Ein Beitrag zur Verbindung ScOOH

Zusammenfassung Aus Scandiummetall und Kohlepulver hergestelltes ScC zersetzt sich bei Lagern an Luft unter Bildung von -ScOOH. Dagegen bleibt ScC, das durch Carburieren aus Sc₂O₃ erhalten wurde, unter denselben Bedingungen selbst nach mehreren Monaten unverändert. Das gebildete -ScOOH ist sehr gut kristallisiert, viel besser als durch Fällung gewonnene Präparate. Die vonMilligan undMcAtee ermittelte Böhmit-Struktur wird bestätigt; die Gitterkonstanten wurden neu bestimmt.     

Metastabile Oxometallate der Lanthanoidmetalle:.Zur Kenntnis von Sr3Pr4O9 und Sr3La2Sm2O9 mit einem Beitrag über SrPr2O4

Metastable Compounds of Rare Earth Oxides. About Sr₃Pr₄O₉ and Sr₃La₂Sm₂O₉ with a Remark about SrPr₂O₄ Sr₃Pr₄O₉ (A) and Sr₃La₂Sm₂O₉ (B) are for the first time prepared and investigated by X-ray single crystal work. Both compounds crystallize with monoclinic symmetry (space group C_s⁴? Cc, Z = 4) with (A) a = 11.468; b = 7.262; c = 13.218 Å; β = 115.61°, (B) a = 11.518; b = 7.263; c = 13.290 Å; β = 115.61°. (A) and (B) are metastable with high disorder in the metal positions. All of the metal positions are occupied with a statistical distribution of Sr²⁺ and Ln³⁺. (A) decomposes in the hitherto unknown compound SrPr₂O₄. It belongs to the calciumferrite type compounds.     

Ein Beitrag über Sr2RuO4 und Sr3Ru2O7 Zur Oktaederstreckung von M4+ in K2NiF4- und Sr3Ti2O7-Typ-Verbindungen

On the Thermal Decomposition of Hg₂I₂ and the Hg? I State Diagram Solid Hg₂I₂ decomposes congruently in Hg and HgI₂. The entropy S°(Hg₂I₂,s,298) = (55,5 ± 1) cal/K · mol and the enthalpy of formation ΔH_f°(Hg₂I₂, s, 298) = (?30,0 ± 2) kcal/mol are derived from the decomposition equilibrium. The phase diagram of the whole system Hg? I was constructed from investigations by DTA and total pressure measurements in the partial systems Hg? Hg₂I₂, Hg₂I₂? HgI₂, and HgI₂? I₂. It follows, that Hg₂I₂ melts incongruently at 297°C and decomposes in a Hg-rich and HgI₂-rich melt. The emerging miscibility gap is assumed to close at a temperature near 500°C.     

Zur Kenntnis eines gemischtvalenten Oxochromats(III,IV): Sr4Cr3O9

About a Mixed-Valence-Oxochromate(III, IV): Sr₄Cr₃O₉ Single crystals of the hitherto unknown compound Sr₄Cr₃O₉ were prepared and examined by four circle diffractometer technique (space group C–P3, a = 9.6182; c = 7.8736 Å, Z = 3). The point positions of chromium are occupied statistically by Cr³⁺ and Cr⁴⁺. The Cr³⁺/Cr⁴⁺-coordination is partly unusual, there are one dimensional chains of CrO₆-polyhedra incorporated in a [Sr₄O₉]^10?-network.     

Die Kristallstruktur der Verbindung LiNa[Ge4O9]

Zusammenfassung Die Kristallstruktur der Verbindung LiNa[Ge₄O₉] wird durch dreidimensionale Patterson- und Fourier-Synthesen bestimmt und mit Hilfe der Methode der kleinsten Quadrate verfeinert. Die rhombische Elementarzelle (Pcca-D _2h ⁸ ) mit den Abmessungen:a=9,31,b=4,68,c=15,88 Å enthält 4 Formeleinheiten. Die Struktur wird aus [GeO₃] _n -Ketten mit tetraedrisch koordiniertem Germanium aufgebaut, die über [GeO₆]-Oktaeder zu einem dreidimensionalen Gerüst vernetzt sind. Als mittlere interatomare Ge-O-Abstände wurden erhalten: 1,758 [4] und 1,866[6] Å. Die Verbindung LiNa[Ge₄O₉] stellt ein Endglied der Mischreihe Li_2–x Na _x [Ge₄O₉] dar.

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Crystal structure of LiNa[Ge₄O₉]

The crystal structure of LiNa[Ge₄O₉] has been determined by means of three-dimensional Patterson and electron density syntheses and refined by least-squares methods. The orthorhombic unit cell (Pcca-D _2h ⁸ ) having the lattice parametersa=9.31,b=4.68 andc=15.88 Å contains 4 formula units. The crystal structure consists of [GeO₃] _n -chains of tetrahedrally coordinated Ge-atoms which are connected by [GeO₆]-octahedra to form a three-dimensional framework. The interatomic Ge-O-distances are found to be 1.758[4] and 1.866[6] Å. The compound LiNa[Ge₄O₉] represents a member of the solid solution series Li_2–x Na _x [Ge₄O₉].

     

Über die Verbindung Sr7Mn4O15 und Beziehungen zur Struktur von Sr2MnO4 und α-SrMnO3

On the Compound Sr₇Mn₄O₁₅ and Structure Relations to Sr₂MnO₄ and α-SrMnO₃ The “compound” hitherto described as a α modification of Sr₂MnO₄ is shown to consist of a mixture of SrO and the new monoclinic compound Sr₇Mn₄O₁₅ crystallizing in the space group P 2₁/c, a = 681.78(6), b = 962.24(8), c = 1038.0(1) pm, β = 91.886(7)°, Z = 2. Up to 0.3 mm long black crystals were grown from prereacted Sr₇Mn₄O₁₅, SrO, and SrCl₂ at 1350°C in a sealed platinum tube under argon. Its structure is related to α-SrMnO₃. It contains layers of cornershared double octahedra [O_2/2OMnO₃MnO₂O_1/2]^7? parallel to (100). Above 100 K the magnetism of Sr₇Mn₄O₁₅ follows the Curie Weiss law with Θ ～ -426 K and a moment μ_eff = 3.62 μ_B corresponding Mn⁴⁺.     

Perovskite related phases in the Sr5Nb4O15 - SrTiO3 - Sr4Nb2O9 system

Phase relations have been investigated within the Sr₅Nb₄O₁₅−SrTiO₃−Sr₄Nb₂O₉ region of the SrO−Nb₂O₅−TiO₂ system with a view to clarifying the occurrence of fully oxidised perovskite related phases. Overall phase analysis was carried out by powder X-ray diffraction and microstructures were clarified by transmission electron microscopy. There is only one main composition triangle in this area at 1350°C. The tie-line between Sr₅Nb₄O₁₅ and SrTiO₃ contains a homologous series of hexagonal layered perovskite phases including Sr₆Nb₄TiO₁₈ and Sr₇Nb₄Ti₂O₂₁. The phase Sr₄Nb₂O₉ is a nonstoichiometric phase with a disordered perovskite structure. There is some extension of this phase along the Sr₄Nb₂O₉−SrTiO₃ tie-line, but SrTiO₃ does not show a significant composition range. Samples with a composition Sr₄Nb₂O₉, when heated at 900°C show several ordered modifications. Samples along the Sr₄Nb₂O₉−SrTiO₃ tie-line which are annealed at 900°C contain these ordered materials together with samples showing considerable short range order which increases as the Ti content increases.     

Zur Kenntnis von Sr2Bi3V3O14

On Sr₂Bi₃V₃O₁₄ Single crystals of the hitherto unknown compound Sr₃Bi₃V₃O₁₄ were prepared and investigated by X-ray work. It crystallizes with triclinic symmetry, space group P1 , a = 7.0838, b = 7.1732, c = 14.1067 Å; α = 97.46, β = 98.70, γ = 110.99°, Z = 2. The crystal structure is characterized by VO₄ tetrahedra and one side open Bi³⁺ coordination inside Bi₂O₁₁ groups.     

Zur Kenntnis von Zn4Ta2O9

About the New Compound Zn₄Ta₂O₉ The hitherto unknown compound Zn₄Ta₂O₉was prepared by high temperature reaction (CO₂-LASER technique). The X-ray investigation of single crystal shows monoclinic symmetry (space group C? C2/c) with a = 15.002(6), b = 8.954(1), c = 10.345(4)Å and β = 93.64(3)°. Zn₄Ta₂O₉ consists of a Zn/O-network with incorporated one-dimensional TaO₆-chains. The edge connected TaO₆-octahedrals are occupied by Ta⁵⁺ and 0.5 Zn²⁺ respectively. The crystal chemistry of this compound in respect to other Zn-oxotantalates are discussed.     

Ein neues Oxohalogenoferrat: Sr3Fe2O5Cl2

About a New Oxohalogenoferrite: Sr₃Fe₂O₅Cl₂ The preparation and single crystal X-ray investigation of Sr₃Fe₂O₅Cl₂ are described. This compound belongs to the Sr₃Ti₂O₇ structure with a = 3.942(2) and c = 23.786(12) Å; space group D?I4/mmm. Sr₃Fe₂O₅Cl₂ shows an one-sided streched FeO₅Cl octahedron in respect to the Fe? Cl distances. This particularity is discussed in comparison to other K₂NiF₄-type compounds.     

Zur Kristallstruktur von Ni4Nb2O9

Crystal Structure of Ni₄Nb₂O₉ Single crystals of Ni₄Nb₂O₉ were prepared and examined by X-ray work (space group C–Fd2d; a = 10.101(13), b = 17.5126(51), c = 28.6364(87) Å; Z = 32). Ni₄Nb₂O₉ has 480 atoms per unit cell, thus forming a complicated threedimensional NiO₆-octahedra framework. NbO₆-double octahedra are deposited in this framework. The relations to other A₄B₂O₉ compounds are discussed.     

Ein Beitrag zur Kristallchemie von BaBiO3

A Contribution on the Crystal Chemistry of BaBiO₃ Single crystals of BaBiO₃ were prepared and investigated by X-Ray methods (a = 436.4, c = 451.8 pm, space group D–P4 2m). It was found a statistical distribution of Ba²⁺ and O^2?, which leads to different distances in the Bi? O surrounding. A discussion of two possible polyhedral configurations in respect to the valence of Bi is given.     

Ein neues metastabiles Zinkoxovanadat: Zn4V2O9

For the first time Zn₄V₂O₉ was prepared and investigated by single crystal X-ray methods. The metastable compound exists between a CO₂-Laser generated flux and the solid ZnO/V₂O₅ material. The quenched light brown crystals show a monoclinic symmetry (space group C ₂ ² —P2₁,a=10.488 (5),b=8.198 (6),c=9.682 (5) Å; =118.66 (4)°;Z=4]. Zn₄V₂O₉ has a characteristic Zn/O-framework with incorporated V⁵⁺ in tetrahedral coordination. The relationship to Zn₄Ta₂O₉ and the calculation of the madelung part of lattice energy (MAPLE) in respect to the metastable character are discussed.

     

在NiCo2O4电极和Nd0.8Sr0.2CoO3电极上氧析出反应的研究

本文用稳态法测定了塔费尔斜率、OH^-离子的表观反应级数和表观活化能,着重分析了线性电位扫描图及该反应的暂态特性。提出了在该电极上氧气析出反应的初步机理。     

Zur Verbindungsbildung von MeO: M2O3. VIII. Synthese und Aufbau der metastabilen Verbindung CaEr3O5,5

Compound Formation of MeO: M₂O₃. VIII. Preparation and Structure of the Metastable Compound CaEr₃O_5,5 Single crystal of CaEr₃O_5,5 were prepared at high temperatures by CO₂-Laser-technique. X-ray structure determination leads to a monoclinic symmetry (Space group C—C2/m; a = 6.524, b = 3.546, c = 11.754 Å, β = 92.32°). There are significant differences between CaEr₃O_5.5 and CaTm₃O_5.5.     

Nd4Ti9O24: Präparation und Struktur

Preparation and Crystal Structure of Nd₄Ti₉O₂₄ The compound Nd₄Ti₉O₂₄ was prepared by heating mixtures of Nd₂O₃/TiO₂ (1 : 4.5) at temperatures of T = 1 330°C in air (2× 1d). Single crystals of Nd₄Ti₉O₂₄ were obtained by chemical transport reaction (T₂→T₁; T₁ = 1000°C, T₁ = 900°C, 14 d) using chlorine (p(Cl₂, 298 K) = 1 atm) as transport agent with Nd₄Ti₉O₂₄ as starting material. Nd₄Ti₉O₂₄ crystallizes in the orthorhombic space group Fddd (No. 70) with a = 13.9926(11) Å, b = 35.2844(21) Å, c = 14.4676(17) Å (Z = 16). The structure was refined to give R = 4.0% and R, = 3.7%. Main building units are TiO₆ octahedra, NdO₆ distorted square antiprisms and NdO₆ octahedra.     

Zur Kenntnis der Verbindung H3P–BJ3

Phosphine or phosphonium iodide react with boron triiodide in CS₂ or benzene to form the adduct H₃P–BI₃. The water-sensitive white solid is thermally stable up to ～150°C. Its IR and NMR spectrum are recorded.     

ChemInform Abstract: Preliminary Crystal Structure of Mixed-Valency Sr4Ni3O9, the Actual Formula of the so-called Sr5Ni4O11.

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