4 ). Each cage of the aluminosilicate framework contains one tetramethylammonium ion. The organic cation does not conform to the cubic symmetry of the ideal framework. The methyl groups point to oxygen atoms of the framework, and the short methyl-oxygen distances of 3.06 Å indicate strong C? H … O interaction. The present results indicate beyond doubt that C? H … O hydrogen bonding involving methyl groups can occur in silicates. This is of particular significance in zeolite chemistry and in the interpretation of interlayer distances in organic clay complexes.     

Darstellung und Kristallstruktur von HfOS

Synthesis and Crystal Structure of HfOS On attempts to prepare binary and ternary hafnium sulfides a small quantity of single crystals was obtained which could be identified as HfOS. The new compound is cubic, space group P2₁3 with a = 5.6824(6) Å. It is isostructural with the cubic form o ZrOS. In order to refine the structure parameters intensity measurements were carried out by means of a four-circle single crystal diffractometer.     

Synthese und Kristallstruktur von KMnP und KMnAs

Synthesis and Crystal Structure of KMnP and KMnAs KMnP and KMnAs have been prepared from the elements at 800-°C in a closed system. X-ray investigations suggest a layer-type structure where the manganese atoms are tetrahedrally coordinated by the phosphorus or arsenic atoms. The coordination polyhedra share common edges in two dimensions. The compounds crystallize in the space group P4/nmm with a = 4.275, c = 7.668 Å for KMnP and a = 4.391, c = 7.791 Å for KMnAs, respectively; z = 2. The structural relations to the ternary arsenides with transition metals and lithium, t o Mn₂As, to the oxidehalides of the lanthanides and to ternary sulfides are discussed.     

Molekular- und Kristallstruktur von Tetramethylcyclodisilthian

Molecular and Crystal Structure of Tetramethylcyclodisilthiane The molecular and crystal structure of the title compound (I) has been determined by X-ray diffraction. The Si₂S₂-tetracycle is planar with Si? S bond length of 2.152(2) Å and bond angles SiSSi smaller then SSiS (82.46(6) and 97.54(7)°).     

Synthese und Kristallstruktur von N-Formylformamidinium-hexachloroantimonat

Synthesis and X-Ray Structure Determination of N-Formylformamidinium Hexachloroantimonate The title compound is formed in high yields by the interaction of [Cl₂CH? NH? CH?NH₂][SbCl₆] with SO₂ in CH₂Cl₂ solution. According to the spectra (i.r. and ¹H-n.m.r.) the cation [O?CH? NH? CH?NH₂]⁺ exists in an almost planar, all-cisoide conformation. The hexachloroantimonate crystallizes in the orthorhombic space group Pna2₁ with 4 formula units per cell. The anion-cation cross-linkage by relative short NH…?Cl(Sb) bridges is remarkable. The structure was refined to an R value of 0.027.     

Synthese und Kristallstruktur von Tetramethylammonium-Gismondin

A new synthetic zeolite, (CH₃)₄NA1Si₃O₈, H₂O, has been synthesized and shown to be an isotype of the mineral gismondine, CaAl₂Si₂O₈,4H₂O. Sodium and other cations can be introduced by ion exchange after thermal decomposition of the organic cation. A continuous structural change to «cubic» NaP has thereby been recorded, which indicates that the latter is also based on a gismondine-type aluminosilicate framework. The crystal structure of tetramethylammonium-gismondine has been determined using X-ray powder data supplemented by electron diffraction. The crystals are tetragonal, a = 9.84 and c = 10.02 Å, with 4 formula units per unit cell. The apparent symmetry of the framework structure is I4₁/amd, however, this is violated by the organic cation. Two of the methyl groups are pointing to oxygen atoms of the framework and the short methyl-oxygen distances indicate C? H ? O interaction.     

Darstellung und Kristallstruktur von CsTe4

Preparation and Crystal Structure of CsTe₄ CsTe₄ results from a melting reaction at 570°C in sealed quartztubes. The starting materials Cs and Te in the molar ratio 1:4 are produced in a first step by controlled decomposition of the CsN₃ from mixtures of CsN₃ and Te (1:4) at 350°C. CsTe₄ is monoclinic, space group P2₁/c, with a = 7.857(1) Å, b = 7.286(1) Å, c = 14.155(2) Å, β = 93.83(1)°, and Z = 4. The tellurium atoms form a two-dimensional puckered layer built of from pseudo-trigonal-bipyramidal, T-shaped units Te₄^?. The central tellurium atom of this unit may be considered as a pseudo iodine. The compound is compared with other tellurides MTe_n having some like that unexpected principles of connection.     

Synthese und Kristallstruktur von LiHSO4

Synthesis and Crystal Structure of LiHSO₄ Single crystals of the new compound LiHSO₄ are synthezised from the system Lithiumsulfate/Sulfuric acid. The up to day not determined structure of the title compound is monoclinic, space group P2₁/c with the lattice constants a = 5.234(2), b = 7.322(1) and c = 8.363(1) Å, b? = 90.02(2)°. The volume of the unit cell has been determined to V = 320.5 ų, the number of formula units to Z = 4 and the density to D_x = 2.156 g cm^?3. There are crystallographically identical SO₃(OH)- and LiO₄-tetrahedra in the structure. Every tetraheda is linked to four different tetrahedra of the other sort. Two neighboured LiO4 terahedra form a common edge. In that way layers are formed running parallel the yz-plane. These layers are connected over hydrogen bonds.     

Synthese und Kristallstruktur von KTeOF3

Synthesis and Crystal Structure of KTeOF₃ KTeOF₃ has been synthesized by solid state reaction of KF, TeO₂ and KTeF₅ in equimolar amounts. Its crystal structure has been solved by single crystal structure analysis (P4₂/n, a = 1007.96(3), c = 789.58(3) pm, Z = 8, R₁ = 0.0311). As a characteristic feature, the compound contains unprecedented dimeric anions Te₂O₂F₆^2– formed by two edge‐sharing pseudo‐octahedral units. IR and Raman data are given.     

Darstellung und Kristallstruktur von KSbS2

Preparation and Crystal Structure of KSbS₂ Red KSbS₂ was prepared in a aqueous solution of KHS and Sb₂S₃ under mild hydrothermal conditions. For crystallographic data see ?Inhaltsübersicht”?. There are SbS-chains, built up by ψ-trigonal bipyramids, which are connected by sharing edges. The K⁺-Ions between these chains have a nearly octaedric coordination.     

Synthese und Kristallstruktur von CaBiVO5

Synthesis and Crystal Structure of CaBiVO₅ Single crystals of the hitherto unknown compound CaBiVO₅ were prepared and investigated by X-ray work. It crystallizes with orthorhombic symmetry, space group D? Pbca, a = 11.2022, b = 5.4283, c = 15.5605 Å, Z = 8. The crystal structure is characterized by layers of the edge-linked CaO₇ polyhedra, isolated VO₄ tetrahedra and an asymmetric surrounding of Bi³⁺ by oxygen.     

Darstellung und Kristallstruktur von CsBO2

Preparation and Crystal Structure of CsBO₂ Colourless single crystals of CsBO₂ have been prepared from intimate mixtures of CsO_0.57 and B₂O₃ (Cs:B = 3.2:1.0; 600°C, 38 d). The structure determination from fourcircle diffractometer data (MoK, 443 I_o (h k l), R = 3.1%, R_w = 2.0%) confirms the isotypy with NaBO₂ and KBO₂: space group R 3 c; a = 1 363.7(2) pm, c = 836.5(2) pm; Z = 18. A characteristic structure unit is the planar cyclic anion [B₃O₆]^3?. 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.     

Synthese und Kristallstruktur von BaVo2,5

Single crystals of BaVO_2,5 were prepared by high temperature LASER-technique under a hydrogen atmosphere. The X-ray investigation leads to a trigonal symmetry (a=571.8;c=1161.3 pm, space group C _3v ¹ -P3m 1). BaVO_2,5 consists of a closest sphere packing of oxygen with a sequence of cubic and hexagonal layers of the type ... ccchh ... The consequences in respect to the coordination of Ba²⁺ and V³⁺ are discussed.

     

Darstellung und eigenschaften von diphenylalkylthio- und diphenylarylthio-gallanen. Kristallstruktur von diphenylethylthiogallan

Triphenylgallane reacts with alkyl- and aryl-thiols, respectively, with formation of the corresponding diphenylalkyl- and diphenylaryl-thiogallanes. Spectra and some physical and chemical properties of the new compounds are given. The results of the X-ray structure determination of diphenylethylthiogallane are discussed.     

Darstellung und Kristallstruktur von Calciumimid,CaNH

Synthesis and Crystal Structure of Calcium Imide, CaNH Single-crystals of calcium imide were obtained for the first time by the reaction of a mixture of calcium amide with sodium amide at 850°C in an autoclave for salt melts. After cooling the autoclave to room temperature the crystals are embedded in solid Na which was extracted by liquid ammonia. The structure of calcium imide was determined from single-crystal diffractometer data: space group Fm3 m, Z = 4, a = 5.143(1) Å, R/R_w = 0.032/0.028 mit N(F ${}_{\text{º}}^{\text{2}}$ ? 3σ(F ${}_{\text{º}}^{\text{2}}$ )) = 26, N(Var.) = 5. Ca and N atoms are arranged in the motif of the NaCl structure type. The hydrogen atoms of the imide groups are disordered within the Ca octahedra, and they occupy a six fold split position.     

Die Kristallstruktur und absolute Konfiguration von Mikrolin

The Crystal Structure and Absolute Configuration of Mikrolin. The crystal structure and absolute configuration of mikrolin has been determined by X-ray diffraction. Crystals of mikrolin belong to space group P2₁2₁2₁ with a = 17.867, b = 7.947, c = 9.824 Å, Z = 4. The structure was solved by multi-solution method, and refined to R = 0.060. The anomalous scattering of CuKα-radiation by chlorine was used to determine the absolute configuration of the molecule.     

Darstellung und Kristallstruktur von Lithiumhydrogensulfid,LiHS

Preparation and Crystal Structure of Lithiumhydrogensulfide, LiHS Lithiumhydrogensulfide, LiHS, is prepared from lithiumamide, LiNH₂, by reaction with liquid hydrogensulfide. At 150°C the solubility of LiHS in H₂S is sufficient for the growth of single crystals in a temperature gradient within the autoclaves used. The X-ray structure determination at 295 K is characterized by the following data: Lithium occupies tetrahedral sites in a distorted cubic close-packed arrangement of S; in PtS sulfur occupies tetrahedral sites in a similar way in a distorted close packing of Pt. Hydrogen atoms of the HS^??ions are dynamically disordered in a split position linearly bound to S. At 228 K a thermal effect occurs in DSC-measurements indicating that below this temperature the HS^??ion has fixed positions.     

Darstellung,Kristallstruktur und Eigenschaften von Kaliumhydrogencyanamid

Preparation, Crystal Structure, and Properties of Potassium Hydrogen Cyanamide For the preparation of KHCN₂ melamine has been reacted with potassium amide in liquid ammonia. After evaporation of the solvent the resulting solid has been transformed at 210°C. KHCN₂ (P2₁2₁2₁, a = 708.7(2), b = 909.0(2), c = 901.4(2) pm, Z = 8, R = 0.039, wR = 0.016) is yielded as a coarse crystalline product. In the solid K⁺ and HCN ions occur. As expected two significantly differing bond-distances C? N (117.3(5) pm) and HN? C (128.7(5) pm) have been found in the anion. According to IR-spectroscopy a non linear group N? C? N (174.4(4)°) is observed.     

Kristallstruktur und absolute Konfiguration von (+)-Meloscin-Nb-methobromid

The crystal structure of the N_b-methobromid of the alcaloid meloscin has been determined by three-dimensional X-ray crystallographic methods. The crystals belong to the orthorhombic space group P2₁2₁2₁ with four molecules per unit cell. The cell constants are a = 10.01, b = 17.79, c = 11.43 Å. The absolute configuration has been obtained by the use of anomalous dispersion effects.