Die Kristallstruktur des Bleimonohydrogentriphosphats,Pb2HP3O10

Crystal Structure of Lead Monohydrogentriphosphate, Pb₂HP₃O₁₀ By heating of Pb₂P₄O₁₂ · 2 H₂O at 150°C crystalline Pb₂HP₃O₁₀ is formed topotactically. In these crystals amorphous H₃PO₄ is included. The monoclinic crystals are fourfold twinned. Space group: Cm; unit cell: a = 6.93 ± 0.01, b = 14.34 ± 0.01, c = 5.97 ± 0.01 Å, β = 135.1 ± 0.1°. The crystal structure was determined by heavy-atom method and refined by least-squares calculations. The P₃O₁₀^5? anion consists of three PO₄ tetrahedra connected by common oxygen atoms. The chain has mirror symmetry across a plane passing the middle P atom. Lead is coordinated by eight oxygen atoms. The polyhedra of Pb are connected parallel y and z by common edges. Six P₃O₁₀^5? chains are joined by one lead ion.     

Die Kristallstruktur von LiEu3O4

The crystal structure of LiEu₃O₄ which represents a new structure type was solved by usual methods with the aid of integrated WEISSENBERG photographs (MoK_α radiation, 787 reflexions) and refined to a reliability index of 4.3%. In LiEu₃O₄ just as in the first known europium(II, III)-oxide, Eu₃O₄, a clear distinction is possible between the divalent and trivalent europium ions. The given assignment which is based on crystal chemical arguments has been verified indirectly by means of the isostructural compound LiSr₂EuO₄, the cation distribution of which was established experimentally. The structure of LiEu₃O₄ is discussed in connection with the related oxides EuO and Eu₃O₄. The geometrical relations to the latter are of special interest, as LiEu₃O₄ undergoes a topotactical transformation into Eu₃O₄ by heating it in a high vacuum. There is an astonishing close structural relationship between LiEu₃O₄ and Yb₃S₄: except for lithium all the atoms are correlated as for isostructural compounds.     

Die Kristallstruktur von Rb6Si10O23

Zusammenfassung Die Kristallstruktur der Verbindung Rb₆Si₁₀O₂₃ (bisher als Rb₂Si₄O₉ beschrieben) wurde mit Hilfe dreidimensionaler Röntgendaten bestimmt und bis zu einemR-Wert von 0,078 verfeinert. Die Gitterparameter der rhombischen Elementarzelle (C2mm-C _2v ¹⁴ ) betragen:a=9,348,b=16,290 undc=8,055 Å. Die Struktur besitzt ein dreidimensionales Gerüst aus [SiO₄]-Tetraedern, die sowohl über 4 als auch über 3 Ecken vernetzt vorliegen. Die Anordnung der Tetraeder kann aus der Tridymitstruktur abgeleitet werden und zeigt noch deutlich pseudohexagonale Symmetrie. Bei 500 °C geht die Verbindung in eine Hochtemperaturform mit hexagonaler Symmetrie über (a=9,48 undc=8,16 Å bei 500 °C).

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The crystal structure of Rb₆Si₁₀O₂₃

The crystal structure of the compound Rb₆Si₁₀O₂₃ (identical with Rb₂Si₄O₉) has been determined by means of three-dimensional X-ray data resulting anR-value of 0.078. The lattice parameters of the orthorhombic unit cell (C2mm-C _2v ¹⁴ ) are:a=9.348,b=16.290 andc=8.055 Å. The structure consists of a three-dimensional framework built up by [SiO₄] tetrahedra sharing 4 as well as 3 corners. The arrangement of tetrahedra can be derived from tridymite structure and exhibits pseudohexagonal symmetry. The compound transforms to a high-temperature modification with hexagonal symmetry at 500 °C (a=9.48 andc=8.16 Å).

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Mit 3 Abbildungen     

Die Kristallstruktur von Dicarbonyl-diacetylbis (dimethylhydrazon)-Nickel(O)

Dicarbonyldiacetylbis(dimethylhydrazon)-nickel(O) forms ruby red crystals belonging to the orthorhombic apace group Pbca. The unit cell with lattice constants a = 17.91 Å, b = 10.34 Å and c = 14.90 Å contains eight molecules. PATTERSON and FOURIER maps followed by least-squares refinement yielded atomic parameters, the R-value being 11.7%. Each Ni atom is in the centre of a distorted tetrahedron built by 2 carbonyl groups and the bidentate ligand, which forms a five-membered ring (almost planar) with the central atom.     

Die Kristallstruktur der monoklinen Form von As2O3 (Claudetit II)

Claudetite II crystallizes monoclinic (a ₀=7.99,b ₀=4.65,c ₀=9.12 Å, β=78.3°;Z=4) with space group P2₁/n-C _2h ⁵ . AnR-factor of 0.07 was obtained from 568 observed independent reflections using individual anisotropic temperature factors. Each of the two crystallographically different As-atoms forms a flat trigonal pyramid with three oxygens. The pyramids are connected in two dimensions by common corners to form undulating sheets parallel to (001).     

Kristallstruktur von Cu10Sn3(m)

Zusammenfassung Cu₁₀Sn₃(m) hat eine hexagonale Struktur, die in enger Verwandtschaft zur Struktur des CuZn steht. Einer der Hauptunterschiede beider Strukturen ist eine Stapelvariation der Schichten parallel (111)_CuZn. Aus dieser folgen weitere Verschiebungen der Atome, so daß die Struktur auch als Variante der NiAs-Struktur beschrieben werden kann. Gründe für die Stapelvariation lassen sich aus Annahmen über die Ortskorrelation der Elektronen herleiten.

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Crystal structure of Cu₁₀Sn₃(m)

Cu₁₀Sn₃(m) has a hexagonal structure, which is closely related to the structure of Cuzn. One of the main differences of these structures is a stacking variation of the layers parallel (111)_CuZn, which implies further shifts of atoms so that the structure may also be described as a variant of the NiAs structure. Causes for the stacking variation may be derived from assumptions on the spatial correlation of the electrons.

     

Die Kristallstruktur von BaTeO3

Crystal Structure of BaTeO₃ Crystals of BaTeO₃ were prepared from melts. BaTeO₃ is isotropic with KClO₃ and crystallizes in the monoclinic system, space group P2₁/m. The lattice parameters are a = 4.63₃, b = 5.95₂, c = 7.30₈ Å, β = 111.2°. The formula unit is 2. The crystal structure was determined by Patterson synthesis, refined by least squares and confirmed by (F_o — F_c) synthesis. Using isotropic temperature corrections the R-value of 1072 observed reflections calculated as 0.748, and anisotropic the R-value as 0.702. In BaTeO₃ tellurium forms with three oxygen atoms pyramidal TeO₃-groups, barium has to oxygen atoms the coordination 7+2. The TeO₃ groups are not linked one with another, but with the BaO₉ polyhedrons by common corners and edges, the latter are linked one with another only by common edges.     

Die Kristallstruktur von Kalium-trithiowolframat-chlorid K3(WOS3)Cl

A recently prepared new thiotungstate has been characterized by three-dimensional X-ray structure analysis, to be a double salt, containing K₂WOS₃ and KCl in equimolar proportions: potassium trithiotungstate chloride, K₃(WOS₃)Cl. Space group: Pca2₁ with a = 12.507, b = 6.317, c = 12,371 Å, Z = 4. The compound represents a new structure type with stoichiometry M^I₂XY₄ · M^IZ. Besides isolated tetrahedral WOS₃^2- ions (bond lengths W–O 1.760 Å, W–S 2.208, 2.197, 2.196 Å) the structure contains Cl^? ions octahedrally co-ordinated by K⁺, the K⁺ ions having 5S + 10 + 2Cl as neighbours. The dimensions of the WOS₃^2? ions in this compound show that, as in other transition metal oxo-, thio- and selenoanions, strong π bonding is present, the W–S bonds taking part in the π bond system.     

Die Kristallstruktur von Ag3Co(CN)6

The crystal structure of the hexagonal Ag₃Co(CN)₆ (a = 7.03 Å, c = 7.13 Å, Z = 1) has been determined by X-ray powder methods. The structure factor calculations based on the space group D lead to a reliability index R of 0.062, the R̃-value from F²-sums of systematically coinciding reflections being 0.064. The cobalt atoms are located in the position 1 a (0,0,0), the silver atoms in 3g (1/2,0,1/2;0,1/2,1/2;1/2,1/2,1/2). The carbon and nitrogen atoms occupy the position 6k. The interatomic distance are: Co-C = 1.89 Å, C-N = 1.14 Å, Ag-N = 2.06 Å. The angle C-N-Ag is 157.3º.     

Die Kristallstruktur von In(CH2Ph)3

Crystal Structure of In(CH₂Ph)₃ The reaction of InCl₃ with PhCH₂MgCl forms tribenzylindane 1 , precipitating from toluene as pale yellow crystals. The crystal structure shows one dimensional chains of 1 in a zigzag arrangement. The synthesis and characterization of (PhCH₂)₂InCl 2 and PhCH₂InCl₂ 3 is reported.     

Die Kristallstruktur von H3Co(CN)6

The crystal structure of the hexagonal H₃Co(CN)₆ (a = 6.43 Å, c = 5.70 Å, Z = 1) has been determined by X-ray powder methods. The space group is D (at least pseudo), the cobalt atoms being in (0, 0, 0). Structure factor calculations lead to a final R-value of 13.2%, based on F²-sums of coinciding reflections. The carbon and nitrogen atoms are located at the vertices of a slightly distorted octahedron around the cobalt atom; the angle Co? C? N is 177°. The interatomic distances are: Co? C = 1.89 Å, Co? N = 2,98 Å, C? N = 1.09 Å. The pseudo-octahedral units of Co(CN)₆ are linked together by N? H? N bridges. Infrared spectra show that the most probable linkage is the one with a N? H? N-bond length of 2.7 Å.     

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.

     

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 von Cr3GeN

The crystal structure of Cr₃GeN has been determined by single crystal methods: $$\begin{gathered} Space group P \bar 42_1 m - D_{2d}^3 ; \hfill \\ a = 5.375{\AA}; c = 4.012 {\AA}; c/a = 0.7465 \hfill \\ \end{gathered} $$ The close relationship of Cr₃GeN with the phases having filled U₃Si-type and the perowskite carbides and-nitrides will be discussed.     

Die Kristallstruktur von Aza-closo-decaboran NB9H10

The Crystal Structure of Aza-closo-decaborane, NB₉H₁₀ Aza-closo-decaborane(10), NB₉H₁₀, crystallizes in the space group P2₁/n. The NB₉ skeleton forms a distorted bicapped tetragonal antiprism with the N atom in a capping position. The structural data are compared to those of aza-closo-dodecaborane(12), NB₁₁H₁₂.     

Die Kristallstruktur von Bi2O2Se

Bi₂O₂Se crystallizes in the (Na_0.25Bi_0.75)₂O₂Cl type structure (space group I4mmm–D _4h ¹⁷ ;a=3.891 Å,c=12.21₃ Å). The crystal chemical properties of the bismuth oxiselenide are discussed in connection with the other compounds having this structure type.

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Herrn Prof. Dr.F. Hecht zum 70. Geburtstag gewidmet.     

Die Kristallstruktur von α-CaCr2O4

The Crystal Structure of α-CaCr₂O₄ Single crystals of the high temperature modifikation α-CaCr₂O₄ were investigated by X-Ray goniometer data. (a = 11.059, b = 5.836, c = 5.114 Å, space group D–Pmmn). α-CaCr₂O₄ is isotypic with SrCr₂O₄.