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1.
The crystal structure of ferrous glycine sulfate (a ferroglycine sulfate complex with chemical formula FeSO4(C2H5NO2), a compound extensively used as an iron dietary supplement, was refined from synchrotron X‐ray powder diffraction data. The crystal structure of an (so‐far unreported) isostructural manganese analogue was also structurally detailed by a Rietveld refinement against the corresponding X‐ray powder diffraction pattern. All studied compounds crystallize in the monoclinic P21 space group, building layers of metal cations coordinated by the oxygen atoms of sulfate groups and glycine ligands. Neighboring layers are parallel packed, bonded by hydrogen bonds. The coordination polyhedra around the cations can be regarded as distorted and elongated octahedral, presumably due to severe strains present in the crystal structure of the layers.  相似文献   

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Li7MO6 (M = Bi, Ru, Os) have been synthesized by solid state reaction of Li2O with Bi2O3, or MO2 (M = Ru, Os) and characterized using powder X‐ray diffraction, differential scanning calorimetry, magnetic susceptibility (for M = Ru, Os), ionic conductivity and 6Li solid state NMR (for M = Bi) measurements. All three compounds exhibit a temperature induced triclinic – rhombohedral phase transition. Structures of the new low temperature triclinic phases have been refined by the Rietveld method from powder X‐ray data using atomic parameters of Li7TaO6 as a starting model ( Li7BiO6 : triclinic, , a = 5.5071(1), b = 6.0425(1), c = 5.5231(1) Å, α = 116.912(1), β = 120.867(1), γ = 62.234(1)°, V = 133.96(1) Å3, Z = 1, T = 230 K; Li7RuO6 : triclinic, , a = 5.3654(1), b = 5.8584(1), c = 5.3496(1) Å, α = 117.182(1), β = 119.117(1), γ = 62.632(1)°, V = 124.43(1) Å3, Z = 1, T = 295 K; Li7OsO6 : triclinic, , a = 5.3786(1), b = 5.8725(1), c = 5.3591(1) Å, α = 117.193(1), β = 119.277(1), γ = 62.700(1)°, V = 125.15(1) Å3, Z = 1, T = 295 K). Upon cooling, Li7RuO6 and Li7OsO6 undergo a magnetic transition at 12 and 13 K, respectively, from the paramagnetic to the antiferromagnetic state. The higher ionic conductivity of Li7BiO6 at T < 300 °C, as compared to Li7RuO6 and Li7OsO6, can be ascribed to the undergoing of the triclinic – rhombohedral transition at a much lower temperature. At T > 300 °C, the ionic conductivity of all three compounds increases sharply due to the melting of the lithium sublattice; for Li7RuO6 and Li7OsO6 the latter effect is superimposed by the phase transitions to the rhombohedral modifications.  相似文献   

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La8Cu7O19 was synthesized by solid state reaction of the oxides La2O3 and CuO at 1288 K in air. The crystal structure was determined by a joint Rietveld refinement of X‐ray and neutron powder diffraction data. La8Cu7O19 crystallizes in the monoclinic space group C2/c (No. 15) with the lattice parameters a = 13.8310(4)Å, b = 3.75827(9)Å, c = 34.5917(8)Å and β = 99.332(2)°. La8Cu7O19 is the n = 3 member of the homologous series La4+4nCu8+2nO14+8n. The Cu—O sub‐structure in La8Cu7O19 contains infinite ribbons, which can be described as perovskite type layers with a width of n = 3 Jahn‐Teller‐elongated octahedra, and Cu—O planes of complex geometry. DSC/TG‐measurements in different gas atmospheres show peritectic decomposition of La8Cu7O19. The anisotropic thermal expansion of the lattice parameters was investigated using synchrotron radiation. The Madelung part of lattice energy was calculated and compared with the corresponding values of other lanthanum cuprates.  相似文献   

9.
The structure of one of the first permanently porous metal phosphonates, MIL‐91(Al) was re‐determined using high resolution synchrotron powder X‐ray diffraction data. The new model is in a lower symmetry space group, with no disordered ligands in the structure, whilst remaining otherwise consistent with the reported compound. New milder synthetic conditions were also developed.  相似文献   

10.
Studies on the effects of iron and nickel incorporation into the hydrothermal synthesis of ANA zeolite were carried out. The presented work reveals that pure Fe‐Al analcime is synthesized by using starting composition with a higher iron(III) content than reported in previous publications. Furthermore, the iron(III) and nickel(II) contents play important roles in the framework of the synthesized zeolite. XRD, FT‐IR spectroscopy, diffuse reflectance UV/Vis spectroscopy, nitrogen adsorption and SEM were used to characterize the synthesized zeolites. These investigations showed that loading of iron and nickel ions in ANA zeolite changes the pore size and morphology of analcime zeolite.  相似文献   

11.
Since the discovery of symplesite mineral in the late 19th century, a number of structural studies were performed. The crystal symmetry of this mineral was debated to be either monoclinic or triclinic. Even though this debate has ended, agreeing on the triclinic symmetry, no detailed crystal structure was reported so far. In the present contribution, we report on the crystal structure of symplesite. The crystal structure was solved and refined from high‐resolution laboratory X‐ray powder diffraction data, collected on a natural sample. Symplesite is shown to be isostructural to metavivianite (and possibly to ferrostrunzite).  相似文献   

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The iron nanowires can be fabricated via the process in which sodium borohydride reduces iron salts in external magnetic field. The iron nanowires are found to be covered by passivated layers of iron oxide which prevent the oxidation of iron nanowires. In this process, the boron will include in iron nanowires. The average length and diameter of iron nanowires is around 1.2 micrometers and 60 nanometers, respectively. According to ICP results, the contents of B and Fe are about 1.98 wt% and 87.04 wt%, respectively, in iron nanowires. A wide variety of equipment is used to investigate the morphological, microchemical, and structural characteristics of the newly synthesized iron nanowires ––– e.g., XRD, FE‐SEM, HR‐TEM, VSM and XANES. XANES analysis indicates the boron in iron nanowires exists in the form of B2O3. The saturation magnetization and the coercive force of iron nanowires are 157.93 emu/g and 9.74 Oe, respectively. In‐situ images of synthesized iron nanowires during reduction process in magnetic field are observed by NSRRC transmission X‐ray microscope. Thus, this study develop a novel process to produce iron nanowires with large quantitates and can control its length and diameter by various the concentration of precursors for various applications.  相似文献   

13.
The reaction of MoBr3 and pyridine at room temperature provided single crystals of mer‐[MoX3Py3]. mer‐[MoBr3Py3] crystallizes in P21/n monoclinic space group with cell dimensions a = 9.2297(5) Å, b = 12.911(8) Å, c = 15.7022(9) Å and β = 90.479(3)°. There are four formula units in a unit cell. Mo–N distances are in the range 2.196(8)–2.214(8) Å and Mo–Br distances are 2.573(1) Å and 2.574(1) Å. Fundamental vibrational frequencies of pyridine molecules are strongly affected upon coordination in all three coordination compounds: mer‐[MoBr3Py3], mer‐[MoI3Py3] and trans,trans‐[MoBr2Py4][MoBr4Py2].  相似文献   

14.
X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer’s claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form.  相似文献   

15.
The graphite‐like yttrium hydride halides, YIHn (0.8 ? n ? 1.0), have been prepared in quantitative yields by heating either YI3, YH2 (1:2) or stoichiometric YI3, YH2, Y mixtures in sealed Ta ampoules at 900°C. A lower limit of the homogeneity range, n ≈ 2/3, has been determined from dehydrogenation experiments. All YIHn phases adopt the ZrBr‐type heavy‐atom structure. The hydrogen variation is accompanied by a change in the c lattice constant from 31.162(3) to 31.033(1) Å for n = 0.61(3) to 1.02(3). The YIHn phases reversibly react with hydrogen at 400‐600°C to form the light green transparent compound YIH2. However, increasing the reaction temperature above 700°C causes decomposition to an unidentified phase being in equilibrium with YH2 and YI3. The arrangement of the heavy atoms in YIH2 (P m1; a = 3.8579(3) Å, c = 10.997(1) Å) corresponds to a four‐layer I‐Y‐Y‐I slab with the stacking sequence (AbaB) as was found by x‐ray powder diffraction data refinement with the Rietveld method. A miscibility gap exists between YIH and YIH2. Samples YIHn (n ? 1.0) show metallic conductivity at room temperature, which changes into semiconducting behavior with decreasing temperature as n approaches its lower value ≈ 2/3.  相似文献   

16.
We report the syntheses and crystal structures of novel organotin chloride complexes with functional organic substituents from HSnCl3 · 2Et2O ( 1 – 3 ). Whereas Cl3SnCHPhCH2C(O)(CH)2Ph ( 1 ) was synthesized in a traditional route from HSnCl3 · 2Et2O and dibenzylideneacetone, C6H5Cl5O4Sn2 ( 2 ) and C8H9Cl5O4Sn2 ( 3 ) represent products of a condensation reaction of mononuclear organotintrichlorides that comprise both C=C and C=O functional groups and additionally exhibit characteristic intramolecular donor‐acceptor interactions. Due to the condensation, compounds 2 and 3 combine SnCl2 with SnCl3 groups within one molecule.  相似文献   

17.
1‐Isopropylidene‐2‐methylhydrazine ( 1 ), 1‐isopropylidene‐2‐hydroxyethylhydrazine ( 2 ) and 1‐isopropylidene‐2‐formylhydrazine ( 3 ) were synthesized by reaction of the corresponding hydrazine with an excess of acetone in the presence of a drying agent (anhydrous sodium sulfate or barium oxide). All compounds 1 – 3 were characterized by elemental analysis, coupled gas chromatography‐mass spectrometry (GC–MS), multinuclear NMR spectroscopy (1H, 13C and 15N) and vibrational spectroscopy (infrared and Raman). Compounds 1 and 2 are liquid at room conditions and their density was measured by means of a picnometer, however, (at room conditions) compound 3 is a solid and its crystal density and structure were determined by low temperature X‐ray diffraction techniques (monoclinic, P21/n, Z = 4, a = 5.666(1) Å, b = 6.254(1) Å, c = 15.277(4) Å, β = 91.30(2)°, V = 541.2(2) Å3). The structure of hydrazone 3 is discussed in detail and compared to that of monoformylhydrazine. Finally, the (gas phase) structure of compound 3 was optimized using DFT calculations (B3LYP/6‐31+G(d, p)) and its NBO charges are reported.  相似文献   

18.
Graphite is a redox‐amphoteric intercalation host and thus capable to incorporate various types of cations and anions between its planar graphene sheets to form so‐called donor‐type or acceptor‐type graphite intercalation compounds (GICs) by electrochemical intercalation at specific potentials. While the LiCx/Cx donor‐type redox couple is the major active compound for state‐of‐the‐art negative electrodes in lithium‐ion batteries, acceptor‐type GICs were proposed for positive electrodes in the “dual‐ion” and “dual‐graphite” cell, another type of electrochemical energy storage system. In this contribution, we analyze the electrochemical intercalation of different anions, such as bis(trifluoromethanesulfonyl) imide or hexafluorophosphate, into graphitic carbons by means of in situ X‐ray diffraction (XRD). In general, the characterization of battery electrode materials by in situ XRD is an important technique to study structural and compositional changes upon insertion and de‐insertion processes during charge/discharge cycling. We discuss anion (X) and cation (M+) intercalation/de‐intercalation into graphites on a comparative basis with respect to the Mx+Cn and Cn+Xn stoichiometry, discharge capacity, the intercalant gallery height/gallery expansion and the M–M or X–X in‐plane distances.  相似文献   

19.
The synthesis routes of Gd(HCO3)3 · 5H2O and Ho(HCO3)3 · 6H2O, which are the only known bicarbonates of rare earth metals, were refuted and the published crystal structures were discussed. Because of the structural relationship of Ho(HCO3)3 · 6H2O to rare earth nitrate hexahydrates, 1 the synthesis of holmium nitrate hydrate was considered and the crystal structure of Ho(NO3)3 · 5H2O was solved by single crystal X‐ray diffraction measurements. Ho(NO3)3 · 5H2O was determined to crystallize in the triclinic space group P1 (no. 2) with a = 6.5680(14) Å, b = 9.503(2) Å, c = 10.462(2) Å, α = 63.739(14)°, β = 94.042(2)° and γ = 76.000(16)°. The crystal structure consists of isolated [Ho(H2O)4(NO3)3] polyhedra and non‐coordinating water molecules. It is isotypic to other rare earth nitrate pentahydrates.  相似文献   

20.
Cd2(PO2NH)4 · 8H2O crystallizes in space group P21/c (no. 14), Z = 2, with a = 648.5(2), b = 1070.5(2), c = 1328.7(3) pm and β = 103.11(3) °. The structure, isotypic with M2(PO2NH)4 · 8H2O (M = Mg, Mn, Co, Ni, Zn), is composed of Cd2+ and (PO2NH)44? ions as well as crystal water molecules. The P4N4 rings of the (PO2NH)44? ions exhibit a slightly distorted chair‐2 conformation, which has been described by torsion angles, displacement asymmetry parameters and puckering parameters. The tetrametaphosphimate anions are connected forming layers. These layers are linked solely by hydrogen bonds, forming a three‐dimensional network.  相似文献   

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