Eu3+ und Eu2+ in Oxometallaten der Zusammensetzung MBeLn2O5: SrBeEu2O5 und EuBeNd2O5

Eu³⁺ and Eu²⁺ in Oxides of the Composition MBeLn₂O₅: SrBeEu₂O₅ and EuBeNd₂O₅ Single crystals of (I): SrBeEu₂O₅ and (II): EuBeNd₂O₅ were prepared by CO₂-LASER (I) in air and plasma torch (II) technique in H₂ atmosphere. X-ray investigations led to orthorhombic symmetry, space group D-Pnma; (I): a = 9.488, b = 7.156, c = 6.495 Å; (II): a = 9.534, b = 7.225, c = 6.544 Å, Z = 4. Sr²⁺ and Eu³⁺ as well as Eu²⁺ and Nd³⁺ are in statistical distribution within a Kagomé framework. Both compounds are discussed with respect to the monoclinic form of MBeLn₂O₅.     

ChemInform Abstract: V2O2F4 (H2O)2·H2O: A New V4+ Layer Structure Related to VOF3.

Single crystals of the title compound are prepared by hydrothermal reaction of VF₃ and H₂SeO₃ in ethylene glycol/HF (40%) in the presence of Et₂NH (autoclave, 393 K, 4 d).     

Zur Kristallchemie der Blei-Lanthanoid-Oxoaluminate. Zur Kenntnis von Pb2HoAl3O8 und Pb2LuAl3O8

Crystal Chemistry of the Lead Lanthanide Oxoaluminates. On Pb₂HoAl₃O₈ and Pb₂LuAl₃O₈ . Single crystals of (I) Pb₂HoAl₃O₈ and (II) Pb₂LuAl₃O₈ were prepared by flux technique and investigated by X-ray methods. It crystallizes with cubic symmetry, space group O–P4₂/n 3 2/m, (I): a = 9.4164(13) Å, (II): a = 9.3486(8) Å, Z = 4. The new structure type shows AlO₄ tetrahedra, LnO₈ hexagonal bipyramids and one sided coordinated Pb²⁺ within heterocubane units. The crystal chemical relationships to other lead oxides containing heterocubane Pb₄O₄ units are discussed.     

Ein neues Kupfercobaltboratoxid mit isolierten B2O5-Baugruppen: Cu2Co(B2O5)O

On a New Copper Cobalt Borate Oxide with Isolated B₂O₅ Units: Cu₂Co(B₂O₅)O Single crystals of a new compound with the empirical formula Cu₂CoB₂O₆ were obtained by using a B₂O₃ flux technique. X-ray single crystal technique led to a new structure type. Cu₂CoB₂O₆ crystallizes monoclinic, space group C-P2₁/c (No. 14); a = 3.2250(6); b = 14.847(1); c = 9.1171(6) Å; β = 93.67°; Z = 4. All metal sites are octahedrally coordinated and form a two dimensional framework consisting of edge sharing octahedra ribbons. In addition one observes isolated B₂O₅-units and oxygen which is not coordinated to boron. The far relation to the crystal structure of the mineral Warwickite is illustrated.     

ChemInform Abstract: Synthesis,Structural Characterization and Optical Properties of a New Cesium Aluminum Borate,Cs2Al2B2O7.

The new title compound is prepared by solid state reaction of Cs₂CO₃, Al₂O₃, and H₃BO₃ (1000 °C).     

Ein Beitrag über CuPrMo2O8 und CuTbMo2O8

A Contribution on CuPrMo₂O₈ and CuTbMo₂O₈ Single crystals of (I): CuPrMo₂O₈ and (II): CuTbMo₂O₈ were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D-Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo₂O₈, showing isolated MoO₄ tetrahedra, square antiprismatic coordination of Ln³⁺ and Cu⁺ besides one edge of an O^2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu²⁺ in combination with mixed valences of Mo⁶⁺ and Mo⁵⁺ on the molybdenum point positions.     

ChemInform Abstract: Synthesis and Characterization of a Disordered Variant of KB5O7(OH)2.

The title compound is hydrothermally synthesized from a mixture of KNO₃, B₂O₃, and Ce(NO₃)₃·6H₂O with a molar ratio of 1:1:0.07 (autoclave, 513 K, 3 d).     

ChemInform Abstract: Density Functional Theory Calculations of UO2 Oxidation: Evolution of UO2‐x,U4O9‐y,U3O7, and U3O8.

DFT calculations of UO₂ oxidation indicate stable compounds U₄O_8.889, U₃O₇, and U₃O_7.333, which are based on ordering of split quad‐interstitial clusters.     

外偶极电场作用下H_2O,D_2O和T_2O的可逆分解电压

采用密度泛函B3P86方法和6-311++G(3df,3pf)基组,计算了在-0.05～0.05a.u.外偶极电场作用下,H2O,D2O,T2O,H2,D2,T2,O2的电子能量、核运动能量和熵值,在此基础上通过计算H2O(g)→H2(g)+O2(g)、D2O(g)→D2(g)+O2(g)、T2O(g)→T2(g)+O2(g)的焓变ΔH、熵变ΔS、Gibbs函数变化ΔG,最后得到了H2O,D2O,T2O的可逆分解电压Er.计算结果表明,外偶极电场存在时,H2O,D2O,T2O的Gibbs自由能变ΔG和可逆分解电压Er都有明显的变化,当外偶极电场正方向增加时,其Gibbs自由能变ΔG和可逆分解电压Er均趋于线性增加;当外偶极电场负方向增加时,其Gibbs自由能变ΔG和可逆分解电压Er均趋于线性减小;在相同外偶极电场作用下,Gibbs自由能变ΔG和可逆分解电压Er随H2O,D2O,T2O依次增加.     

ChemInform Abstract: Synthesis and Characterizations of Two Anhydrous Metal Borophosphates: M2IIIBP3O12 (M: Fe,In).

The title compounds are obtained quantitatively by reacting mixtures of M₂O₃ (M: Fe, In), H₃BO₃, and NH₄H₂PO₄ in a molar ratio of 1:1:3 at 1153 K.     

Über die quasi-binären Systeme NaNO2/Na2O und NaCN/Na2O. Phasendiagramme und Natrium-Ionenleitung in Na3O(NO2) und Na3O(CN)

On the Quasi-Binary Systems NaNO₂/Na₂O and NaCN/Na₂O. Phase Diagrams and Sodium Ion Conductivity of Na₃O(NO₂) and Na₃O(CN) Measurements of the electrical conductivities of Na₃O(NO₂) and Na₃O(CN) show sharp increases in conductivity at temperatures between 200° and 250°C, According to the phase diagrams of the quasi-binary systems NaNO₂/Na₂O and NaCN/Na₂O this is not an effect established by fusion. It seems to be a consequence of a “melting” of the sodium sublattice or the rotational disorder of complex anions.     

ChemInform Abstract: Tetrayttrium Difluoride Disilicate Orthosilicate,Y4F2[Si2O7][SiO4].

Colorless lath-shaped single crystals of the title compound are obtained from a melt of Y₂O₃, YF₃, and SiO₂ (2:5:3 molar ratio) using CsCl as a flux (evacuated silica tube, 973 K, 9 d, 10 K/h cooling rate).     

Ein neues Kupferzinnboratoxid mit isolierten BO3-Baugruppen: Cu5Sn(BO3)2O4

On a New Copper Tin Borate Oxide with Isolated BO₃ Units: Cu₅Sn(BO₃)₂O₄ Single Crystals of the new compound Cu₅Sn(BO₃)₂O₄ were obtained by a B₂O₃ fluxtechnique. They crystallize in a monoclinic distorted variant of a Ludwigite structure with a partly ordered metal distribution. X-ray investigations on single crystals led to the space group C–P2₁/c (No. 14); a = 6.3526(7); b = 9.502(1); c = 12.100(9) Å; β = 93.30(3)°; Z = 4. All metal-sites are distorted octahedraly coordinated by oxygen-ions. The structure contains BO₃-units and oxygen which is not coordinated to boron.     

Herstellung keramischer Pulver. IX. Zur Bildung von NiMn2 O4 und ZnMn2O4 durch Zersetzung von [Ni(H2O)6] (MnO4)2 und [Zn(H2O)6] (MnO4)2

Preparation of Ceramic Powders. IX. NiMn₂O₄ and ZnMn₂O₄ Formation by Decomposition of [Ni(H₂O)₆] (MnO₄)₂ and [Zn(H₂O)₆] (MnO₄)₂ Improved preparation of Ba(MnO₄)₂ from BaMnO₄ is reported. Thermal or hydrothermal decomposition of [Ni(H₂O)₆] (MnO₄)₂ yields intermediately an amorphous manganate(IV) which forms crystalline NiMnO₃ and α-Mn₂O₃ in the range T > 400°C. NiMn₂O₄ is formed above 730°C in accordance with the phase diagram. On the other hand, ZnMn₂O₄ is already at 300°C obtained from [Zn(H₂O)₆](MnO₄)₂ at hydrothermal conditions.     

Zur Verbindungsbildung von MeO: M2O3. IV. Zur Struktur von monoklinem SrAl2O4

Einkristalle von SrAl₂O₄ wurden durch Hochtemperaturreaktionen von SrO mit Al₂O₃ dargestellt und röntgenographisch untersucht (a = 844,7; b = 881,6; c = 516,3 pm;β = 93,4₂°; Raumgruppe C–;P2₁, Z = 4). Die Tetraederabfolge in den Sechsringen dieser aufgefüllten Tridymit-Struktur wird mit der ähnlicher Oxometallate verglichen. Compound Formation MeO:M₂O₃. IV. Structure of Monoclinic SrAl₂O₄ Single crystals of SrAl₂O₄ were prepared by high temperature CO₂-LASER technique and investigated by X-ray methods. (a = 844.7; b = 881.6; c = 516.3 pm; β = 93.4₂°; space group C–P2₁, Z = 4). The orientation of the tetrahedra in this stuffed tridymite structure is discussed in comparison with related oxometallates.     

Oxydationsprodukte intermetallischer Phasen. III. Tieftemperaturformen von K2Sn2O3 und Rb2Sn2O3 und eine Notiz über K2Ge2O3

Oxidation Products of Intermetallic Compounds. III. Low Temperature Forms of K₂Sn₂O₃ and Rb₂Sn₂O₃ and a Notice about K₂Ge₂O₃ By controlled oxidation of KSn (at 320°C) and RbSn (at 410°C) with O₂ the hitherto unknown low temperature forms of K₂Sn₂O₃ (a = 8.4100(8) Å) and Rb₂Sn₂O₃ (a = 8.6368(8) Å) are obtained, which are isotopic with cubic K₂Pb₂O₃. Oxidation at higher temperatures (at 510–5207°C) leads to the well-known HT-forms. The Madelung Part of Lattic Energie, MAPLE, is calculated for both compounds. K₂Pb₂O₃, Rb₂Pb₂O₃, Cs₂Pb₂O₃, and Cs₂Sn₂O₃ have been prepared too by oxidation of KPb, RbPb, CsPb, and CsSn. Oxidation of KGe (at 400°C) leads to the first oxogermanate(II), K₂Ge₂O₃ (cubic a = 8.339(1) Å, isotypic with K₂Pb₂O₃) together with K₆Ge₂O₇.     

Zur Verbindungsbildung von MeO: M2O3. Ein neuer Bautyp: SrCa2Sc6O12

The Reaction of MeO:M₂O₃. A New Structure Type: SrCa₂Sc₆O₁₂ The compound Sr_0.33Ca_0.67Sc₂O₄ shows a hitherto unknown hexagonal crystal structure (a = 9.659, c = 3.136 Å; Space group C?P6₃/m). A detailed discussion of the coordination polyhedrals and the similarity to CaSc₂O₄ are given.     

Über eine neu entdeckte Dimorphie an BaCoEr2O5

On a New Observed Dimorphism of BaCoEr₂O₅ Single crystals of BaCoEr₂O₅ were prepared by CO₂-LASER technique under N₂-atmosphere and investigated by X-ray single crystal methods. It crystallizes with orthorhombic symmetry, space group D-Pnma (a = 12.2787, b = 5.6826, c = 7.0344 Å; Z = 4). The so far unknown crystal structure of BaCoEr₂O₅ belongs to the BaCuLn₂O₅ type forming the dimorphic substance to the previously described Ni type of BaCoEr₂O₅.     

ChemInform Abstract: The Synthesis and Characterization of LaCa2Fe2GaO8.

The title compound is prepared from stoichiometric mixtures of La₂O₃, SrCO₃, Ga₂O₃, and Fe₂O₃ (flowing Ar, 1300 °C, 80 h) and characterized by neutron powder diffraction and magnetic measurements.     

Kaliumheptachlorodioxodimolybdat(V), KMo2O2Cl7

Potassium Heptachlorodioxodimolybdate(V), KMo₂O₂Cl₇ KMo₂O₂Cl₇ was obtained at 400 °C from the reaction of SCl₂ with molybdenum which contained traces of potassium. Its crystal structure is monoclinic, space group C2/c, a = 1094.1, b = 1139.1, c = 1018.0 pm, β = 110.16°, Z = 4. In the Mo₂O₂Cl₇^– ion two coordination octahedra share a common face with three chlorine atoms. The crystal structure can be derived from the CsNiCl₃ type by vacating one third of the Ni and two thirds of the Cs positions. The crystallographic group-subgroup relationship is given.