Zur Koordination des Aluminiums in den Calciumaluminathydraten 2 CaO · Al2O3 · 8 H2O und CaO · Al2O3 · 10 H2O

On the Coordination of Al in the Calcium Aluminate Hydrates 2 CaO · Al₂O₃ · 8 H₂O and CaO · Al₂O₃ · 10 H₂O By investigations with high-resolution ²⁷Al-NMR in solids it is shown that in the compound 2 CaO · Al₂O₃ · 8 H₂O the Al merely exist in octahedral coordination. According to this and considering its structural relationship with 4 CaO · Al₂O₃ · 19 H₂O the dicalcium aluminate hydrate is proposed to be formulated as [Ca₂Al(OH)₆][Al(OH)₃ (H₂O)₃]OH. Likewise for the compound CaO · Al₂O₃ · 10 H₂O the octahedral coordination of the Al is proved by ²⁷Al-NMR. This result corresponds with literature according to which a constitution as cyclohexaaluminate Ca₃[Al₆(OH)₂₄] · 18 H₂O is proposed.     

Erdalkali-Fluoromanganate(III): BaMnF5 · H2O und SrMnF5 · H2O

Alkaline Earth Fluoromanganates(III): BaMnF₅ · H₂O and SrMnF₅ · H₂O Solid BaF₂ or SrF₂ forms with solutions of Mn³⁺ in aqueous hydrofluoric acid precipitates of hitherto unknown BaMnF₅ · H₂ and SrMnF₅ · H₂O respectively. X-ray structure determination on single crystals of both isotypic compounds (space group P2₁/m, Z = 2; BaMnF₅ · H₂O: a = 537.0(3), b = 817.2(2), c = 628.0(4) pm β = 111.17(5)°, R_w = 0.035 for 1403 reflections; SrMnF₅ · H₂O: a = 510.8(1), b = 792.0(2), c = 610.6(1) pm, β = 110.24(1)° R_w = 0.068 for 539 reflections) reveal pure [MnF₆]^3? octahedra connected with each other to infinite chains by sharing trans corners. The H₂O molecules are coordinated to the alkaline earth ions only and form weak O? H…F hydrogen bonds. The pronounced weakening of the Mn? F bonds within the chain direction (Mn? F 2X 212.7(1)/210.8(5) pm, 2X 183.8(3)/181.8(9) pm, 2X 186.9(2)/187.2(8) pm) may be due by halves to the Jahn-Teller-effect as can be deduced by bond valence calculations.     

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.     

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.     

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.     

Die Kristallstrukturen von K8Ta6O19 · 16H2O und K7NaTa6O19 · 14H2O

The Crystal Structures of K₈Ta₆O₁₉ · 16H₂O and K₇NaTa₆O₁₉ · 14H₂O By alkaline digestion of Ta₂O₅ with p.a. KOH transparent single crystals of the composition K₈Ta₆O₁₉ · 16H₂O are formed. When technical grade KOH is used, the same kind of synthesis yields crystals of the composition K₇NaTa₆O₁₉ · 14H₂O. The latter compound has been given the formula K₈Ta₆O₁₉ · 14H₂O until now. In both cases the isopolyoxoanion [Ta₆O₁₉]⁸ consists of six TaO₆-octahedra connected by edge sharing. This means that the heavy atom partial structure found by Lindquist et al. is confirmed. Additionally the complete structures including the atomic positions of the oxygen atoms of the polyanions as well as those of the cations and crystal water molecules (without hydrogen positions) are determined.     

Einkristallzüchtung und Röntgenstrukturanalyse von CoSO4 · Pyrazin · 6 H2O (I) und (CoSO4)2 · Pyrazin · 12 H2O (II)

Crystal Growth and Structure of CoSO₄ · Pyrazine · 6 H₂O (I) and (CoSO₄)₂ · Pyrazine · 12 H₂O (II) Single crystals of μ-pyrazino-bis[pentaquacobalt(II)]-sulfate-dihydrate CoSO₄(pz) · 6 H₂O and Tetraqua-μ-pyrazino-cobalt(II)sulfate-dihydrate (CoSO₄)₂(pz) · 12 H₂O were grown by using gel methods and investigated by X-ray analysis. CoSO₄(pz) · 6 H₂O (I) shows monoclinic symmetry, space group C2/c; a = 1006.4(4) pm, b = 1026.9(4) pm, c = 1261.5(2) pm; β = 104.01(4)°; Z = 4. (CoSO₄)₂(pz) · 12 H₂O (II) shows orthorhombic symmetry, space group Pbam; a = 1262.3(4) pm, b = 1231.3(4) pm, c = 684.1(2) pm; Z = 2. CoSO₄ and Pyrazine crystallize in a polymeric (I) as well as in a dimeric (II) compound. In the polymeric compound the molecules are bonded by pyrazine to form alternating linear chains. The dimer is a dinuclear complex with a bridging pyrazine molecule.     

Zu Herstellung und Konstitution der Verbindung 3 CaO · 3 GeO2 · H2O

On the Preparation and Constitution of the Compound 3 CaO · 3 GeO₂ · H₂O In the temperature range from 100–∽450°C it is possible to prepare under hydrothermal conditions from equimolar mixtures of CaO and GeO₂ the compound 3 CaGeO₃ · H₂O. By n.m.r. measurements of the solid compound it is shown, that there are only OH groups and no molecular water. It seems to be probable that this compound is a trigermanate of the formula Ca₃H₂ [Ge₃O₁₀].     

Zur Thermischen Zersetzung von CaOP3F · 2 H2O

On the Thermal Decomposition of CaPO₃F · 2H₂O . The thermal decomposition of CaPO₃F · 2H₂O was investigated by thermogravimetry under inert conditions. A parallel mass spectrometric analysis of gases produced is made. Using an effusion cell a quasi equilibrium evaporation in the nearness of the ion source of the spectrometer is achieved. The results are comparable with the thermogravimetric analysis under normal pressure. During first state of thermal decomposition one mole H₂O is lost. Then the further course is determined by release of HF and POF₃. The several steps of decomposition leading to α-Ca₂P₂O₇ at temperatures above 360° C are discussed.     

Zur Kenntnis der Phase BaO · Al2O3 · 7 H2O

On the Compound BaO · Al₂O₃ · 7 H₂O On the basis of investigations using ²⁷Al, ¹H NMR, IR and thermoanalytical methods for the compound BaO · Al₂O₃ · 7 H₂O a constitution as Ba_n[Al₂(OH)₈]_n · 3n H₂O with condensed AlO₆ groups, sharing edges, is proposed. Relations between the Ba/Al ratio and the constitution of anions of barium aluminate hydrates are discussed.     

Kristallstrukturen des Sr(OH)2 · H2O,Ba(OH)2 · H2O (o.-rh. und mon.) und Ba(OH)2 · 3 H2O

Crystal Structures of Sr(OH)₂ · H₂O, Ba(OH)₂ · H₂O (o.-rh. and mon.), and Ba(OH)₂ · 3 H₂O The crystal structures of Ba(OH)₂ · 3 H₂O (Pnma, Z = 4), γ-Ba(OH)₂ · H₂O (P2₁/m, Z = 2) and the isotypic Sr(OH)₂ · H₂O and β-Ba(OH)₂ · H₂O (Pmc2₁, Z = 2) were determined using X-ray single crystal data. Ba(OH)₂ · 3 H₂O and Ba(OH)₂ · H₂O mon. crystallize in hitherto unknown structure types. The structure of Ba(OH)₂ · H₂O mon. is strongly related to that of rare earth hydroxides M(OH)₃ with space group P6₃/m (super group of P2₁/m). The metal-oxygen distances are significantly shorter for OH^? ions (mean Ba—O bond lengths of all hydroxides under investigation 278.1 pm) than for H₂O molecules (289.9 pm). Corresponding to other hydrates of ionic hydroxides, the water molecules form strong hydrogen bonds to adjacent OH^? ions whereas the hydroxide are not H-bonded.     

Darstellung und Kristallstruktur von Kupfer(II)-monofluorophosphat-Dihydrat CuPO3F · 2H2O

Salts of Halogenophosphoric Acids. XVII. Preparation and Crystal Structure of Copper(II) Monofluorophosphate Dihydrate CuPO₃F · 2H₂O Copper(II) monofluorophosphate dihydrate, CuPO₃F · 2H₂O 1 was obtained by the reaction of aqueous NH₄HPO₃F and acid (NH₄)₂PO₃F solutions, respectively, using acetone or ethanol as precipitating agents. The thermal dehydration of 1 gives the water-free copper monofluorophosphate CuPO₃F ( 2 ). 1 crystallizes in the monoclinic space group P2₁/c with a = 761,44, b = 780,97, c = 921,02 pm, β = 112,94° and Z = 4.     

Hydrate schwacher und starker Basen. XI. Die Kristallstrukturen von NaOH · 3,5H2O und NaOH · 7 H2O. Eine Präzisierung

Hydrates of Weak and Strong Bases. XI. The Crystal Structures of NaOH · 3,5H₂O and NaOH · 7 H₂O. A Refinement The crystal structures of the hydrates NaOH · 3,5 H₂O (space group P2₁/c, Z = 8 formula units per unit cell; lattice parameters: a = 6.481, b = 12.460, c = 11.681 Å, β = 104.12° at ?100°C) and NaOH · 7 H₂O (P2₁/c, Z = 4; a = 7.344, b = 16.356, c = 6.897 Å, β = 92.91° at ?150°C) have been redetermined using MoKα diffractometer data. The obtained refinement of the structures, including the localization also of the H atoms for the first time, has led to new findings with respect to the H bonds. In particular, in both hydrates there is one such interaction of the rare type OH^? …? OH₂, from an OH^? ion to an H₂O molecule, i. e. with the OH^? ion as the proton donor.     

New Fluoromanganate(III) Hydrates: Mn3F8 · 12H2O and AgMnF4 · 4H2O

Single crystals of fluoride hydrates Mn₃F₈ · 12 H₂O and AgMnF₄ · 4 H₂O have been prepared and characterized by X-ray methods. Mn₃F₈ · 12 H₂O crystallizes in the space group P1 (a = 623.0(3), b = 896.7(4), c = 931.8(4) pm, α = 110.07(2)°, β = 103.18(2)°, γ = 107.54(2)°, Z = 1); AgMnF₄ · 4 H₂O crystallizes in the space group P2₁/m (a = 700.9(2), b = 726.1(1), c = 749.4(3) pm, β = 107.17(3)°, Z = 2). Both structures contain Jahn-Teller-distorted [Mn(H₂O)₂F₄]^? anions as well as crystal water molecules and exhibit a complex hydrogen bond network between anions and cations, i. e. [Mn(H₂O)₆]²⁺ for the first and a polymeric [Ag(H₂O)₂]^? cation for the second compound.     

Hydrate schwacher und starker Basen. VII. Zum System Caesiumhydroxid-Wasser: Die Kristallstrukturen von CsOH · 2H2O und CsOH · 3H2O

Hydrates of Weak and Strong Bases. VII. Concerning the System Cesium Hydroxide—Water: The Crystal Structures of CsOH · 2H₂O and CsOH · 3H₂O In the context of structural studies of hydrates of the alkali metal hydroxide the crystal structure of CsOH · 2H₂O and CsOH · 3H₂O have been determined for the first time. The diffractometer data, obtained at -150 · C,made it possible to locate and refine also all the H-atoms. The dihydrate was found to probably form only one phase, melting incongruently at 2,5 · C. It is orthorhombic with space group Pca2₁ and Z = 8 formula units per unit cell. The lattice constants are a = 13.238, b = 6.747 and c = 9.121 A. With 1870 independent observed reflection a final R value of 0.013 was obtained. The trihydrate, melting congruently et -5.5 ·C, is monoclinic with space group P2₁/n,Z = 4 and lattice constants a = 8.637, b = 5.984, c = 10.061 Å and ß = 96.57 ·. With 2098 independent observed reflection the final R is 0.026. In both hydrate structures there are no simple characteristic coordination polyhedra for the cations; in each case it is rather the hydrogen-bonded and fully ordered anionic water structure which shows up as the determining building principle. Both these water structures are altogether three-dimensional, but primarily contain layers. The anionic layers are formed by condensation of small and medium rings, namely four-, five- and seven-membered rings in CsOH · 2H₂O and four-, five- and six membered ones in CsOH · 3H₂O. They are linked together by one set each of extra H₂O molecules between the layers as well as by the Cs⁺ ions.     

Alkalimolybdotellurate: Darstellung und Kristallstruktur von Rb6[TeMo6O24] · 10H2O und Rb6[TeMo6O24] · Te(OH)6 · 6H2O

Alkaline Molybdotellurates: Preparation and Crystal Structures of Rb₆[TeMo₆O₂₄] · 10H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6H₂O Single crystals of Rb₆[TeMo₆O₂₄] · 10 H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O, respectively, were grown from aqueous solution. Rb₆[TeMo₆O₂₄] · 10 H₂O possesses the space group P1 . The lattice dimensions are a = 963.40(13), b = 972.56(12), c = 1 056.18(13) pm, α = 97.556(10), β = 113.445(9), γ = 102.075(10)°; Z = 1, 2 860 reflections, 215 parameters refined, R_g = 0.0257. The centrosymmetrical [TeMo₆O₂₄]^6? anions are stacked parallel to [010]. Rb(2) is coordinated with one exception by water molecules only. Folded chains consisting of [TeMo₆O₂₄]^6? anions and Rb(2) coordination polyhedra which are linked to pairs represent the prominent structural feature. Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O crystallizes monoclinically in the space group C2/c with a = 1 886.4(3), b = 1 000.9(1), c = 2 126.5(3) pm, and β = 115.90(1)°; Z = 4, 3 206 reflections, 240 parameters refined, R_g = 0.0333. It is isostructural in high extent with (NH₄)₆[TeMo₆O₂₄] · Te(OH)₆ · 7 H₂O. Hydrogen bonds between Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions establish infinite strands. The [TeMo₆O₂₄]^6? anions gather around Te(OH)₆ providing channel-like voids extending parallel to [001].     

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.     

Zur Struktur von zwei Hydraten des Natriumphenolats: C6H5ONa · H2O und C6H5ONa · 3 H2O

The Structures of two Hydrates of Sodium Phenoxide: C₆H₅ONa · H₂O and C₆H₅ONa · 3 H₂O In the monohydrate of sodium phenoxide sodium is coordinated by 4 oxygen atoms having an average distance Na? O of about 2.631 Å being arranged in form of a distorted tetrahedron. The oxygen atoms of water and phenoxid serve as bridging ligands. Hence, the structure can be considered as a network with a general formula [Na^[4]O]. Moreover, the oxygen atoms are linked via hydrogen bonding. In the trihydrate of sodium phenoxide sodium is surrounded with 5 oxygen atoms with an average distance of 2.39 Å forming a tetragonal pyramide. The oxygen of the phenoxide, however, does not participate in the coordination of the sodium ion. The coordination polyhedrons are connected by sharing edges and verteces. The resulting layer can be described by the general formula [Na^[5]O₂^[2]O^[2]O^[1]]. Via hydrogen bonding the phenoxide ions are attached to this layer.     

Kristallstrukturbestimmung von NaHC2O4 · H2O

NaHC₂O₄ · H₂O crystallizes in space group P 1 with a₀ = 6,51, b₀ = 6,66, c₀ = 5,70 Å, α₀ = 95,0°, β₀ = 109,8°, γ₀ = 74,9° and Z = 2. The structure was solved by direct methods. The refinement was carried out with 679 reflections to R₁ = 7,7%. The angle between the O? C? O planes is 12,6°.     

K2TiSi3O9·H2O

Single crystals of dipotassium titanium trisilicate hydrate were synthesized and the crystal structure was refined using data from single‐crystal X‐ray diffraction. The structure is a three‐dimensional mixed framework and contains channels formed by six‐ and eight‐membered rings. K⁺ ions and water mol­ecules are located in the channels.