An unprecedented 2D isopolymolybdate with (3·4)(3·5·8)(3·4·5·6·8)(3·4·5·6) topology

A novel two-dimensional molybdenum oxide polymer, [Mo₄O₁₃]_n · 2nH₃O, has been prepared under specific hydrothermal conditions and characterized by IR spectroscopy and TG analysis. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a (3, 4, 5, 6)-connected 2D layer structure with (3²·4)(3²·5³·8)(3·4²·5⁴·6·8²)(3⁴·4³·5⁴·6⁴) topology, which is constructed by two parallel molybdenum oxide dimeric chains (Mo₂O₁₀)_n bound together by the dimer of Mo₂O₉ subunits via the sharing of corners. Additionally, the electrochemistry activity of compound 1 is also reported.     

Zum Konformationsverhalten isomerer Phenylpyrimidine — Molekül- und Kristallstruktur von 5-Chlor-2-(4-n-hexyloxyphenyl)-pyrimidin

On the Conformational Behaviour of Isomeric Phenyl Pyrimidines — Molecular and Crystal Structure of 5-Chloro-2-(4-n-hexyloxyphenyl)-pyrimidine The title compound crystallizes in the triclinic space group P1 with a = 979.6(1) pm, b = 1048.8(3) pm, c = 1629.9(1) pm, α = 89.51(1)°, β = 100.62(1)°, γ = 71.50(1)° and four molecules per unit cell. The structure has been solved by direct methods and refined to a final R value of 0.058. The molecules adopt a fully stretched and nearly planar form and show a parallel arrangement in the crystal lattice. The results are discussed in relation to the conformational and mesomorphic behaviour of isomeric substituted phenyl pyrimidines.     

Zum Konformationsverhalten substituierter Benzoesäurephenylester - Molekül- und Kristallstruktur der nematogenen Verbindung 4-n-Pentoxybenzoesäure-4′-(ß-cyanethyl)-phenylester

On the Conformational Behaviour of Substituted Phenylbenzoates - Molecular and Crystal Structure of the Nematogenic Compound 4′-(ß-Cyanoethyl)-phenyl-4-n-pentoxybenzoate The title compound crystallizes in the monoclinic space group P2₁/n with a = 1567.6(2) pm, b = 915.5(1) pm, c = 1459.1(1) pm, β = 115.30(1)°, and four molecules per unit cell. The structure has been solved by direct methods and refined to R = 0.104. The molecules adopt a markedly stretched form and show a parallel arrangement of their long axes in the crystal lattice. The molecular and crystal structure is discussed in relation to the mesomorphic behaviour of the compound. A theoretical conformational analysis has been performed for the isolated phenylbenzoate molecule using the EPEN/2 method, its results are compared with the experimental torsion angles in a series of substituted phenylbenzoates.     

Chromatographischer und spektroskopischer Vergleich des Autoxidationsprozesses von Öl- und Elaidinsäure

Chromatographic and Spectroscopic Comparison of the Autoxidation Process of Oleic and Elaidic Acid The autoxidation process of cis-9-octadecenoic and trans-9-octadecenoic acid was studied using thin-layer chromatography, gasliquid chromatography, nuclear magnetic resonance spectroscopy and infra-red spectroscopy. On the basis of results obtained and by comparison with the “classical methods”, such as the course of peroxide value, and changes in acid value and iodine value, a scheme has been proposed to characterize the initial phase of the autoxidation process of oleic and elaidic acids.     

Kristall- und Molekülstruktur des 4,5-Dibenzoylseleno-1,3-diselenol-2-selon

Crystal and Molecular Structure of 4,5-Dibenzoylseleno-1,3-diselenole-2-selone The crystal and molecular structure of 4,5-dibenzoylseleno-1,3-diselenole-2-selone is described. The compound crystallizes in the monoclinic space group P2₁/c with a = 9.704, b = 10.839, c = 17.726 [Å], β = 93.43° and Z = 4. The structure is compared with that of the analogous „all-sulfur”︁ compound. The crystal packing of the heterocycle studied shows surprisingly short intermolecular distances between neighbouring selone groups.     

Synthesen mit 1,3-Dithietanen. IX [1]. Reaktionen des 2,4-Bis-(äthoxycarbonyl-cyan-methylen)-1,3-dithietans und des 2-Cyan-3,3-bis-(methylmercapto)-acrylsäureäthylesters mit Carbonsäurehydraziden

Syntheses with 1,3-Dithietanes. IX. Reactions of 2,4-Bis(ethoxycarbonyl-cyano-methylene)-1, 3-dithietane and of Ethyl 2-cyano-3, 3-bis(methylmercapto)acrylate with Carboxylic Acid Hydrazides 2, 4-Bis(ethoxycarbonyl-cyano-methylene)-1, 3-dithietane 1 reacts with carboxylic acid hydrazides to yield ethyl 1-aroyl-5-imino-3-mercapto-Δ³-pyrazoline-4-carboxylates 4. 4 and hydrazin hydrate yield ethyl 1-aroyl-5-imino-3-hydrazino-Δ³-pyrazoline-4-carboxylates 5 which are transformed by heat to the ethyl 3(5)-amino-5(3)-(2-aroyl-hydrazino)pyrazole-4-carboxylates 6 . The reaction of ethyl 2-cyano-3,3-bis(methylmercapto)acrylate 8 with carboxylic acid hydrazides yield ethyl 1-aroyl-3-amino-5-methylmercapto-pyrazole-4-carboxylates 10 . Compounds 10 are compared with S-methyl derivatives of 4 .     

Dielectric and dilatometric studies of (CH3)2NH2Ga(SO4)2 · 6H2O (DMAGaS)

The results of dielectric, pyroelectric, spontaneous polarization and dilatometric investigations in the temparature interval 110 K-295 K are presented for DMAGaS crystal. At both phase transition temperature, 136 K and 116 K, discontinuous changes of dielectric permittivity, spontaneous polarization and length of bars are observed. Temperature dependences of alongation along the ferroelectric direction and of spontaneous polarization are quite similar.     

Ein Beitrag zum Bindevermögen des Natriumpolyphosphates (NaPO3)x · H2O für Ca- und Mg-Ionen,I. Mitteilung

The Binding Capacity of Sodium Polyphosphate (NaPO₃)_x · H₂O for Ca- and Mg-ions: Part I The binding capacity of sodium polyphosphate (NaPO₃)_x · H₂O for cations, especially for those of calcium or magnesium, in solutions of strong and weak electrolytes of varying concentrations, is dependent to a large extent on the ?stoichiometric”? activity coefficient of the foreign electrolyte and its hydration state. A functional relation was found for the ?relative”? binding capacity which is similar to the limiting law of Debye-Hückel-relation between activity coefficients and ionic concentration of the dissolved electrolyte. The binding capacity can be intensified or diminished by the solution partners.     

The lime-silica-water system: Equilibria at bulk calcium/silicon ratios of 1·5–2·5 AT 180–250°C

The stability relationships of xonotlite, foshagite and hillebrandite relative to kilchoanite and calcio-chondrodite have been studied under saturated steam pressures at 180° and 250°. Kilchoanite was unstable relative to xonotlite plus hillebrandite at 180°, or to foshagite plus hillebrandite at 250°; calcio-chondrodite was unstable relative to hillebrandite plus some more lime-rich phase, possibly Ca(OH)₂, at both temperatures. Foshagite was stable relative to xonotlite plus hillebrandite at 250°, but unstable relative to these phases at 180°.