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 Kenntnis der Hydrate des Typs MX2 · 1 H2O mit M = Sr,Ba und X = Cl,Br, I. Kristallstrukturen des Strontiumchlorid-Monohydrats,SrCl2 · 1 H2O,und des Strontiumbromid-Monohydrats,SrBr2 · 1 H2O

On Hydrates of the Type MX₂ · 1 H₂O with M = Sr, Ba and X = Cl, Br, I. Crystal Structures of Strontium Chloride Monohydrate, SrCl₂ · 1 H₂O, and Strontium Bromide Monohydrate, SrBr₂ · 1 H₂O The structures of SrCl₂ · 1 H₂O, orthorhombic, Pnma, a = 1088.1(1), b = 416.2(1), c = 886.4(1) pm, Z = 4, d_c = 2.92 Mg m^?3, R = 0.052 for 755 reflections, and of SrBr₂ · 1 H₂O, orthorhombic, Pnma, a = 1146.4(1), b = 429,5(1), c = 922.9(1) pm, Z = 4, d_c = 3.88 Mg m^?3, R = 0.056 for 762 reflections have been determined from a Patterson synthesis and refined by Fourier and Least Squares methods. The structure consists of [SrX₂ = H₂O]_n-layers normal to [100] and Sr? H₂O? Sr? H₂O-chains parallel [010]. The Sr? O distances are 265.1(3) pm, SrCl₂ · 1 H₂O, and 265.9(4) pm, SrBr₂ · 1 H₂O. The shortest Sr? Cl and Sr? Br distances (298.9(1) and 315.3(1) pm) are within the layers. The environment of oxygen and strontium is a distorted tricapped trigonal prism. The orientation of the water molecules has been determined from vibrational spectroscopic measurements. The hydrogen atoms H₁ and H₂ form bifurcated hydrogen bonds of different strength to neighbouring halide ions. The corresponding O···X distances are 331.9(4) and 320.2(4) pm, SrCl₂ · 1 H₂O, and 340.8(4) and 333.8(4) pm, SrBr₂ · 1 H₂O. The other O? X distances are between 310.3(5) and 323.7(5) pm, SrCl₂ · 1 H₂O, and 323.5(5) and 333.2(6) pm, SrBr₂ · 1 H₂O.     

Darstellung und Kristallstrukturen von tBu‐substituierten Disiloxanen des Typus tBu2SiX‐O‐SiYtBu2 (X = Y = OH,Br; X = OH,Y = H) und den Addukten tBu3SiOH·(HO3SCF3)0.5·H2O und tBu3SiOLi·(LiO3SCF3)2·(H2O)2

Syntheses and Crystal Structures of tBu‐substituted Disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = OH, Br; X = OH, Y = H) and of the Adducts tBu₃SiOH·(HO₃SCF₃)_0.5·H₂O and tBu₃SiOLi·(LiO₃SCF₃)₂·(H₂O)₂ The disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = H, OH) are accessible from the reaction of CF₃SO₂Cl with tBu₂SiHOH or tBu₂Si(OH)₂. By this reaction the disiloxane tBu₂SiH‐O‐SiHtBu₂ is formed together with tBu₂SiH‐O‐SiOHtBu₂. The disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = Cl, Br) can be synthesized almost quantitatively from tBu₂SiH‐O‐SiHtBu₂ with Cl₂ and Br₂ in CH₂Cl₂. The structures of the disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = H, Y = OH; X = Y = OH, Br) show almost linear Si‐O‐Si units with short Si‐O bonds. Single crystals of the adducts tBu₃SiOH·(HO₃SCF₃)_0.5·H₂O and tBu₃SiOLi·(LiO₃SCF₃)₂·(H₂O)₂ have been obtained from the reaction of tBu₃SiOH with CF₃SO₃H and of tBu₃SiO₃SCF₃ with LiOH. According to the result of the X‐ray structural analysis (hexagonal, P‐62c), tBu₃SiOLi · (LiO₃SCF₃)₂·(H₂O)₂ features the ion pair [(tBu₃SiOLi)₂(LiO₃SCF₃)₃(H₂O)₃Li]⁺ [CF₃SO₃]^?. The central framework of the cation forms a trigonal Li₆ prism.     

Die Kristallstrukturen von Tl2AgI3 und NaAgI2 · 3 H2O

Crystal Structure Investigations of Tl₂AgI₃ und NaAgI₂ · 3 H₂O Tl₂AgI₃ was synthesized by the reaction of TlI with AgI in aqueous HI (25%) in a pressure vessel. The compound crystallizes in the rhombohedral space group R3 ; a = 1044,3(2); c = 1993,5(3)pm; Z = 9. The crystal structure contains trinuclear anions [Ag₃I₈]^5? and [ITl₆]⁵⁺ octahedra. The anions are composed of two AgI₄-tetrahedra which are connected to an AgI₆ octahedron via common faces. Single crystals of NaAgI₂ · 3 H₂O were formed by reaction of NaI with AgI in aqueous solution. The compound crystallizes in the orthorhombic space group Pbca with lattice parameters a = 711,2(2); b = 939,8(3); c = 2462,2(4) pm; Z = 8. The crystal structure is built up by polymeric layers [AgI_3/3I_½^1/2?] of corner sharing AgI₄ tetrahedra (GaOCl type) and [Na(H₂O)_4/2(H₂O)I_½^1/2+] octahedra chains.     

Zur Kenntnis des Bariumhexahydroxoplatinats BaPt(OH)6 · H2O

On Barium Hexahydroxoplatinate BaPt(OH)₆ · H₂O The crystal structure of BaPt(OH)₆ · H₂O, monoclinic, space group P2₁/m, a = 628.4, b = 624.6, c = 857.4 pm, β = 108.19°, Z = 2, contains octahedral Pt(OH)₆ groups and ninefold-coordinated barium. The water molecules are not coordinated to metal atoms but connected with Pt(OH)₆ groups only by very weak hydrogen bonds with oxygen-oxygen distances of 292—296 pm. The compound is dehydrated readily when dried gently. This explains contradictory evidence concerning its water content.     

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.     

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.     

Preparation and crystal data for two trimetaphosphate tellurates: Te(OH)6 · 2Na3P3O9 · 6H2O and Te(OH)6 · K3P3O9 · 2H2O

Te(OH)₆ · 2Na₃P₃O₉ · 6H₂O, is hexagonal (P6₃/m) with a = 11,67(1), c = 12,12(1) Å, Z = 2 and D_x = 2,225 g/cm³. Te(OH)₆ · K₃P₃O₉ · 2H₂O, is monoklin (P2₁/c) with a = 19,61(5), b = 7,456(1), c = 14,84(6) Å, = 108,01(4), Z = 4 and D_x = 2,506 g/cm³. Both compounds are the first examples of phosphate tellurates in which the anion phosphate is condensed to the ring anion P₃O₉. As in phosphate tellurates already described the phosphate groups are independent of the TeO₆ octahedra.     

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.     

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.     

Die Kristallstruktur des Natriumoxohydroxoaluminathydrates Na2[Al2O3(OH)2] · 1,5 H2O

The Crystal Structure of the Sodium Oxohydroxoaluminate Hydrate Na₂[Al₂O₃(OH)₂] · 1.5 H₂O The crystal structure of the sodium oxohydroxoaluminate hydrate Na₂[Al₂O₃(OH)₂] ·s 1.5 H₂O (up to now described as Na₂O · Al₂O₃ · 2.5 H₂O and Na₂O · Al₂O₃ · 3 H₂O, respectively) was solved. The X-ray single crystal diffraction analysis (tetragonal, space group P-42₁m, a = 10.522(1) Å, c = 5.330(1) Å, Z = 4) results in a polymeric layered structure, consisting of AlO_3/2(OH) tetrahedral groups. Between these layers the Na⁺ ions are situated, which form tetrameric groups of face-linked NaO₆ octahedra. The involved O^2? ions are due to Al? O? Al bridges, Al? OH groups and water of crystallization. ²⁷Al and ²³Na MAS NMR investigations confirm the crystal structure analysis. The relations between the crystallization behaviour of the compound and the constitution of the aluminate anions in the corresponding sodium aluminate solution and in the solid, respectively, are discussed.     

ChemInform Abstract: 2Mg(OH)2·MgCl2·2H2O and 2Mg(OH)2·MgCl2·4H2O,Two High Temperature Phases of the Magnesia Cement System.

The title materials exist as stable phases in the MgO—MgCl₂—H₂O system at 120 °C.     

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.     

Kristallstruktur von Cadmium-Kupfer-Hydroxidnitrat,CdCu3 (OH)6 (NO3)2·H2O

The crystal structure of cadmium copper hydroxide nitrate, CdCu₃ (OH)₆ (NO₃)₂ · H₂O, has been determined from three dimensional single crystal X-ray data. One single elementary cell of the compound has to be of triclinic symmetry, but as either the crystal is built up from such triclinic domains grown together regularly at angles of 120 degrees, or the nitrate groups of the whole crystal are distributed statistically over three possible orientations standing at 120 degree angles respectively to each other, the structure can also be described in the hexagonal system: a = 6.522 ± 0.005 Å, c = 7.012 ± 0.006 Å, space group D – P 3 m 1, cell content one formula unit. Mixed layers (00.1) of Cu and Cd atoms are embedded between layers consisting of the OH groups and one oxygen atom per nitrate group. The nitrate groups extend with their trigonal plane nearly perpendicular to the layers (00.1) and connect them by hydrogen bridges between the remaining two oxygen atoms and OH groups of the next layer. The Cd atoms are coordinated octahedrally by six equidistant OH groups, and the Cu atoms have a strongly distorted octahedral (4 + 2) coordination with four OH groups and two nitrate oxygens. Thermogravimetric measurements allowed to distinguish the crystal water molecule from variable amounts of excess water. The hydrogen bonds between OH groups and nitrate oxygen atoms and the deformation of the nitrate groups were confirmed by infrared spectra.     

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.     

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.     

Röntgenographische und spektroskopische Untersuchungen an Ba2Ni(N3)6· 3H2O

Preparation and X-Ray Examination of Ba₂Ni(N₃)₆ · 3 H₂O Ba₂Ni(N₃)₆ · 3 H₂O has been prepared by the reaction of an aqueous solution of Ba(N₃)₂ with basic nickel azide. The crystals are green, the lattice constants are: a = 7.09 Å, b = 7.09 Å, c = 16.30 Å, α = 74.58°, β = 105.42°, γ = 97.10°, N = 2. Optical spectra point to an octahedral microsymmetry of the azide ions around nickel.     

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.     

A novel crystal polymorph of volborthite,Cu3V2O7(OH)2·2H2O

A new polymorph of volborthite [tricopper(II) divanadium(V) heptaoxide dihydroxide dihydrate], Cu₃V₂O₇(OH)₂·2H₂O, has been discovered in a single crystal prepared by hydrothermal synthesis. X‐ray analysis reveals that the monoclinic structure has the space group C2/c at room temperature, which is different from that of the previously reported C2/m structure. Both structures have Cu₃O₆(OH)₂ layers composed of edge‐sharing CuO₄(OH)₂ octahedra, with V₂O₇ pillars and water molecules between the layers. The Cu atoms occupy two and three independent crystallographic sites in the C2/m and C2/c structures, respectively, likely giving rise to different magnetic interactions between Cu^II spins in the kagome lattices embedded in the Cu₃O₆(OH)₂ layers.