Die Kristallstruktur von Diäthylamino-titantrichlorid

Diethylaminotitanium trichloride, (C₂H₅)₂NTiCl₃, is monoclinic with space group P2₁/n and a = 6.131 Å; b = 12.290 Å; c = 12.081 Å and β = 87.20°. There are four formula units per unit cell. The structure analysis with three-dimensional diffractometer data yielded an R-factor of 0.079 for 1509 observed reflexions. The titanium atom has coordination number six. The NTiCl₅ octahedra are linked into infinite zig-zag chains by sharing Cl? Cl edges. The nitrogen atom and one chlorine atom do not participate in bridging. The Ti? N distance at 1.852 Å is significantly shorter than a hypothetical pure single bond.     

Die Kristallstruktur von Li4SiO4

Zusammenfassung Die Kristallstruktur des Lithiumorthosilicats wurde mittels dreidimensionaler Fourier-Synthesen und nach der Methode der kleinsten Quadrate bestimmt. Die Gitterparameter der monoklinen Elementarzelle (C _2h ² –P2₁/m) betragen:a=5,14;b=6,10;c=5,30 Å und =90,5°. Die Struktur enthält isolierte [SiO₄]-Tetraeder, welche durch [LiO _n ]-Polyeder (n=4, 5, 6) verknüpft sind. Hervorzuheben ist, daß sämtliche Lithiumlagen nur partiell besetzt sind. Als mittlerer Si–O-Abstand wurde 1,632 Å erhalten; als Mittelwerte der Li–O-Abstände für die verschiedenen Koordinationszahlen ergeben sich: 1,975 [4]; 2,099 [5] und 2,247 [6] Å.

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The crystal structure of lithium orthosilicate has been determined by means of three-dimensional Fourier syntheses and the least squares method. The lattice parameters of the monoclinic unit cell (P2₁/m–C _2h ² ) are:a=5.14;b=6.10;c=5.30 Å and =90.5°. The crystal structure contains isolated [SiO₄]-tetrahedra being connected by [LiO _n ]-polyhedra (n=4, 5, 6). The positions of the lithium atoms are partially occupied only. The average interatomic Si–O distance is found to be 1.632 Å. The averaged values for Li–O distances given for the different coordination numbers are: 1.975 [4]; 2.099 [5] and 2.247 [6] Å.

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Mit 4 Abbildungen     

Die Kristallstruktur von Lithiummetaperiodat,LiIO4

The Crystal Structure of Lithiummetaperiodate, LiIO₄ For the first time single crystals of LiIO₄ were obtained. According to the results of an X-ray structure determination (monoclinic, P2₁/n; a = 525.5(3), b = 851.1(4), c = 796.9(5) pm, β = 104.21(3)°; Z = 4; 2 148 diffractometer data, R = 0.024) the coordination by oxygen is tetrahedral for iodine and strongly distorted trigonal bipyramidal for lithium. Two lithium-oxygen-polyhedra are connected via a common edge. LiIO₄ crystallises isostructural to LiAlH₄. The structure is discussed and compared to those of other metaperiodates and tetrahydridoaluminates.     

Die Kristallstruktur von Molybdännitridchlorid,MoNCI3

MoNCl₃ crystallises in the triclinic space group PI with 4 formula units per unit cell, the lattice constants being a = 9.14, b = 7.67, c = 8.15 Å; α = 108.8°, β = 99.3° and γ = 108.6°. The crystal structure was solved by means of three-dimensional PATTERSON and FOURIER syntheses and refined by the method of least squares to a reliability index of 5.8%. The structure is built up from two slightly different kinds of MoNCl₃ molecules having Mo? N triple bonds (Mo? N distances 1.64 and 1.67 Å). Each N atom is coordinated to the Mo atom of a neighbouring molecule in such a way that tetramers with the pseudosymmetry 4/m are formed. The tetramers are linked together by bridging Cl atoms so that puckered layers parallel to (010) result.     

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 Ir4Ge5

Zusammenfassung Mittels Fourier- und Differenz-Fourier-Synthesen wird eine Struktur für Ir₄Ge₅ errechnet. Der Aufbau, der einem Abkömmling des TiSi₂-Typs mit starkem Unterschuß desB-Elements entspricht, ist durch Stapelung in Richtung derc-Achse gemäßn=4 charakterisiert.

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By means of Fourier- and difference Fourier-synthesis a crystal structure for Ir₄Ge₅ was calculated. The crystal structure of Ir₄Ge₅, a derivative of the TiSi₂-type structure with a strong deficiency of theB-element, is characterized by a 4-fold stacking of the subcell in thec-direction.

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Herrn Professor Dr.J. W. Breitenbach zum 60. Geburtstag gewidmet.     

Die Kristallstruktur von Nb5Cu4Si4

Zusammenfassung Die Struktur von Nb₅Cu₄Si₄ wird mit Hilfe von Einkristallmethoden bestimmt und verfeinert. Die Abmessungen der tetragonalen, innenzentrierten Elementarzelle sind:a=10,1908 undc=3,6004 Å. Die Zelle beinhaltet 2 Formeleinheiten, die Raumgruppe ist C _4h ⁵ –I4/m.

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The crystal structure of Nb₅Cu₄Si₄ has been determined and refined by single-crystal X-ray methods. The cell dimensions of the tetragonal body-centered unit cell are found to be:a=10,1908 andc=3,6004Å. The cell content is 2 formula units, the space group is C _4h ⁵ –I4/m.

     

Die Reaktionen von Benzoylierungsmitteln mit Phosphoriger Säure

Reactions of Benzoylating Agents with Phosphorous Acid H₃PO₃ reacts with (C₆H₅CO)₂O to yield C₆H₅C(OH)(PO₃H₂)₂ 1 . In contrast, the reaction with C₆H₅COCl proceeds with the formation of C₆H₅CCl(PO₃H₂)₂ 2 and p-ClC₆H₄CH(PO₃H₂)₂ 3 . The best yields of 2 and 3 are obtained, if the reaction are carried out under pressure. 2 is rapidly hydrolysed in alkaline solution at elevated temperatures to 1 .     

Die Kristallstruktur von CsTcO4 [1]

The Crystal Structure of CsTcO₄ CsTcO₄ crystallizes orthorhombic with a = 5.72₇, b = 5.92₁ and c = 14.34 Å. Z = 4, space group Pnma (Nr. 62, I.T.). The metal positions were refined by single crystal data, the oxygen positions first determined: the CsTcO₄ structure is a slight distortion of the scheelite arrangement (parameters: see text). The MADELUNG Part of Lattice Energy, MAPLE, ?Mean Effective Ionic Radii”?, MEIR, and Effective Coordination Numbers, ECoN, are calculated and discussed.     

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 von Ammonium-dioxodifluorovanadat

The Crystal Structure of NH₄VO₂F₂ Crystals of NH₄VO₂F₂ are monoclinic, space group Pc, a = 4.814(2), b = 11.434(3), c = 7.214(2) Å, β = 108.84(4)°. Z = 4. The VO₂F-ion is polymeric. The structure consists of endless chains of strongly distorted octahedra with common edges. Two adjacent polyhedra are linked by an asymmetrical oxygen bridge (bond lengths 1.74 and 2.21 Å) and an asymmetrical fluorine bridge (bond lengths 1.97 und 2.21 Å). The terminal V? O- and V? F-distances are 1.55 and 1.86 Å, respectively.     

Die Kristallstruktur von Thalliumtrifluorid

The crystal structure of thallium trifluoride The crystal structure of TlF₃ has been determined form single crystal diffraction data. The unit cell is orthorhombic, space group Pnma≠D, with a = 5.825, b = 7.024, c = 4.851 Å, Z = 4. Each Tl has 8 nearest F-neighbours. The Tl–F distances range from 2.09 to 2.49 Å.     

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 BaHg(CN)4 · 4 Pyridin

Crystal Structure of BaHg(CN)₄ · 4 Pyridine The structure of the tetragonal BaHg(CN)₄ · 4 Pyridine (space group I4 , a = 1119.4(7), c = 1 057.9(7) pm, Z = 2, d_c = 1.87 g · cm^?3) contains tetrahedral Hg(CN)₄ and bisdisphenoide Ba(NC)₄(py)₄ groups, which are linked together by Hg? CN? Ba bridges. The BaHg(CN)₄ framework consists of a 3-dimensional network of all round edge-sharing tetrahedrons. The analogous strontium compound is isotype with a = 1 108.2(9) and c = 1 035.3(14) pm.     

Die Kristallstruktur von Zirkoniumtetrachlorid

Zirconium(IV) chloride crystallizes in the monoclinic space group P2/c with a = 6.361, b = 7.407, c = 6.256 Å β = 109.30°, Z = 2. The single crystal X-ray structure analysis shows the structure to consist of an arrangement of [ZrCl_4/2Cl₂] zig-zag chains. Within the chains each Zr atom has an octahedral environment; the octahedra are linked through sharing edges, the two terminal Cl ligands being mutually in cis-position. The structure is closely related to those of TcCl₄, PtI₄ and MoOCl₃. The Zr? Cl bond lengths are 2.655 (bridge), 2.498 (bridge) and 2.307 Å (terminal) ZrBr₄, HfCl₄, and HfBr₄ are isostructural with ZrCl₄