Der Chemische Transport von Re,ReO2 ReO3 und ReS2

The Chemical Transport of Re, ReO₃, ReO₃, and ReS₂ Chemical transport of Re, ReO₂, ReO_y and ReS, in the presence of J₂, of H₂O, and of both, J₂ + H₂O has been investigated experimentally. Experiments concerning the systems Re/J₂ and ReS₂/J₂ showed the importance of water traces, which could be diminished by reaction with graphite. The composition of the gas phases of the multicomponent systems involved have been calculated thermodynamieally. On this basis a discussion of the transport properties has been made. The important Re-containing moleculs are ReO₃J and ReO₃(OH). Gaseous rhenium iodides are insignificant. Favourable transport properties are found in the systems Re/H₂O Re/H₂O, J₂ ReO₂/H₂O, J₂ ReO₃/Re₂O₇, J₂ ReO₃/J₂ ReS₃/H₂O ReS₂/H₃O, J₂     

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.     

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.     

Über Perrhenate. 2. Zur Kenntnis von Li5ReO6 und Na5ReO6 – mit einer Bemerkung über Na5IO6

On Perrhenates. 2. On Li₅ReO₆ and Na₅ReO₆ — with a Note on Na₅IO₆ The crystal structures of Li₅ReO₆ and Na₅ReO₆ were determined for the first time in full detail from four-circle diffractometer data (AgKα radiation). They and Na₅IO₆, also (according to powder data) crystallize with the monoclinic system (C2/m, Z = 2). The structure may be described as a distorted derivative of the NaCl type; data see ?Inhaltsübersicht”?. Effective Coordination Numbers, ECoN, and the Madelung Parts of the Lattice Energy, MAPLE, have been calculated and are discussed.     

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.     

Über die Alkaliselenoarsenate(III) KAsSe3 · H2O,RbAsSe3 · 1/2 H2O und CsAsSe3 · 1/2 H2O

On the Alkali Selenoarsenates(III) KAsSe₃ · H₂O, RbAsSe₃ · 1/2 H₂O, and CsAsSe₃ · 1/2 H₂O The alkali selenoarsenates(III) KAsSe₃ · H₂O, RbAsSe₃ · 1/2 H₂O, and CsAsSe₃ · 1/2 H₂O have been prepared by hydrothermal reaction of the respective alkali carbonate with As₂Se₃ at a temperature of 135°C. Their X-ray structural analyses demonstrated that the compounds contain polyselenoarsenate(III) anions (AsSe₃^?)_n, in wich the basic units are ψ-AsSe₃ tetrahedra, which are linked together through Se? Se bonds into infinite zweier single chains. The Rb and Cs salts are isotypic.     

Massenspektrometrische Untersuchungen der Gasphase über CrCl3 und CrCl3/Cl2

Mass Spectrometric Investigations of the Vapor Phase over CrCl₃ and CrCl₃/Cl₂ The vapor in the system CrCl₃/Cl₂ is investigated by Knudsen-cell mass spectrometry in the temperature range between 770 and 910 K. The gaseous molecules CrCl_{3, g} and CrCl_{4, g} are identified mass spectrometrically; the molar heats of formation are determined by 2nd law calculations. CrCl_{3, g}: Δ_fH(298) = ?79.2 kcal; CrCl_4,g: Δ_fH(298) = ?103.2 kcal; the composition of the vapor in equilibrium with condensed CrCl_3,s, CrCl_2,s is calculated (Temperature 773–1273 K).     

Zwei neue Rubidiumlithiumzincate: RbLiZnO2 und RbLiZn2O3 (mit einer Bemerkung über CsLiZnO2)

New Rubidium Lithium Zincates: RbLiZnO₂ and RbLiZn₂O₃ For the first time colourless single crystals of RbLiZnO₂ (A) and RbLiZn₂O₃ (B) have been prepared. Both crystallize tetragonally, A: space group I4/mmm, Z = 2, a = 351.84(4), c = 1153.3(2) pm; B: space group P4₂/mnm, Z = 4, a = 1 033.8(1), c = 342.8(1) pm. The crystal structures have been determined from four circle diffractometer data (MoKα; A: 155 hkl, R = 7.9%, R_w = 7.6%; B: 384 hkl, R = 7.0%, R_w = 4.6%). RbLiZnO₂ has the BaZn₂P₂ type of structure while RbLiZn₂O₃ exhibits a new structure type with linear chains of face shared cubes [O_4/2RbO_4/2RbO_4/2] as characteristic feature. For both oxides the Madelung part of lattice energy (MAPLE), and effective coordination numbers (ECoN) are calculated.     

Synthese und Kristallstrukturen von Chlororhenaten(III) mit den zweiwertigen Kationen Ethylendiammonium und Piperazinium:(EnH2)2(Pipzh2)[Re3Cl12]2· 6H2O,und (PipzH2) [Re3Cl12]CI·H2O und (Pipzh2) [Re3Cl11(H2O)]·3H2O

Synthesis and Crystal Structures of Chlororhenates(III) with the Divalent Cations Ethylenediammonium and Piperazinium: (EnH₂)₂(PipzH₂) [Re₃Cl₁₂]₂·6H₂O, (EnH₂) (PipzH₂) [Re₃Cl₁₂]Cl· H₂O, and (PipzH₂) [Re₃Cl₁₁(H₂O)] · 3H₂O The deep red salt (EnH₂)₂(PipzH₂)[Re₃CI₁₂] · 6 H₂O ( 1 ), (EnH₂)(PipzH₂)[Re₃Cl₁₂]CI · H₂O ( 2 ), and (PipzH₂)[Re₃Cl₁₁(H₂O)] · 3H₂O ( 3 ) crystallize upon evaporation from hydrochloride acid solutions of ReCl₃ on addition of ethylenediammonium chloride (EnH₂Cl₂) and/or piperazinium chloride (PipzH₂Cl₂). The crystal structures have been determined from four-circle diffractometer data. 1: monoclinic; a = 1889.63(11), b = 1615.82(8), c = 790.28(4)pm; β = 101.354(5)°; Z = 2; P2₁/n; R = 0.119, R_w = 0.070. 2: triclinic; a = 1330.35(4), b = 1051.14(5), c = 1165.32(6)pm; α = 122.308(4), β = 102.412(3), γ = 92.226(4)°; Z = 2, P1 ; R = 0.092, R_w = 0.059. 3: orthorhombic; a = 971.43(4), b = 1619.51(7), c = 1478.87(6)pm; Z = 4; Pbcm; R = 0.034, R_w = 0.032.     

Neues über Protein-Thiolgruppen und Disulfidbindungen

Eine der vom französischen Centre National de la Recherche Scientifique (CNRS) veranstalteten „Conferences Jacques Monod”︁ war dem Thema „Intracellular Redox Controls by Thioredoxin and Glutaredoxin Systems”︁ gewidmet. Zu der Konferenz kamen im Juli in der Biologischen Station Roscoff (Bretagne) etwa 100 Wissenschaftler aus 15 Ländern zusammen.     

Zur Kristallstruktur von SmZrF7 mit einem Anhang über EuSnF7 und YSnF7

On the Crystal Structure of SmZrF₇ with an Appendix on EuSnF₇ and YSnF₇ SmZrF₇ again was obtained as colourless single crystals and investigated by X-ray methods: It crystallizes in space group P 2₁/c-C (Nr. 14; P 2₁/n) with a = 1 140.9(2) pm, b = 574.6(1) pm, c = 914,4(2) pm, β = 107.32(2)°, Z = 4 but not in space group P 2₁-C (Nr. 4) [1]. In addition EuSnF₇ and YSnF₇ are isotypic with the following lattice constants: EuSnF₇: a = 1 121.8(2) pm, b = 563.7(1) pm, c = 901.7(1) pm, β = 107.35(2)° with Z = 4; YSnF₇: a = 1 106.7(2) pm, b = 556.4(1) pm, c = 884.7(1) pm, β = 107.51(1)° and Z = 4 (Powder data).     

Über Chalkogenolate. 139. Untersuchungen über Dialkylester von Chalkogenokohlensäuren. 2. O,Se- und S,Se-Dialkylmonothiomonoselenocarbonate

On Chalcogenolates. 139. Studies on Dialkyl Esters of Chalcogenocarbonic Acids. 2. O,Se- and S, Se-Dialkyl Monothiomonoselenocarbonates The hitherto unknown esters RSe? CS? OR′, where R = C₂H₅, ⁿC₃H₇ and R′ = C₂H₅, ⁿC₃H₇, are formed by reaction of NaSeR with Cl? CS? OR′ and of RSe? CS? Cl with HOR′. At the first time, the esters RSe? CO? SR′ with R = R′ = C₂H₅, ⁿC₃H₇ have been prepared by reaction between NaSeR and Cl? CO? SR′. The compounds have been characterized by means of diverse spectroscopic methods.     

Massenspektrometrische Untersuchungen der Gasphase über As2O5

Mass Spectrometric Investigations of the Gaseous Phase above As₂O₅ The gaseous phase above solid As₂O₅ has been investigated in the temperature range between 862 and 939 K by mass spectrometric methods. The presence of gaseous As₄O_x-molecules (6 ≤ × ≤ 10) and O₂ was proved. Using the partial pressures, heats of formation (Δ_fH°(900), kJ · mol^?1; 2nd law calculations) were calculated (As₄O_7,g: -1209,5; As₄O_8,g: -1361,9; As₄O_9,g: -1495,4; As₄O_10,g: -1618,8). The enthalpy of formation of solid As₂O₅ was determined to be Δ_fH°(298) = ?1007,9 kJ · mol^?1. The thermochemical data of the As₄O_x-molecules are discussed in context with possibilities for the synthesis of solid As₄O₁₀.     

Notiz über den α-LiFeO2-Typ: NaPrO2 und NaTbO2

On the α-LiFeO₂ Type of Structure: NaPrO₂ and NaTbO₂ For the first time transparent light-green single crystals of NaPrO₂ [from PrO_1,833: KO_0,50:NaO_0,50 = 1:1.1:1.2 Ni-cylinder, 1000°C, 20 d] and colourless single crystals of hitherto unknown NaTbO₂ [from Na₂TbO₃, Ni-cylinder, 1000°C, 10 d] have been prepared and investigated by X-ray. The tetragonal α-LiFeO₂-type is confirmed. [NaPrO₂: a = 476.19(3), c = 1096.09(11) pm, c/a = 2.30; 107 I₀ (hkl); R = 4.25% R_w = 3.39%, MoKα; NaTbO₂: a = 463.11(3), c = 1037.39(12) pm, c/a = 2.24; 103 I₀ (hkl); R = 3.54%; R_w = 2,81%; MoKα; both space group I4₁/a m d; fourcircle diffractometer Philips PW 1100]. The Madelung Part of Lattice Energy, MAPLE, and the peculiarities of this type of structure are discussed.     

Über Chalkogenocarbonate. XLVIII. Untersuchungen über die lonen CS2Se2− und CSSe und über Kohlenstoffsulfid-hydrogensulfid-hydrogenselenid SC(SH)(SeH)

CS₂ forms with BaSe in aqueous solution the compound BaCS₂Se. The reaction of CSe₂ with BaS leads to mixed crystals of BaCSSe_a and BaCSe₃. The compounds were investigated by chemical, X-ray and IR-spectroscopical methods. Assignments of all normal vibrations of the ions CS₂Se^2- and CSSe were possible. The conductivity of CS₂Se^2- in aqueous solution was determine. By interaction of BaCS²Se with HCl the acid H₂CS₂SE (red oil) was prepared in form of its S, Se-protonated isomer; fast decomposition to H₂ Se and CS₂ occurs. From conductivity measurements it is concluded that the decomposition of H₂CS₂Se in aqueous solution is a first-order reaction via the anion HCS₂Se^?. Half-lifes and activation energy are given. The dissociation constants K_a1 and K_a2 were determind and thermodynamic data of the dissociation calculate. Date see ?Inhaltsübersicht”?.