Polyol-Metall-Komplexe. XIII [1]. Na2[Be(C4H6O3)2] · 5H2O und Na2[Pb(C4H6O3)2] · 3H2O – zwei homoleptische Bis-polyolato-metallate mit Beryllium und mit Blei

Polyol Metal Complexes. XIII. Na₂[Be(C₄H₆O₃)₂] · 5H₂O and Na₂[Pb(C₄H₆O₃)₂] · 3H₂O – Two Homoleptic Bis Polyolato Metallates with Beryllium and with Lead Na₂[Be(C₄H₆O₃)₂] · 5H₂O ( 1 ) and Na₂[Pb(C₄H₆O₃)₂] · 3H₂O ( 2 ) crystallize from concentrated, alkaline aqueous solutions. The polyol anhydroerythritol is deprotonated twice in the mononuclear, homoleptic complex anions. The preference of beryllium for the binding of cis-furanoid diols is shown. In 2 , a stereochemically active lone pair at the central atom is the reason for the construction of low dimensional aggregates from three plumbate and three sodium ions.     

Solid‐Liquid Equilibria in the Quinary Na+, K+//Cl−, SO2−4, B4O2−7‐H2O System at 298 K

The solid‐liquid equilibria in the quinary system Na⁺, K⁺//Cl^?, SO^2?₄, B₄O^2?₇‐H₂O at 298 K had been studied experimentally using the method of isothermal solution saturation. Solubilities and densities of the solution of the quinary system were measured experimentally. Based on the experimental data, the dry‐salt phase diagram and water content diagram of the quinary system were constructed, respectively. In the equilibrium diagram of the quinary system Na⁺, K⁺//Cl^?, SO^2?₄, B₄O^2?₇‐H₂O at 298 K, there are five invariant points F1, F2, F3, F4 and F5; eleven univariant curves E1F1, E2F2, E3F3, E4F5, E5F2, E6F4, E7F5, F1F4, F2F4 F1F3 and F3F5, and seven fields of crystallization saturated with Na₂B₄O₇ corresponding to Na₂SO₄, Na₂SO₄·10H₂O, Na₂SO₄·3K₂SO₄ (Gla), K₂SO₄, K₂B₄O₇·4H₂O, NaCl and KCl. The experimental results show that Na₂SO₄·3K₂SO₄ (Gla), K₂SO₄ and K₂B₄O₇·4H₂O have bigger crystallization fields than other salts in the quinary system Na⁺, K⁺//Cl^?, SO^2?₄, B₄O^2?₇‐H₂O at 298 K.     

Beiträge zur Chemie der Alkylverbindugen von Übergangsmetallen. XXIX. Dibenzylmangan – Darstellung und Reaktionen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXIX. Dibenzyl Manganese – Preparation and Reactions Manganese(II) acetylacetonate reacts with tribenzyl aluminium and dibenzyl magnesium forming the yellow complexes 3(C₆H₅CH₂)₂Mn · Al(acac)₃ and (C₆H₅CH₂)₂Mn · Mg(acac)₂ Dibenzyl manganese is also formed at the reaction of dibenzyl magnesium or benzyl magnesium chloride with MnCl₂ · 1.5 THF and was separated as the dioxan complex (C₆H₅CH₂)₂Mn · 2C₄H₈O₂, the ligands of which can be removed to a great extent in vacuum. Dibenzyl manganese reacts with CO₂, CS₂ and SO₂ with insertion into the Mn–C-bonds. The corresponding manganese compounds were isolated and furtherly characterized.     

Alcoholysis of (2-methoxycarbonyl)ethyltin compounds

Under acid or base catalysis, di(2-alkoxycarbonylethyl)tin dichlorides of various R groups, (ROCOCH₂CH₂)₂SnCl₂, can be prepared conveniently in high yield by alcoholysis of (CH₃OCOCH₂CH₂)₂SnCl₂ in various alcohols, ROH (R = C₂H₅, C₄H₉, iso-C₄H₉, C₅H₁₁, C₆H₅CH₂, C₄H₉CH(C₂H₅)CH₂). When excess acid or base is present in the aqueous solution, (ROCOCH₂CH₂)₂SnCl₂ eliminate ROH and precipitate as C₆H₈O₄Sn regardless of the R group. C₆H₈O₄Sn can be converted into various (ROCOCH₂CH₂)₂SnCl₂ derivatives on dissolving in alcoholic HCl solutions.     

Eight salt forms of sulfadiazine

Proton transfer to the sulfa drug sulfadiazine [systematic name: 4‐amino‐N‐(pyrimidin‐2‐yl)benzenesulfonamide] gave eight salt forms. These are the monohydrate and methanol hemisolvate forms of the chloride (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium chloride monohydrate, C₁₀H₁₁N₄O₂S⁺·Cl⁻·H₂O, (I), and 2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium chloride methanol hemisolvate, C₁₀H₁₁N₄O₂S⁺·Cl⁻·0.5CH₃OH, (II)); a bromide monohydrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium bromide monohydrate, C₁₀H₁₁N₄O₂S⁺·Br⁻·H₂O, (III)), which has a disordered water channel; a species containing the unusual tetraiodide dianion [bis(2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium) tetraiodide, 2C₁₀H₁₁N₄O₂S⁺·I₄²⁻, (IV)], where the [I₄]²⁻ ion is located at a crystallographic inversion centre; a tetrafluoroborate monohydrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium tetrafluoroborate monohydrate, C₁₀H₁₁N₄O₂S⁺·BF₄⁻·H₂O, (V)); a nitrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium nitrate, C₁₀H₁₁N₄O₂S⁺·NO₃⁻, (VI)); an ethanesulfonate {4‐[(pyrimidin‐2‐yl)sulfamoyl]anilinium ethanesulfonate, C₁₀H₁₁N₄O₂S⁺·C₂H₅SO₃⁻, (VII)}; and a dihydrate of the 4‐hydroxybenzenesulfonate {4‐[(pyrimidin‐2‐yl)sulfamoyl]anilinium 4‐hydroxybenzenesulfonate dihydrate, C₁₀H₁₁N₄O₂S⁺·HOC₆H₄SO₃⁻·2H₂O, (VIII)}. All these structures feature alternate layers of cations and of anions where any solvent is associated with the anion layers. The two sulfonate salts are protonated at the aniline N atom and the amide N atom of sulfadiazine, a tautomeric form of the sulfadiazine cation that has not been crystallographically described before. All the other salt forms are instead protonated at the aniline group and on one N atom of the pyrimidine ring. Whilst all eight species are based upon hydrogen‐bonded centrosymetric dimers with graph set R₂²(8), the two sulfonate structures also differ in that these dimers do not link into one‐dimensional chains of cations through NH₃‐to‐SO₂ hydrogen‐bonding interactions, whilst the other six species do. The chloride methanol hemisolvate and the tetraiodide are isostructural and a packing analysis of the cation positions shows that the chloride monohydrate structure is also closely related to these.     

Sodium di­hydrogen tris­(cyclo­propane­carboxyl­ate)

The title acid salt, Na⁺·C₄H₅O₂^?·2C₄H₆O₂, contains finite anions in which two cyclo­propanoic acid mol­ecules are hydrogen bonded to a cyclo­propanoate residue. Each such anion interacts with four different Na⁺ cations.     

Sodium hydrogen bis­(phenoxy­acetate)

In the title compound, Na⁺·H⁺·2C₈H₇O₃⁻, the anion contains a short Speakman-type hydrogen bond [O⃛O = 2.413 (2) Å]. The anions and the Na atoms lie across twofold axes.     

The Sodium (Iso)Cyanurates Nax[H3–xC3N3O3]·yH2O (x = 1–3, y = 0, 1): A Key‐Series for Understanding the Crystal Chemistry of Metal (Iso)Cyanurates

The (iso)cyanurates Na[H₂C₃N₃O₃] · H₂O, Na₂[HC₃N₃O₃] · H₂O, Na₂[HC₃N₃O₃], and Na₃[C₃N₃O₃] were synthesized phase pure from Na₂CO₃ · 10H₂O, NaOH, and cyanuric acid, respectively, in aqueous solution by carefully adjusting the crystallization conditions. The crystal structures of all compounds were determined by single‐crystal X‐ray diffraction {Na₂[HC₃N₃O₃] · H₂O: P1 , a = 3.51660(10) Å, b = 7.8300(3) Å, c = 11.3966(4) Å, α = 86.4400(10)°, β = 85.5350(10)°, γ = 85.0720(10)°, Z = 2, R₁ = 0.030, wR₂ = 0.078; Na₂[HC₃N₃O₃]: Pnma, a = 6.3409(6) Å, b = 12.2382(13) Å, c = 6.5919(7) Å, Z = 4, R₁ = 0.045, wR₂ = 0.079; Na₃[C₃N₃O₃]: R3 c, a = 11.7459(3) Å, c = 6.5286(3) Å, Z = 3, R₁ = 0.039, wR₂ = 0.066}. The structures show ribbons (Na[H₂C₃N₃O₃] · H₂O), dimers (Na₂[HC₃N₃O₃] · H₂O), chains (Na₂[HC₃N₃O₃]), or columns (Na₃[C₃N₃O₃]) of hydrogen‐bonded and parallel stacked (iso)cyanurate anions. These motifs are shown to be characteristic for certain degrees of protonation and hydration, and all (iso)cyanurate crystal structures found so far were classified accordingly. X‐ray powder patterns, thermogravimetry curves, IR and UV/Vis spectra were measured for all compounds.     

Physicochemical Analysis of the System Zr(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>–Na<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>SO<Subscript>4</Subscript>–H<Subscript>2</Subscript>O at 25°С

The solubility in the quaternary water–salt system Zr(SO₄)₂ · 4Н₂О–Na₂SO₄–H₂SO₄–H₂O at 25°C was studied. It was found that, in the system, there is crystallization of not only Na₂SO₄ and Zr(SO₄)₄ · 4H₂O, but also sodium sulfate zirconates Na₂Zr(SO₄)₂(OH)₂ · 0.3H₂O, Na₄Zr(SO₄)₄ · 3H₂O, and Na₂Zr(SO₄)₂ · 3H₂O and two new compounds, S₁ and S₂, which are presumably Na₂ZrO(SO₄)₂ · 2H₂O and Na₂Zr₂O₂(SO₄)₃ · 6H₂O.     

The design of novel metronidazole benzoate structures: exploring stoichiometric diversity

The use of supramolecular synthons as a strategy to control crystalline structure is a crucial factor in developing new solid forms with physicochemical properties optimized by design. However, to achieve this objective, it is necessary to understand the intermolecular interactions in the context of crystal packing. The feasibility of a given synthon depends on its flexibility to combine the drug with a variety of coformers. In the present work, the imidazole–hydroxy synthon is investigated using as the target molecule benzoylmetronidazole [BZMD; systematic name 2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)ethyl benzoate], whose imidazole group seems to be a suitable acceptor for hydrogen bonds. Thus, coformers with carboxylic acid and phenol groups were chosen. According to the availability of binding sites presented in the coformer, and considering the proposed synthon and hydrogen‐bond complementarity as major factors, different drug–coformer stoichiometric ratios were explored (1:1, 2:1 and 3:1). Thirteen new solid forms (two salts and eleven cocrystals) were produced, namely BZMD–benzoic acid (1/1), C₁₃H₁₃N₃O₄·C₇H₆O₂, BZMD–β‐naphthol (1/1), C₁₃H₁₃N₃O₄·C₁₀H₈O, BZMD–4‐methoxybenzoic acid (1/1), C₁₃H₁₃N₃O₄·C₈H₈O₃, BZMD–3,5‐dinitrobenzoic acid (1/1), C₁₃H₁₃N₃O₄·C₇H₄N₂O₆, BZMD–3‐aminobenzoic acid (1/1), C₁₃H₁₃N₃O₄·C₇H₇NO₂, BZMD–salicylic acid (1/1), C₁₃H₁₃N₃O₄·C₇H₆O₃, BZMD–maleic acid (1/1) {as the salt 1‐[2‐(benzoyloxy)ethyl]‐2‐methyl‐5‐nitro‐1H‐imidazol‐3‐ium 3‐carboxyprop‐2‐enoate}, C₁₃H₁₄N₃O₄⁺·C₄H₃O₄^?, BZMD–isophthalic acid (1/1), C₁₃H₁₃N₃O₄·C₈H₆O4, BZMD–resorcinol (2/1), 2C₁₃H₁₃N₃O₄·C₆H₆O₂, BZMD–fumaric acid (2/1), C₁₃H₁₃N₃O₄·0.5C₄H₄O₄, BZMD–malonic acid (2/1), 2C₁₃H₁₃N₃O₄·C₃H₂O₄, BZMD–2,6‐dihydroxybenzoic acid (1/1) {as the salt 1‐[2‐(benzoyloxy)ethyl]‐2‐methyl‐5‐nitro‐1H‐imidazol‐3‐ium 2,6‐dihydroxybenzoate}, C₁₃H₁₄N₃O₄⁺·C₇H₅O₄^?, and BZMD–3,5‐dihydroxybenzoic acid (3/1), 3C₁₃H₁₃N₃O₄·C₇H₆O₄, and their crystalline structures elucidated, confirming the robustness of the selected synthon.     

Solution polymerization of trioxane catalyzed by stannic chloride

The polymerization of trioxane catalyzed by stannic chloride (SnCl₄) in ethylene dichloride was studied and compared with the results obtained with boron trifluoride etherate, BF₃·O(C₂H₅)₂, as catalyst. Under the same conditions, the polymerization rate was larger with SnCl₄ than with BF₃·O(C₂H₅)₂, while at a fixed polymer yield the molecular weight of the polymer obtained by SnCl₄ was lower than with the BF₃·O(C₂H₅)₂ catalyzed reaction. The overall activation energy of trioxane polymerization with SnCl₄ was 11.0 ± 0.8 kcal/mole. The kinetic orders of catalyst and monomer were determined to be close to 2 and 4, respectively. A certain amount of tetraoxane was also produced in an early stage of the polymerization with SnCl₄ similar to BF₃·O(C₂H₅)₂-catalyzed reaction. However, the maximum amount of tetraoxane produced at 30°C was larger with SnCl₄ than with BF₃·O(C₂H₅)₂. In addition, a ten-membered ring compound (pentoxane) was isolated in the solution polymerization of trioxane catalyzed by both SnCl₄ and BF₃·O(C₂H₅)₂. The confirmation of pentoxane formation is strong evidence for the back-biting reaction mechanism.     

Study on the non-isothermal kinetics of decomposition of 4Na<Subscript>2</Subscript>SO<Subscript>4</Subscript>·2H<Subscript>2</Subscript>O<Subscript>2</Subscript>·NaCl

The non-isothermal decomposition kinetics of 4Na₂SO₄·2H₂O₂·NaCl have been investigated by simultaneous TG-DSC in nitrogen atmosphere and in air. The decomposition processes undergo a single step reaction. The multivariate nonlinear regression technique is used to distinguish kinetic model of 4Na₂SO₄·2H₂O₂·NaCl. Results indicate that the reaction type Cn can well describe the decomposition process, the decomposition mechanism is n-dimensional autocatalysis. The kinetic parameters, n, A and E are obtained via multivariate nonlinear regression. The n ^th-order with autocatalysis model is used to simulate the thermal decomposition of 4Na₂SO₄·2H₂O₂·NaCl under isothermal conditions at various temperatures. The flow rate of gas has little effect on the decomposition of 4Na₂SO₄·2H₂O₂·NaCl.     

DSC study of melting and solidification of salt hydrates

Most salt hydrates, especially those proposed for thermal-energy-storage applications, melt incongruently. In static systems, this property often leads to differences between the enthalpy of fusion and enthalpy of solidification. By means of differential scanning calorimetry (DSC), these differences have been determined for several salt hydrates. For Na₂SO₄ · 10 H₂O, the enthalpy of solidification at or near the peritectic temperature is never more than 60% of the enthalpy of fusion; further cooling leads to a second phase transition at a temperature corresponding to eutectic melting of mixtures of ice and this hydrate. This asymmetrical melting and freezing behavior of Na₂SO₄ · 10 H₂O decreases its potential as an energy-storing medium and also limits its usefulness for temperature calibration of DSC instruments. Sodium pyrophosphate decahydrate, Na₄P₂O₇ · 10 H₂O, although in some ways a higher temperature analog of Na₂SO₄ · 10 H₂O, exhibited a smaller discrepancy between the enthalpies of fusion and of solidification; its relatively high transition temperature permits a more rapid solidification reaction than is the case for Na₂SO₄ · 10 H₂O. For Mg(NO₃)₂ · 6 H₂O, a congruently melting compound, the magnitude of ΔH of crystallization equalled ΔH of fusion, even when supercooling occurred; a solid-state transition at 73°C, with ΔH = 2.9 cal g^?1, was detected for this hydrate. MgCl₂ · 6 H₂O, which melts almost congruently, exhibited no disparity between ΔH of crystallization and ΔH of fusion. CuSO₄ · 5 H₂O and Na₂B₄O₇ · 10 H₂O exhibited marked disparities. Na₂B₄O₇ · 10 H₂O formed metastable Na₂B₄O₇sd 5 H₂O at the phase transition; this was derived from the transition temperature and verified by relating the observed ΔH of transition to heats of hydration. Peritectic solidification of hydrates can be viewed as a dual process: crystallization from the liquid solution and reaction of the lower hydrate (or anhydrate) with the solution; where ΔH of solidification appears to be less in magnitude than the ΔH of fusion, the difference can be attributed to slower reaction rate between solution and the lower hydrate. New or previously unreported values for ΔH of fusion obtained in this study were, in cal g^?1: Mg(NO₃)₂ · 6 H₂O, 36; Na₄P₂O₇ · 10 H₂O, 59; CuSO₄ · 5 H₂O, 32; Na₂B₄O₇ · 10 H₂O, 33.     

Thermodynamics of sodium 5-methylisophthalic acid monohydrate and sodium isophthalic acid hemihydrate

Two crystal samples, sodium 5-methylisophthalic acid monohydrate (C₉H₆O₄Na₂·H₂O, s) and sodium isophthalic acid hemihydrate (C₈H₄O₄Na₂·1/2H₂O, s), were prepared from water solution. Low-temperature heat capacities of the solid samples for sodium 5-methylisophthalic acid monohydrate (C₉H₆O₄Na₂·H₂O, s) and sodium isophthalic acid hemihydrate (C₈H₄O₄Na₂·1/2H₂O, s) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 379 K. The experimental values of the molar heat capacities in the measured temperature region were fitted to a polynomial equation on molar heat capacities (C _p,m) with the reduced temperatures (X), [X = f(T)], by a least-squares method. Thermodynamic functions of the compounds (C₉H₆O₄Na₂·H₂O, s) and (C₈H₄O₄Na₂·1/2H₂O, s) were calculated based on the fitted polynomial equation. The constant-volume energies of combustion of the compounds at T = 298.15 K were measured by a precise rotating-bomb combustion calorimeter to be Δ_c U(C₉H₆O₄Na₂·H₂O, s) = −15428.49 ± 4.86 J g⁻¹ and Δ_c U(C₈H₄O₄Na₂·1/2H₂O, s) = −13484.25 ± 5.56 J g⁻¹. The standard molar enthalpies of formation of the compounds were calculated to be Δ _f H _m ^θ (C₉H₆O₄Na₂·H₂O, s) = −1458.740 ± 1.668 kJ mol⁻¹ and Δ _f H _m ^θ (C₈H₄O₄Na₂·1/2H₂O, s) = −2078.392 ± 1.605 kJ mol⁻¹ in accordance with Hess’ law. The standard molar enthalpies of solution of the compounds, Δ _sol H _m ^θ (C₉H₆O₄Na₂·H₂O, s) and Δ _sol H _m ^θ (C₈H₄O₄Na₂·1/2H₂O, s), have been determined as being −11.917 ± 0.055 and −29.078 ± 0.069 kJ mol⁻¹ by an RD496-2000 type microcalorimeter. In addition, the standard molar enthalpies of hydrated anion of the compounds were determined as being Δ _f H _m ^θ (C₉H₆O₄ ²⁻, aq) = −704.227 ± 1.674 kJ mol⁻¹ and Δ _f H _m ^θ (C₈H₄O₄Na₂ ²⁻, aq) = −1483.955 ± 1.612 kJ mol⁻¹, from the standard molar enthalpies of solution and other auxiliary thermodynamic data through a thermochemical cycle.     

Molten potassium pyrosulfate: The reactions of seven metal oxalates

The reactions of Li₂C₂O₄, Na₂C₂O₄, K₂C₂·H₂O, CaC₂·H₂O, ZnC₂O₄, La₂(C₂O₄)₃ and K₂TiO(C₂O₄)₂· 2H₂O with K₂S₂O₇ were investigated using thermal methods of analysis. Reaction products were analysed by various techniques. It was found that anhydrous oxalates reacted with K₂S₂O₇, evolving a mixture of CO₂ and CO with the formation of K₂SO₄ and the corresponding metal sulfates, which, in the reactions of ZnC₂O₄ and K₂TiO(C₂O₄)₂ 2H₂O, probably existed as K₂[Zn(SO₄)₂] and K₄[Ti(SO₄)₄], respectively. Water was found to be an additional product in the hydrated metal oxalate reactions. The stoichiometries of these reactions have been established from the thermogravimetric and acidimetric results.     

Komplexchemie polyfunktioneller Liganden. XXXI. Komplexe des Tetrakis(diphenylphosphorylmethyl)-methan mit FeCl3, SnCl4 und SbCl5

Complex Chemistry of Polyfunctional Ligands. XXXI. Complexes of Tetrakis(diphenylphosphorylmethyl) methane with FeCl₃, SnCl₄, and SbCl₅ C[CH₂P(O)(C₆H₅)₂]₄ forms with FeCl₃ the compounds C[CH₂P(O)(C₆H₅)₂]₄ · 2FeCl₃ and C[CH₂P(O)(C₆H₅)₂]₄ · 4 FeCl₃. From their IR spectra ionic, spirocyclic structures have been derived. C[CH₂P(O)(C₆H₅)₂]₄ yields with SnCl₄ and SbCl₅ also spirocyclic compounds of the composition C[CH₂P(O)(C₆H₅)₂]₄ · 2 SnCl₄ and C[CH₂P(O)(C₆H₅)₂]₄ · 4 SbCl₅, but the SnCl₄ derivative has a nonionic structure.     

Hybrid Inorganic‐Organic Frameworks: Synthesis and Crystal Structures of RbFe(SO4)(C2O4)0.5·H2O and CsM(SO4)(C2O4)0.5·H2O (M = Mn,Fe)

Three new alkali metal transition metal sulfate‐oxalates, RbFe(SO₄)(C₂O₄)_0.5 · H₂O and CsM(SO₄)(C₂O₄)_0.5 · H₂O (M = Mn, Fe) were prepared through hydrothermal reactions and characterized by single‐crystal X‐ray diffraction, solid state UV/Vis/NIR diffuse reflectance spectroscopy, infrared spectra, thermogravimetric analysis, and powder X‐ray diffraction. The title compounds all crystallize in the monoclinic space group P2₁/c (no. 14) with lattice parameters: a = 7.9193(5), b = 9.4907(6), c = 8.8090(6) Å, β = 95.180(2)°, Z = 4 for RbFe(SO₄)(C₂O₄)_0.5 · H₂O; a = 8.0654(11), b = 9.6103(13), c = 9.2189(13) Å, β = 94.564(4)°, Z = 4 for CsMn(SO₄)(C₂O₄)_0.5 · H₂O; and a = 7.9377(3), b = 9.5757(4), c = 9.1474(4) Å, β = 96.1040(10)°, Z = 4 for CsFe(SO₄)(C₂O₄)_0.5 · H₂O. All compounds exhibit three‐dimensional frameworks composed of [MO₆] octahedra, [SO₄]^2– tetrahedra, and [C₂O₄]^2– anions. The alkali cations are located in one‐dimensional tunnels.     

Crystal Structures and Raman Spectra of cis‐[SnCl4(H2O)2]·2H2O,cis‐[SnCl4(H2O)2]·3H2O, [Sn2Cl6(OH)2(H2O)2]·4H2O,and [HL][SnCl5(H2O)]·2.5H2O (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime,C18H18N4O2)

The complexes cis‐[SnCl₄(H₂O)₂]·2H₂O ( 1 ), [Sn₂Cl₆(OH)₂(H₂O)₂]·4H₂O ( 3 ), and [HL][SnCl₅(H₂O)]·2.5H₂O ( 4 ) were isolated from a CH₂Cl₂ solution of equimolar amounts of SnCl₄ and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C₁₈H₁₈N₄O₂) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P2₁, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl₄(H₂O)₂]·3H₂O ( 2 ): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3 : a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P2₁/c and Z = 4.     

Na2Mg(SO3) · 2H2O. Ein neues ternäres Magnesiumsulfit Kristallstruktur,schwingungsspektroskopische und thermoanalytische Untersuchungen

Na₂Mg(SO₃)₂ · 2H₂O. A New Ternary Magnesium Sulfite. Crystal Structure, Thermoanalytical, I.R., and Raman Data Single crystals of the hitherto unknown Na₂Mg(SO₃)₂ · 2 H₂O have been obtained by crystallization from Mg(HSO₃)₂ solutions saturated with NaCl and with the technique of gel crystallization. The crystal structure of the triclinic Na₂Mg(SO₃)₂ · 2 H₂O (P1 , Z = 1, a = 752.4(1), b = 590.3(1), c = 517.8(1) pm, α = 106.25(1), β = 109.80(1), and γ = 101.49(1)°) has been determined using single crystal X-ray diffraction data. The Mg? O distances of the nearly regular MgO₆ octahedra are between 206.6 and 210.5 pm. The MgO₆ octahedra are connected by sulfite bridges forming chains in [001], which are held together by strong hydrogen bridges. The SO₃^2? ions have nearly C_3v symmetry. The results of thermoanalytical and I.R. and Raman spectroscopic measurements are reported and discussed. The O? D stretching modes of HDO molecules in partially deuterated samples show that the water molecules differ strongly from C_2v symmetry.     

A combined method for investigating solubility and determining the composition of equilibrium solid phases saturating eutonic solutions in a NaCl-Na2SO4-Na2CO3-H2O system at 50°C

The composition of equilibrium solid phases NaCl, Na₂SO₄, Na₂CO₃ · 2Na₂SO₄ (berkeyite) and NaCl, Na₂CO₃ · H₂O, Na₂CO₃ · 2Na₂SO₄ (without preparative determination), saturating E₁ and E₂ eutonic solutions respectively, was established via nonvariant area boundary determination in a NaCl-N₂SO₄- Na₂CO₃-H₂O system at 50°C with the use of a combined method.