共查询到20条相似文献,搜索用时 31 毫秒
1.
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. 相似文献
2.
Horst Schmidt Erik Hennings Wolfgang Voigt 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(1):i4-i6
The title compound, MgCl2·4H2O, was crystallized at 403 K and its structure determined at 200 K. The structure is built up from MgCl2(H2O)4 octahedra with a trans configuration. Each complex is situated on a crystallographic twofold axis, with the rotation axis aligned along one H2O—Mg—OH2 axis. They are connected by a complex network of O—H...Cl hydrogen bonds. The structure contains two‐dimensional sections that are essentially identical to those in the reported tetrahydrates of CrCl2, FeCl2, FeBr2 and CoBr2, but they are stacked in a different manner in MgCl2·4H2O compared with the transition metal structures. 相似文献
3.
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. 相似文献
4.
In the course of investigations relating to magnesia oxysulfate cement the basic magnesium salt hydrate 3Mg(OH)2 · MgSO4 · 8H2O (3–1–8 phase) was found as a metastable phase in the system Mg(OH)2‐MgSO4‐H2O at room temperature (the 5–1–2 phase is the stable phase) and was characterized by thermal analysis, Raman spectroscopy, and X‐ray powder diffraction. The complex crystal structure of the 3–1–8 phase was determined from high resolution laboratory X‐ray powder diffraction data [space group C2/c, Z = 4, a = 7.8956(1) Å, b = 9.8302(2) Å, c = 20.1769(2) Å, β = 96.2147(16)°, and V = 1556.84(4) Å3]. In the crystal structure of the 3–1–8 phase, parallel double chains of edge‐linked distorted Mg(OH2)2(OH)4 octahedra run along [–110] and [110] direction forming a pattern of crossed rods. Isolated SO4 tetrahedra and interstitial water molecules separate the stacks of parallel double chains. 相似文献
5.
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. 相似文献
6.
Uwe Kolitsch 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):m129-m133
Rubidium chromium(III) dioxalate dihydrate [diaquabis(μ‐oxalato)chromium(III)rubidium(I)], [RbCr(C2O4)2(H2O)2], (I), and dicaesium magnesium dioxalate tetrahydrate [tetraaquabis(μ‐oxalato)magnesium(II)dicaesium(I)], [Cs2Mg(C2O4)2(H2O)4], (II), have layered structures which are new among double‐metal oxalates. In (I), the Rb and Cr atoms lie on sites with imposed 2/m symmetry and the unique water molecule lies on a mirror plane; in (II), the Mg atom lies on a twofold axis. The two non‐equivalent Cr and Mg atoms both show octahedral coordination, with a mean Cr—O distance of 1.966 Å and a mean Mg—O distance of 2.066 Å. Dirubidium copper(II) dioxalate dihydrate [diaquabis(μ‐oxalato)copper(II)dirubidium(I)], [Rb2Cu(C2O4)2(H2O)2], (III), is also layered and is isotypic with the previously described K2‐ and (NH4)2CuII(C2O4)2·2H2O compounds. The two non‐equivalent Cu atoms lie on inversion centres and are both (4+2)‐coordinated. Hydrogen bonds are medium‐strong to weak in the three compounds. The oxalate groups are slightly non‐planar only in the Cs–Mg compound, (II), and are more distinctly non‐planar in the K–Cu compound, (III). 相似文献
7.
Synthesis, Crystal Structure, and Thermal Decomposition of Mg(H2O)6[B12H12] · 6 H2O By reaction of an aqueous solution of the free acid (H3O)2[B12H12] with MgCO3 and subsequent isothermic evaporation of the resulting solution to dryness, colourless, bead‐shaped single crystals of the dodecahydrate of magnesium dodecahydro closo‐dodecaborate Mg(H2O)6[B12H12] · 6 H2O (cubic, F4132; a = 1643.21(9) pm, Z = 8) emerge. The crystal structure is best described as a NaTl‐type arrangement in which the centers of gravity of the quasi‐icosahedral [B12H12]2— anions (d(B—B) = 178—180 pm, d(B—H) = 109 pm) occupy the positions of Tl— while the Mg2+ cations occupy the Na+ positions. A direct coordinative influence of the [B12H12]2— units at the Mg2+ cations is however not noticeable. The latter are octahedrally coordinated by six water molecules forming isolated hexaaqua complex cations [Mg(H2O)6]2+ (d(Mg—O) = 206 pm, 6×). In addition, six “zeolitic” water molecules are located in the crystal structure for the formation of a strong O—Hδ+···δ—O‐hydrogen bridge‐bonding system. The evidence of weak B—Hδ—···δ+H—O‐hydrogen bonds between water molecules and anionic [B12H12]2— clusters is also considered. Investigations on the dodecahydrate Mg[B12H12] · 12 H2O (≡ Mg(H2O)6[B12H12] · 6 H2O) by DTA/TG measurements showed that its dehydration takes place in two steps within a temperature range of 71 and 76 °C as well as at 202 °C, respectively. Thermal treatment eventually leads to the anhydrous magnesium dodecahydro closo‐dodecaborate Mg[B12H12]. 相似文献
8.
Horst Schmidt Bernhard Euler Wolfgang Voigt Gerhard Heide 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):i57-i59
The title compound, lithium magnesium chloride heptahydrate, LiCl·MgCl2·7H2O, was analyzed in 1988 by powder X‐ray diffraction [Emons, Brand, Pohl & Köhnke (1988). Z. Anorg. Allg. Chem. 563 , 180–184] and a monoclinic crystal lattice was determined. In the present work, the structure was solved from single‐crystal diffraction data. A trigonal structure was found, exhibiting a network structure of Mg(H2O)6 octahedra and Li(H2O)Cl3 tetrahedra connected by H...Cl hydrogen bonds. The [Li(H2O)]+ unit is coordinated by distorted edge‐connected Cl− octahedra. 相似文献
9.
In poly[[diaquaoxido[μ3‐trioxidoselenato(2−)]vanadium(IV)] hemihydrate], {[VO(SeO3)(H2O)2]·0.5H2O}n, the octahedral V(H2O)2O4 and pyramidal SeO3 building units are linked by V—O—Se bonds to generate ladder‐like chains propagating along the [010] direction. A network of O—H...O hydrogen bonds helps to consolidate the structure. The O atom of the uncoordinated water molecule lies on a crystallographic twofold axis. The title compound has a similar structure to those of the reported phases [VO(OH)(H2O)(SeO3)]4·2H2O and VO(H2O)2(HPO4)·2H2O. 相似文献
10.
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. 相似文献
11.
Crystal Structure of SrZn(OH)4 · H2O Colorless crystals of SrZn(OH)4 · H2O are obtained by electrochemical oxidation of Zn in a zinc/iron pair in an aqueous ammonia solution saturated with strontium hydroxide. The X-ray crystal structure determination was now successful including all hydrogen positions: P1 , Z = 2, a = 6.244(1) Å, b = 6.3000(8) Å, c = 7.701(1) Å, α = 90.59(1)°, β = 112.56(2)°, γ = 108.66(2)°, N(F ≥ 3σF) = 1967, N(Var.) = 84, R/Rw = 0.020/0.024. In SrZn(OH)4 · H2O Zn2+ is tetrahedrally coordinated by four OH? -ions while Sr2+ has 6 OH? and one H2O as neighbours. The polyhedra around Sr2+ are connected to chains which are linked three-dimensionally by isolated tetrahedra [Zn(OH)4]. Hydrogen bonds between H2O as donor and OH? are characterized by raman spectroscopy. 相似文献
12.
Dehydration is an important process which affects the chemical, physical and mechanical properties of materials. This article describes the thermal dehydration and decomposition of the Sorel cement phase 3Mg(OH)2 · MgCl2 · 8H2O, studied by in situ synchrotron X‐ray powder diffraction and thermal analyses. Attention is paid on the determination of the chemical composition and crystal structure of the lower hydrates, identified as the phases 3Mg(OH)2 · MgCl2 · 5.4H2O and 3Mg(OH)2 · MgCl2 · 4.6H2O. The crystal structure of 3Mg(OH)2 · MgCl2 · 4.6H2O is solved and refined by the Rietveld method and a structural model for the 3Mg(OH)2 · MgCl2 · 5.4H2O phase is given. These phases show statistical distribution of water molecules, hydroxide and chloride anions positioned as ligands on the magnesium octahedra. A structural scheme of the temperature induced transformations in the thermal range from 25 to 500 °C is presented. 相似文献
13.
N. Boudjada 《无机化学与普通化学杂志》1981,477(6):225-228
Te(OH)6 · 2Na3P3O9 · 6H2O, is hexagonal (P63/m) with a = 11,67(1), c = 12,12(1) Å, Z = 2 and Dx = 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 Dx = 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. 相似文献
14.
Crystal Structure of CaZn2(OH)6 · 2 H2O The electrochemical oxidation of zinc in a zinc/iron-pair leads in an aqueous NH3 solution of calciumhydroxide at room temperature to colourless crystals of CaZn2(OH)6 · 2 H2O. The X-ray structure determination was now successful including all hydrogen positions. P21/c, Z = 2, a = 6.372(1) Å, b = 10.940(2) Å, c = 5.749(2) Å, β = 101.94(2)° N(F ≥ 3σF) = 809, N(Var.) = 69, R/RW = 0.011/0.012 The compound CaZn2(OH)6 · 2H2O contains Zn2+ in tetrahedral coordination by OH? and Ca2+ in octahedral coordination by four OH? and two H2O. The tetrahedra around Zn2+ form corner sharing chains, three-dimensionally linked by isolated polyhedra around Ca2+. Weak hydrogen bridge bonds result between H2O as donor and OH?. 相似文献
15.
Dicarboxylate Groups as Ligands and Anions in Aquamagnesium Complexes: Crystal Structures of [Mg (C4H2O4)(H2O)4] · H2O and [Mg(H2O)6](C4HO4)2 · 2H2O ((C4H2O4)2— = Fumarate; (C4HO4)— = Hydrogenacetylenedicarboxylate) Crystals of tetraaqua(fumarato)magnesium‐hydrate ( 1 ) and hexaaquamagnesium‐bis(hydrogenacetylenedicarboxylate)‐dihydrate ( 2 ) were prepared by reacting MgCl2 with sodium fumarate and acetylenedicarboxylic acid, respectively. In 1 cis‐Mg(H2O)4 units are bridged by α, Ö‐bonded fumarate groups. The resulting zig zag chains exhibit the maximum symmetry compatible with space group symmetry C2/c. 2 consists of layers of voluminous [Mg(H2O)6]2+ cations alternating with layers of C4HO4— anions. The nearly planar anions are held together by parallel stacking and by short hydrogen bonds. Both structures contain efficient H bridging systems. 1 : Space group C2/c, Z = 4, lattice constants at 20 °C: a = 5.298(1), b = 13.178(2), c = 13.374(2)Å; ß = 94.79(2)°, R1 = 0.024. 2 : Space group P1, Z = 1, lattice constants at 20 °C: a = 5.985(1), b = 6.515(1), c = 11.129(1)Å; α = 105.24(2), ß = 91.87(3), γ = 90.92(1)°, R1 = 0.034. 相似文献
16.
Akifumi Iida Tomoji Ozeki 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):i43-i46
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. 相似文献
17.
William T. A. Harrison 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e421-e421
Hydrothermally prepared mansfieldite, AlAsO4·2H2O (aluminium arsenate dihydrate), contains a vertex‐sharing three‐dimensional network of cis‐AlO4(H2O)2 octahedra and AsO4 tetrahedra [dav(Al—O) = 1.907 (2) Å, dav(As—O) = 1.685 (2) Å and θav(Al—O—As) = 134.5 (1)°]. 相似文献
18.
Samia Yahyaoui Rached Ben Hassen Bruno Donnadieu Jean‐Claude Daran Abdelhamid Ben Salah 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):i109-i111
The title compound, namely octaaquaytterbium(III) aquanonachlorotricadmate(II) hexahydrate, [Yb(H2O)8][Cd3Cl9(H2O)]·6H2O, was prepared by evaporation at 278 K from an aqueous solution of the ternary system YbCl3–CdCl2–H2O and was characterized by elemental chemical analysis and by X‐ray powder and single‐crystal diffraction studies. The crystal structure can be viewed as being built from layers of double chains of CdCl6 and CdCl5(H2O) octahedra separated by antiprismatic [Yb(H2O)8]3+ cations. The stabilization of the structure is ensured by O—H⋯O and O—H⋯Cl hydrogen bonds. A comparison with the structures of SrCd2Cl6·8H2O and CeCd4Cl11·13H2O is presented. 相似文献
19.
Dirk Hinz‐Hübner 《无机化学与普通化学杂志》2002,628(8):1811-1814
An Anionic Oxohydroxo Complex with Bismuth(III): Na6[Bi2O2(OH)6](OH)2 · 4H2O Colourless, plate‐like, air sensitive crystals of Na6[Bi2O2(OH)6](OH)2 · 4H2O are obtained by reaction of Bi2O3 or Bi(NO3)3 · 5H2O in conc. NaOH (58 wt %) at 200 °C followed by slow cooling to room temperature. The crystal structure (triclinic, P 1¯, a = 684.0(2), b = 759.8(2), c = 822.7(2) pm, α = 92.45(3)°, ß = 90.40(3)°, γ = 115.60(2)°, Z = 1, R1, wR2 (all data), 0, 042, 0, 076) contains dimeric, anionic complexes [Bi2O2(OH)6]4— with bismuth in an ψ1‐octahedral coordination of two oxo‐ and three hydroxo‐ligands. The thermal decomposition was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In the final of three steps the decomposition product is Na3BiO3. 相似文献
20.
Hydrothermal investigations in the system MgO/B2O3/P2O5(/H2O) yielded two new magnesium borophosphates, Mg2(H2O)[BP3O9(OH)4] and Mg(H2O)2[B2P2O8(OH)2]·H2O. The crystal structures were solved by means of single crystal X‐ray diffraction. While the acentric crystal structure of Mg2(H2O)[BP3O9(OH)4] (orthorhombic, P212121 (No. 19), a = 709.44(5) pm, b = 859.70(4) pm, c = 1635.1(1) pm, V = 997.3(3) × 106 pm3, Z = 4) contains 1D infinite chains of magnesium coordination octahedra interconnected by a borophosphate tetramer, Mg(H2O)2[B2P2O8(OH)2]·H2O (monoclinic, P21/c (No. 14), a = 776.04(5) pm, b = 1464.26(9) pm, c = 824.10(4) pm, β = 90.25(1)°, V = 936.44(9) × 106 pm3,Z = 4) represents the first layered borophosphate with 63 net topology. The structures are discussed and classified in terms of structural systematics. 相似文献