Syntheses and Structures of Na2Mg3(OH)2(SO4)3·4H2O and K2Mg3(OH)2(SO4)3·2H2O

The crystal structures of Na₂Mg₃(OH)₂(SO₄)₃ · 4H₂O and K₂Mg₃(OH)₂(SO₄)₃ · 2H₂O, were determined from conventional laboratory X‐ray powder diffraction data. Synthesis and crystal growth were made by mixing alkali metal sulfate, magnesium sulfate hydrate, and magnesium oxide with small amounts of water followed by heating at 150 °C. The compounds crystallize in space group Cmc2₁ (No. 36) with lattice parameters of a = 19.7351(3), b = 7.2228(2), c = 10.0285(2) Å for the sodium and a = 17.9427(2), b = 7.5184(1), c = 9.7945(1) Å for the potassium sample. The crystal structure consists of a linked MgO₆–SO₄ layered network, where the space between the layers is filled with either potassium (K⁺) or Na⁺‐2H₂O units. The potassium‐bearing structure is isostructural to K₂Co₃(OH)₂(SO₄)₃ · 2(H₂O). The sodium compound has a similar crystal structure, where the bigger potassium ion is replaced by sodium ions and twice as many water molecules. Geometry optimization of the hydrogen positions were made with an empirical energy code.     

Untersuchungen an P4O7: Ein neues Darstellungsverfahren,Strukturdaten und schwingungsspektroskopische Charakterisierung

Investigations on P₄O₇: A New Route to Synthesis, Crystal Structure Data and Characterization by Vibrational Spectroscopy Synthesis of pure P₄O₇ in one step is achieved by oxidizing P₄O₆ in a closed system and oxygen buffered atmosphere. The complete set of crystal data is reported. An assignement of the vibrational spectra (Raman and IR) based on measurements on an oriented crystal and in comparison to P₄O₆ and P₄O₁₀ is proposed.     

Zur Kenntnis der Hydrate M(HSeO3)2 · 4H2O (M = Mg,Co, Ni,Zn). Röntgenstrukturanalytische,schwingungsspektroskopische und thermoanalytische Untersuchungen

On the Hydrates M(HSeO₃)₂ · 4H₂O (M = Mg, Co, Ni, Zn) – Crystal Structures, IR, Raman, and Thermoanalytical Investigations From aqueous solutions of M(HSeO₃)₂ single crystals of Mg(HSeO₃)₂ · 4H₂O and of the hitherto unknown compounds Co(HSeO₃)₂ · 4H₂O, Ni(HSeO₃)₂ · 4H₂O and Zn(HSeO₃)₂ · 4H₂O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm³, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm³, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm³, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm³. The crystal structures consist of hexagonal packed [M(HSeO₃)₂ · 2H₂O]_n chains of [MO₄(H₂O)₂] octahedra linked by Se atoms. They contain trigonal pyramidal SeO₂OH^?ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O? H …? O distances: 265–268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H₂O)₄ tetramers by H-bonds with unusually short O? H …? O bond distances of 271–273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe₂O₅. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.     

Ein neues Oxophosphat (IV/III)-Anion – Darstellung und Kristallstruktur von Na6P4O10 · 2 H2O

A New Oxophosphate (IV/III) Anion – Preparation and Crystal Structure of Na₆P₄O₁₀ · 2 H₂O A new oxophosphate anion, P₄O₁₀^6?, was obtained by cleavage and simultaneous oxidation of the cyclo-hexaphosphate(III) anion in a solution of aqueous ammonia and ethanol. With sodium it forms a salt with the composition Na₆P₄O₁₀ · 2 H₂O. The crystal structure has been determined by single crystal X-ray diffraction (3 745 diffractometer data), the cell constants were obtained from X-ray powder data, space group P1 ; a = 6.004(1), b = 6.173(2), c = 11.496(2) Å, α = 99.26(2)°, β = 95.92(2)°, γ = 117.63(2)°, Z = 1, R = 0.044. The backbone of the anion is formed by phosphorus atoms directly bonded to each other. The coordination of each phosphorus atom is completed to four by oxygene. The resulting oxidation numbers are +III for the inner phosphorus atoms and +IV for the terminal phosphorus atoms. The site symmetry of the anion is approximately C_2h. Based on a ³¹P-NMR spectra of a solution the coupling constants of the AA ‘BB’ system were determined.     

Ein neues Lithiumhydrogensulfat,Li2(HSO4)2(H2SO4) – Synthese und Kristallstruktur

A New Lithium Hydrogen Sulfate, Li₂(HSO₄)₂(H₂SO₄) – Synthesis and Crystal Structure The title compound crystallizes in good shaped single crystals from the system lithium sulfate/sulfuric acid in the orthorhombic space group Pccn, unit cell parameters a = 17.645(4), b = 5.378(1), c = 10.667(3) Å. V = 1 012.2 ų, Z = 4, D_x = 2.009 g cm^?3. There are two types of SO₄ tetrahedra, SO₃(OH) and SO₂(OH)₂, connected via hydrogen bonds forming layers parallel to the xy-plane. The layers are linked by Li atoms, which are tetrahedral coordinated by O atoms coming two by two from neighboured layers.     

Infrarotspektroskopische und thermoanalytische Untersuchung von Trikobalt(II)-dihydroxidsulfat-dihydrat,Co3(OH)2(SO4)2 · 2H2O

The infrared spectra between 600 and 4000 cm^?1 of Co₃(OH)₂(SO₄)₂ · 2H₂O, Co₃(OH)₂(SO₄)₂, and Co₃(OD)₂(SO₄)₂ · 2D₂O are reported and discussed. The spectra are mainly examined in relation to the binding state of the water molecules. The results are in good agreement with the previously described crystal structure studies. Thermogravimetry, differential thermal analysis and X-ray diffraction methods were used to investigate the unusual thermal decomposition behaviour of Co₃(OH)₂(SO₄)₂ · 2H₂O. The kinetics of the dehydration reaction are discussed.     

SrCl2 · 1/2 H2O und SrCl2 · H2O Röntgenographische,thermoanalytische, Raman- und IR-spektroskopische Untersuchungen

SrCI₂ · 1/2 H₂O and SrCl₂ · H₂O. X-ray, Thermalanalytical, Raman, and I. R. Data The formation of the new compound SrCI₂ · 1/2 H₂O was detected with help of high-temperature X-ray and high-temperature Raman measurements. Strontium chloride hemihydrate was prepared by dehydration of the higher hydrates in a water-vapour atmosphere of 1 bar at 165 °C. The Course of dehydration of SrCI₂ · 6 H₂O, and SrCI₂ · 2 H₂O is discussed. X-ray, i.r.-and Raman data of SrCI₂ · 1/2 H₂O and SrCl₂ · H₂O are reported. SrCI₂ · H₂O crystallizes ortho-rhombic in the BaCI₂ · H₂O type (space group Pnma) with a = 1088.1(1), b = 416.2(1), and c = 886.4(1) pm. The water modes of the hydrates as well as the force constants and bond energies of the hydrogen bridges are discussed.     

Kristallstruktur und schwingungsspektrometrische Daten von cis-Na2[Pd(SO3)2en] · 4 H2O

Crystal Structure and Data from Vibrational Spectra of cis-Na₂[Pd(SO₃)₂en] · 4 H₂O The compound cis-Na₂[Pd(SO₃)₂en] · 4 H₂O (en = 1,2-diaminoethane) crystallizes in the orthorhombic space group Pnma with a = 623.7(2), = 1070.9(10), c = 1989.5(30) pm and Z = 4. In the [Pd(SO₃)₂en]^2? anions the trans-influence of the sulfite ligands manifests itself in long Pd? N bonds with short Pd? S distances. A set of Na⁺ ions is present in face-sharing octahedra Na(OH₂)₆⁺, forming rods [Na(OH₂)_6/2]⁺ parallel to [100]. A second set of Na⁺ ions is surrounded by two H₂O molecules and four O atoms from SO₃ ligands of two anions to form likewise octahedra with face-sharing, yielding rods [Na(OH₂)_2/2{(OSO₂)₂Pd en}_2/2]^? parallel to [100]. Comparatively low v(Pd? N)-frequencies reveal the trans-influence of the sulfite ligands also in the vibrational spectra.     

Darstellung und Eigenschaften von Na2CuII (SO4)2 · 6 H2O

Preparation and Properties of Na₂Cu^II (SO₄)₂ · 6 H₂O The preparation of the complex compound of Na₂Cu(SO₄)₂ · 6 H₂O is described. Its structure and properties were investigated using spectral methods (u.v.-vis., i.r., n.m.r.), by means of X-ray powder diffraction, and by thermal methods. On the basis of experimental results it is suggested that another member of the Tutton salts series has been prepared, appearring isostructural with them and showing the less distorted coordination polyhedron of [Cu(H₂O)₆]²⁺ from them. On its dehydration oxygen atoms from the sulphate groups enter the coordination sphere of Cu^II and the symmetry of SO₄^2? becomes lower. The experimental results indicate that Na₂Cu(SO₄)₂ · 6 H₂O as also Na₂Cu(SO₄)₂ as likewise Na₂Cu(SO₄)₂ · 2 H₂O are monoclinic.     

Zur Darstellung und Kristallstruktur von CrSO4 · 3 H2O

Preparation and Crystal Structure of CrSO₄ · 3 H₂O Evaporating a solution of Cr²⁺ in dilute sulphuric acid at 70°C light blue crystals of CrSO₄ · 3 H₂O were grown. Its x-ray powder diffraction pattern is quite similar to that of CuSO₄ · 3 H₂O. The crystal structure refinement of CrSO₄ · 3 H₂O (space group Ce, a = 5.7056(8) Å, b = 13.211(2) Å, c = 7.485(1) Å, β = 96.73(1)°, Z = 4) from single crystal data, using the parameters of the copper compound as starting values, results in a final R-value of R = 3.8%. The surrounding of the Cr²⁺ ion can be described as a strongly elongated octahedron. The basal plane of the CrO₆-octahedron consists of three hydrate oxygen atoms and one sulphate oxygen atom. The two more distant axial oxygen atoms also belong to sulphate groups. Thus they are forming chains of alterning CrO₆-octahedra and SO₄-tetrahedra along [110] and [1–10] linked via common corners. These chains are connected via sulphate groups and by bridging hydrogen bonds to a 3-dimensional network.     

Synthese und Kristallstruktur von Pb2P4O12 · 3 H2O

Synthesis and Crystal Structure Determination of Pb₂P₄O₁₂ · 3 H₂O Pb₂P₄O₁₂ · 3 H₂O precipitates at mixing aqueous solutions of Pb(NO₃)₂ and Na₄P₄O₁₂ (25°C). Crystal growth was achieved by applying gel-techniques (Agar-Agar-gel). The crystal structure (P1 , a = 786.4(3), b = 914.4(3), c = 1021.6(3) pm, α = 97.42(2)°, β = 100.63(2)°, γ = 114.92(2)°; Z = 2; 4160 unique diffractometer data, R = 0.05) contains cyclo-tetraphosphate anions with point symmetry D_2d. Lead is coordinated by eight oxygen, the polyhedra deriving from a square antiprism.     

Die Kristallstruktur des SrHg(SCN)4 · 3 H2O

Crystal Structure of SrHg(SCN)₄ · 3 H₂O SrHg(SCN)₄ · 3 H₂O is orthorhombic, space group Pcca, with a = 19.476(7), b = 8.150(1), c = 8.991(3) Å, V = 1427.1 ų, Z = 4, d_c = 2.67 g · cm^?3, μ(AgKα) = 77.95 cm^?1. The salt consists of nearly tetrahedral Hg(SCN)₄ groups, Sr has a tricapped trigonal prismatic coordination: four N and five O atoms. The thiocyanate groups form end-to-end bridges and connect the Hg and Sr coordination polyhedra.     

Kristallstrukturen des Sr(BrO3)2 · H2O,Ba(BrO3)2 · H2O,Ba(IO3)2 · H2O,Pb(CIO3)2 · H2O und Pb(BrO3)2 · H2O

Crystal Structure of Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O The crystall structures of the isostructural halates Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O were determined using X-ray single crystal data (monoclinic space group C2/c? C, Z = 4), The mean bond lengths and bond angles of the halate ions in the Ba(ClO₃)₂ · 1 H₂O-type compounds, which correspond to those of other halates, are Cl? O, 149.0, Br? O, 165.9, I? O, 180.2 pm, ClO₃^?, 106.4, BrO₃^?, 104.0, and IO₃^?, 99.6°. The structure data obtained are discussed in terms of possible orientational disorder of the water molecules, strengths of the hydrogen bonds, influence of the lead ions on the structure, and site group distortion of the halate ions.     

Zur Darstellung und Kristallstruktur der Thiotellurite BaTeS3 · 2 H2O und (NH4)2TeS3

Preparation and Crystal Structure of the Thiotellurites BaTeS₃·2H₂O and (NH₄)₂TeS₃ The new compounds BaTeS₃ · 2 H₂O and (NH₄)₂TeS₃ have been prepared and their structures determined. According to these the anion of the trithiotelluric acid in these compounds represents a distorted trigonal TeS?pyramid. The Te? S-distances are 2.34–2.36 Å. Crystallographic data see ?Inhaltsübersicht”?.     

Ein neues ternäres Rubidium-Eisen Oxid Darstellung von Rb6Fe2O6

A New Rubidium-Iron Ternary Oxide. Preparation of Rb₆Fe₂O₆ Dark red crystals, formed by the heating of mixtures of rubidium and iron oxides at 773 K, were identified as the new ternary oxide Rb₆Fe₂O₆ by means of chemical analysis and X-ray powder diffraction analysis. X-ray powder diffraction data and free energy of formation data are presented, the latter having been determined by equilibrium oxygen potential measurements in liquid rubidium using a Harwell electrochemical oxygen meter.     

Die Kristallstruktur von Trikobalt(II)-dihydroxidsulfat-dihydrat,Co3(OH)2(SO4)2 · 2 H2O

Tricobalt (II)-dihydroxidesulfate-dihydrate, Co₃(OH)₂(SO₄)₂ · 2H₂O, is orthorhombic: a = 7.21, b = 9.77, c = 12.86 Å, V = 905.9 ų, space group D-Pbcm with four formula units per cell. The atomic positions have been determined by threedimensional Patterson and Fourier synthesis and full-matrix least-squares refinement of single crystal X-ray diffraction data. The structure shows infinite chains [001] of Co? O octahedra sharing one edge with each other. These chains are linked together by alternating SO₄ tetrahedra and additional Co? O octahedra, thus giving rise to a three-dimensional network of polyhedra. There is no similarity to the well known layer structures of most hydroxide salts of divalent metals. The SO₄ tetrahedra are regular while the Co? O octahedra show considerable distortion. The water molecule is coordinated to one Co atom and bonded to sulfate oxygen by two weak hydrogen bridges.     

Kristallstruktur von Na5P3O10 · 6 H2O

Crystal Structure of Na₅P₃O₁₀ · 6 H₂O Na₅P₃O₁₀ · 6 H₂O crystallizes triclinic in P1 with a = 1 037.0(2), b = 984.8(4), c = 761.5(3) pm; α = 92.24(7)°, β = 94.55(9), γ = 90.87(6)°; Z = 2. The structure has been determined from fourcycle diffractometer data (2 089 independent reflections, R = 0.053). All hydrogen positions have been taken from a weighted difference-fourier-syntheses. Na₅P₃O₁₀ · 6 H₂O forms colorless, plate-like crystals, which are twinned systematically parallel (001) and can be divided mechanically into single-crystalline portions.     

Sodium magnesium sulfate decahydrate,Na2Mg(SO4)2·10H2O,a new sulfate salt

The structure of synthetic disodium magnesium disulfate decahydrate at 180 K consists of alternating layers of water‐coordinated [Mg(H₂O)₆]²⁺ octahedra and [Na₂(SO₄)₂(H₂O)₄]²⁻ sheets, parallel to [100]. The [Mg(H₂O)₆]²⁺ octahedra are joined to one another by a single hydrogen bond, the other hydrogen bonds being involved in inter‐layer linkage. The Mg²⁺ cation occupies a crystallographic inversion centre. The sodium–sulfate sheets consist of chains of water‐sharing [Na(H₂O)₆]⁺ octahedra along b, which are then connected by sulfate tetrahedra through corner‐sharing. The associated hydrogen bonds are the result of water–sulfate interactions within the sheets themselves. This is believed to be the first structure of a mixed monovalent/divalent cation sulfate decahydrate salt.     

Mg2Na2V10O28·20H2O and Mg3V10O28·28H2O

The crystal structures of dimagnesium disodium decavanadate icosahydrate, Mg₂Na₂V₁₀O₂₈·20H₂O, (I), and trimagnesium decavanadate octacosahydrate, Mg₃V₁₀O₂₈·28H₂O, (II), have been determined by single‐crystal X‐ray diffraction. They crystallize with monoclinic (C2/c) and triclinic () symmetry, respectively. All the Mg²⁺ cations in (I) and (II) are octahedrally coordinated by six water mol­ecules. The Na⁺ cations in (I) are coordinated by three water mol­ecules and three O atoms of the decavanadate anions, and link the latter into a three‐dimensional network. The decavanadate anions in (II) are not linked to one another.