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1.

Abstract  

The low temperature crystal structure of the complex, Cr(urea)4(H2O)2·3NO3 (1), displays intriguing pseudosymmetry that complicates the structure determination. 1 crystallises in the centrosymmetric monoclinic space group P21/c with Z = 8 and Z′ = 2; a = 18.3338(4) ?, b = 16.5472(4) ?, c = 13.9252(3) ? and β = 106.3260(10)°, V = 4054.19(16) ?3. The two symmetry independent [Cr(urea)4(H2O)2]3+ ions in the asymmetric unit both feature coordinated urea (O=C(NH2)2) and lie on general positions. A further six independent nitrate anions complete the structure. The unit cell is primitive but the two Cr3+ ions are related by a pseudo translation of ?, ?, 0. The deviation from a truly C-centred cell is clear from an examination of geometry of the urea ligands and the hydrogen bonds which they form. The identification of the space group in this case is described and methods for quantifying the degree of deviation from a C-centred cell discussed.  相似文献   

2.
The crystal structure of the mineral byelorussite-(Ce) NaMnBa2Ce2Ti2Si8O26(F,OH) · H2O belonging to the joaquinite group was solved and refined to R = 0.033 based on 4813 reflections with I > σ2(I). The parameters of the orthorhombic unit cell are a = 22.301(4) Å, b = 10.514(2) Å, c = 9.669(2) Å, V = 2267.1(8) Å3, sp. gr. Ama2, and Z = 4. The structure is composed of three-layer sheets, which consist of dimers of edge-sharing Ti octahedra located between isolated four-membered [Si4O2] rings. The sheets are linked to each other by Mn 5-vertex polyhedra to form a heteropolyhedral framework. Large cavities in the framework are occupied by Na 6-vertex polyhedra, Ba 11-vertex polyhedra, and REE 9-vertex polyhedra.  相似文献   

3.
The Vickers hardness of the (010) and (001) planes in (NH4)2Ni(SO4)2 · 6H2O (ANSH) crystals has been measured. Anisotropy hardness of the first kind is revealed for the (010) plane in ANSH. The hardness anisotropy coefficient k 2 was determined to be 1.5. The temperature dependence of the microhardness of the (001) face of ANSH crystals was investigated in the temperature range from 20 to 80°C. The character of fracture of the (100), (010), and (001) planes during indentation with a spherical indenter has been qualitatively determined.  相似文献   

4.
The complex [(NH2)2CSSC(NH2)2]2[OsBr6]Br2 · 3H2O is synthesized by the reaction of K2OsBr6 with thiocarbamide in concentrated HBr and characterized using electronic absorption and IR absorption spectroscopy. Its crystal structure is determined by X-ray diffraction. The crystals are orthorhombic, a = 11.730(2) Å, b = 14.052(3) Å, c = 16.994(3) Å, space group Cmcm, and Z = 4. The [OsBr6]2? anionic complex has an octahedral structure. The Os-Br distances fall in the range 2.483–2.490 Å. The α,α′-dithiobisformamidinium cation is a product of the oxidation of thiocarbamide. The S-S and C-S distances are 2.016 and 1.784 Å, respectively. The H2O molecules, Br?ions, and NH2 groups of the cation are linked by hydrogen bonds.  相似文献   

5.
The compound Rb2[(UO2)2(CrO4)3(H2O)2] · 4H2O was studied by X-ray diffraction. The crystals are monoclinic, a = 10.695(2) Å, b = 14.684(3) Å, c = 14.125(3) Å, β = 108.396(4)°, sp. gr. P21/c, Z = 4, V = 2104.9(7) Å3, and R = 0.0491. The main structural units are layers consisting of [(UO2)2(CrO4)3(H2O)2]2? anions belonging to the crystal-chemical group A 2 T 2 3 B 2M 2 1 (A = UL 2 2+ , T 3 and B 2 are CrO 4 2? , and M 1 is H2O) of uranyl complexes. The uranium-containing layered groups are held together by electrostatic interactions with rubidium cations, as well as by hydrogen bonds with the participation of inner- and outer-sphere water molecules.  相似文献   

6.
Large single crystals of rubidium nickel hexahydrate Rb2Ni(SO4)2 · 6H2O (RNSH) of optical quality were grown for the first time. The atomic structure of RNSH crystals was refined. A comparative analysis of the crystal structures of (M 1+)2Ni(SO4)2 · 6H2O, where M 1+ is K, Rb, or Cs, was performed. The solubility curve of RNSH in water was measured. The optical and thermogravimetric properties of RNSH were investigated. The internal defect structure of RNSH crystals was studied by X-ray topography.  相似文献   

7.
The compound [UO2(NO3)2(H2O)2] · 2C12H18O was synthesized and studied by IR spectroscopy and X-ray diffraction. The structure consists of the neutral island groups [UO2(NO3)2(H2O)2], which belong to the crystal-chemical group AB 01 2 M 1 2 (A = UO2 2+, B 01 = NO3, M 1 = H2O) of uranyl complexes, and 1-adamantyl methyl ketone molecules. The characteristic features of the association of the complexes [UO2(NO3)2(H2O)2] and 1-adamantyl methyl ketone molecules in the crystal structure via hydrogen bonds are considered with the use of Voronoi-Dirichlet polyhedra.  相似文献   

8.
The crystal structure of (HPhen)2S2O8 · 2H2O is studied using X-ray diffraction. The crystals are monoclinic, a = 23.716(5) Å, b = 10.220(2) Å, c = 13.103(3) Å, β = 128.03(2)°, V = 2501.6(9) Å3, Z = 4, space group C2/c, and R = 0.0745 for 1579 reflections with I > 2σ(I). The crystal is built of S2O 8 2? centrosymmetric anions, HPhen + cations, and molecules of crystallization water. Hydrogen bonds link the structural units into chains. Within a chain, stacking interactions are observed between the phenanthroline rings (the interplanar spacing between the rings is 3.8 Å, and the dihedral angle between their planes is 8°). The data of IR spectroscopy confirm the formation of the N(Phen)-H bond.  相似文献   

9.

Abstract  

Reaction of Ph2SnCl2 with 1,3-bis(3,5-dimethylpyrazol-1-yl)-2-propanol (L) in a 1:1 ratio yields L(SnPh2Cl2)2 adduct, which partly hydrolyzes to the title complex (C25H31Cl3N4OSn, Mr = 628.58) during crystal growing in the air. The title complex is of monoclinic, space group P21/n with a = 9.0338(9), b = 17.890(1), c = 17.340(1) ?, β = 95.533(1)o, V = 2798.9(5) ?3, Z = 4, Dc = 1.492 Mg/m3, λ(Mo) = 0.71073 ?, μ = 1.224 mm−1, F(000) = 1272, R = 0.023, wR = 0.054 for 4212 observed reflections with I ≥ (I). The crystal structure indicates that there is no direct interaction between the pyrazolyl ligand and the tin atom, but this complex forms a supramolecular structure through weak intermolecular C–H⋯Cl and O–H⋯Cl hydrogen bonds.  相似文献   

10.

Abstract  

Water-soluble derivative of formononetin, [Na(H2O)1.5][Na(H2O)3.5] X2·2H2O(X = 4′-methoxy-7-hydroxyisoflavone-3′-sulfonate) was synthesized by sulfonation reaction. It was characterized by IR, 1H NMR and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis showed that the title compound crystallized in a triclinic space group P-1 with cell parameters a = 6.9642(15) ?, b = 13.343(3) ?, c = 20.634(5) ?, α = 107.115(3)˚, β = 93.121(4)˚, γ = 91.911(3)˚, V = 1827.3(7) ?−3, D c  = 1.575 Mg m 3, Z = 2. There are two conformers of 4′-methoxy-7-hydroxyisoflavone-3′-sulfonate anions, two kinds of sodium cations, five coordinated water molecules and two lattice water molecules in the crystal structure. The sodium atoms coordinated with the oxygen atoms from water molecules, hydroxyl groups and sulfo-groups to form a Na–O coordinated network. Aromatic π···π stacking interactions and hydrogen bonding existed in the crystal structure of title compound, which together with coordinated interactions and electrostatic interactions between sodium cations and anions sulfonates C16H10O4SO3 lead to the moieties into a three-dimensional network.  相似文献   

11.

Abstract  

The compound [Ni(RPOEt)2(C2H5OH)2](ClO4)2 (1) [RPOEt = bis{(diphenylphosphinyl)methyl}ethyl phosphinate] has been prepared in the form of single crystals and characterized by elemental and thermal analyses, IR spectroscopy and by a single crystal X-ray diffraction study. The complex crystallizes in the triclinic P[`1] P\bar{1} space group with a = 9.8773(5), b = 13.741(1), c = 14.287(1) ?, α = 64.313(9), β = 70.280(5), γ = 89.973(7)o, V = 1620.5(2) ?3, and Z = 1. The nickel(II) atom in 1, situated at the centre of symmetry, is coordinated by four oxygen atoms from two RPOEt ligands and two oxygen atoms from two ethanol molecules in a slightly distorted octahedral environment. The third phosphoryl-oxygen atom from the phosphinate ligand is hydrogen bonded to the oxygen atom of the ethanol molecule coordinated to nickel(II). The complex [Ni(RPOEt)2(C2H5OH)2]2+ cations are linked by the C–H···O hydrogen bonds into one-dimensional chains and by the composite π···π and C–H···π phenyl interactions into a final three-dimensional structure.  相似文献   

12.
Abstract  A three-dimensional lanthanide metal-organic coordination polymer Yb3(BDC)4.5(DMF)2(H2O)3 · (DMF)2 has been synthesized by the reaction of the lanthanide metal ion (Yb3+) with 1,4-benzenedicarboxylic acid (H2BDC) under mild condition. The compound crystallizes in the triclinic system, space group PI with unit cell parameters a = 10.7428(9) Å, b = 11.2786(9) Å, c = 26.172(2) Å, α = 85.060(2)°, β = 88.1060(10)°, γ = 62.3670(10)°, V = 2798.9 (4) Å3, Z = 2. The crystal structure exhibits one-dimensional channels along the [011] direction. The fluorescent results showed that there were two emission peaks at 375 and 420 nm when the compound was excited by a 235 nm excitation. Graphical Abstract  The preparation, X-ray structure and luminescent property are presented for a new lanthanide metal-organic coordination polymer Yb3(BDC)4.5(DMF)2(H2O)3 · (DMF)2.   相似文献   

13.
The molecular structure of [(tBu)2Al(-OC6H5-2-Me)]2 has been determined. Both the ortho-tolyl methyl groups are oriented towards Al(2). The intramolecular steric interaction between the ortho-methyl groups and the tert-butyl ligands results in the geometry about the bridging oxygen being significantly distorted while the geometries about the aluminum centers show a distortion from tetrahedral that is less than the sterically less hindered [(tBu)2Al(-OPh)]2. Crystal data: group C2/c, a = 13.733(3) Å, b = 15.135(3) Å, c = 15.420(3) Å, = 104.24(3), V = 3106(1) Å3, Z = 4, R = 0. 0612, wR2 = 0.1787.  相似文献   

14.
Aquanitrilotris(methylenephosphonato)dirubidium is a 3D coordination polymer with a layer structure. Space group \(P\bar 1\), Z = 2; a = 8.0380(3) Å, b = 9.0522(4) Å, and c = 10.7837(4) Å; α = 113.252(4)°, β = 105.391(3)°, and γ = 96.182(3)°. Rb atoms populate two symmetrically inequivalent positions with c.n. = 8 and 10; significant difference in O–Rb–O angles in the coordination polyhedra is indicative of the ionic type of Rb–O bonds. In the crystal packing, molecules are connected by not only coordination bonds but hydrogen bonds as well.  相似文献   

15.
The reaction of 2,6-dimethylpyridine with SbCl3 and HCl affords the title compound, the structure of which is ascertained by X-ray diffraction. The unit cell consists of one bridged Sb2Cl82− anion and two 2,6-dimethylpyridinium cations. The trivalent antimony ion is bonded not only directly to chlorine anions, but also is coordinated with chlorine anions by secondary bonds. In the crystal, there exists infinite coordinated chains of [Sb2Cl8] n 2n anions running along the a axis, which link 2,6-dimethylpyridinium cations by N-H…Cl hydrogen bonds.  相似文献   

16.
The solid solution NH4Al0.62Cr0.38(SO4)2 · 12H2O was studied by X-ray diffraction. The crystal structure was determined in a series of the maximal subgroups Pa3? > R3? > P1? > P1. Reflections forbidden in sp. gr. Pa3? are indicative of symmetry lower than cubic. In the centrosymmetric models under consideration, all sulfate groups are oppositely oriented with respect to each other. In non-centrosymmetric sp. gr. P1, four of the eight sulfate groups have the same orientation, whereas the other four groups are oriented in an opposite direction.  相似文献   

17.

Abstract  

The novel supramolecular networks based on Keggin-type polyoxoanion, formulated (Hpy)3[PMo12O40]·2(py) has been synthesized hydrothermally and determined by X-ray diffraction. The compound crystallize in Monoclinic, system with space groups and cell parameters, P2 1 /n, a = 10.9370(2) ?, b = 19.586(3) ?, c = 12.5500(2) ?, β = 98.618(2)°, V = 2657.8(6) ?3. Organic fragments and Keggin anions are connected via N–H···N, N–H···O contacts to form interesting 1D zigzag chain. The molecule is stabilized in solid state by electrostatic forces and intermolecular hydrogen-bonding interactions to give the confirmation of guest [PMo12O40]3− inserting in organic host.  相似文献   

18.
Abstract  The molecular structure of [Cu2(MeCN)2(μ-tpy)2][BPh4]2 has been determined. The two terpyridine ligands coordinate to the same Cu(I) center in a bidentate configuration, in which the copper adopted a distorted tetrahedral geometry with the four nitrogen donors. The third ring of each terpyridine ligand forms a bridge with a second Cu(I) center, whose tetrahedral coordination sphere is completed by two acetonitrile ligands. The resulting structure represents a section of a double helix. Crystal data: space group C2/c, a = 27.202(5), b = 12.995(3), c = 23.409(5) ?, β = 123.13(3)°; V = 6930(2) ?3, Z = 4, R = 0.0613, wR 2 = 0.0946. Graphical Abstract  The molecular structure of [Cu2(MeCN)2(μ-tpy)2][BPh4]2 has been determined. The terpyridine ligands coordinate in a bidentate fashion to the same Cu center and monodentate to a second Cu center resulting in a double helical structural motif.   相似文献   

19.
Single crystals of the compound Na3(H3O)[UO2(SeO3)2]2 · H2O (I) have been synthesized, and their structure has been investigated using X-ray diffraction. Compound I crystallizes in the triclinic system with the unit cell parameters a = 9.543(6)Å, b = 9.602(7)Å, c = 11.742(8)Å, α = 66.693(16)°, β = 84.10(2)°, γ = 63.686(14)°, space group P \(\bar 1\), Z = 2, and R = 0.0734. The uranium-containing structural units of the crystals are [UO2(SeO3)2]2? chains, which belong to the crystal-chemical group AB 2 B 11 (A = UO 2 2+ , B 2 = SeO 3 2? , B 11 = SeO 3 2? ) of the uranyl complexes. The structures of the compounds containing the [UO2(SeO3)2]2? anionic complexes are compared.  相似文献   

20.
Crystals of UO2CrO4(C5NH5COO)2(H2O)] · 2H2O are synthesized and their structure is studied by X-ray diffraction. The compound crystallizes in the triclinic crystal system. The unit cell parameters are as follows: a = 7.0834(10) Å, b = 10.6358(14) Å, c = 12.9539(17) Å, α = 75.096(2)°, β = 74.490(2)°, and γ = 80.657(2)°; V = 904.1(2) Å3, space group P \(\bar 1\), Z = 2, and R = 0.026. The structure is built of [UO2CrO4(C5NH5COO)2(H2O)]2 centrosymmetric dimers, which are linked into a framework by a system of hydrogen bonds involving inner-sphere and outer-sphere water molecules. The coordination number of the U(VI) atom is seven, and the coordination polyhedron is a pentagonal bipyramid with the oxygen atoms of the uranyl group, two chromate groups, two molecules of isonicotinic acid, and a water molecule at the vertices. The crystal chemical formula of the [UO2CrO4(C5NH5COO)2(H2O)]2 dimer is represented as AB 2 M 3 1 , where AB 2 M 3 1 , where A = UO 2 2+ , B 2 = CrO 4 2? , and M 1 = = C5NH4COOH and H2O.  相似文献   

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