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1.
β-TeVO4 crystallizes in the monoclinic system with the space group and the parameters: a = 4.379 Å, b = 13.502 Å, c = 5.446 Å, and β = 91.72°. Vanadium occupies the center of a square pyramid of oxygens, an extra oxygen is at VO = 2.77 Å. These distorted octahedra share corners forming puckered sheets parallel to (010). The sheets are held together by [Te2O6]4? groups in which tellurium is one-side coordinated by four oxygen atoms. 相似文献
2.
NH3(MoO3)3 crystallizes with hexagonal symmetry, space group , lattice constants a = 10.568 Å, c = 3.726 Å, and Z = 2. The crystal structure has been determined by Patterson synthesis and refined assuming isotropic temperature factors to a final conventional R value of 0.085. The structure shows a three-dimensional arrangement built up of double chains of distorted MoO6 octahedra, parallel to the [001] direction. The octahedral double chains are linked among each other through common oxygen atoms. In addition to the shared oxygen atoms, each molybdenum is coordinated to one terminal oxygen. MoO distances range from 1.645 to 2.378 Å and OMoO angles from 74.3 to 114.3°. These results are consistent with the fact that molybdenum in high-valence states shows octahedral coordination with terminal oxygens. 相似文献
3.
The crystal structure of β-BiNbO4 has been determined from three-dimensional X-ray data. The crystals are triclinic with a = 7.611 Å, b = 5.536 Å, c= 7.919 Å, α = 89.88°, β = 77.43°, γ = 87.15°, Z = 4, space group . Full-matrix least-squares refinement using isotropic temperature factors has reached R = 0.122 for 642 visually estimated reflections.The structure contains unusual sheets of formula [NbO4]∞ in which the NbO octahedra are joined at four vertices such that the two free ones are cis. NbO distances range from 1.80 to 2.31 Å. The bismuth atoms hold these sheets together and are coordinated to eight oxygens in the form of a very distorted square antiprism.Structurally, β-BiNbO may be considered an antiferroelectric, ferroelastic member of the BaMF4 prototype family. 相似文献
4.
Michael Laing Magriet J. Nolte Eric Singleton Erwin van der Stok 《Journal of organometallic chemistry》1978,146(1):77-86
The crystal structure of [(C8H12)6H3Me)(OC6H4Me)2} {P(OCH2)3CMe}] has been determined. a 18.32, b 18.98, c 9.35 Å, U 3251 Å3, Pn21a, Z = 4, R = 0.048, 2541 observed data.The coordination about the iridium atom is distorted trigonal bipyramidal; the two phosphorus atoms are equatorial, the σ-bonded carbon is axial, and the bidentate cyclooctadiene is bonded axialequatorial. The IrC(axial) bonds are longer than the IrC(equatorial) bonds: 2.22, 2.26; 2.17, 2.19 Å. The IrC(σ) bond length is 2.19 Å, not significantly different from the formally π-bonded C to Ir distances. The IrP lengths of 2.201 and 2.240 Å and the PIrP angle of 108.7° are normal. The longer IrP bond is in the five-membered chelate ring. The inertness to substitution is discussed. 相似文献
5.
H. D. Hausen K. Sille J. Weidlein W. Schwarz 《Journal of organometallic chemistry》1978,160(2):411-419
Trimethylgallium reacts with acetic acid in a molar ratio yielding methylgallium diacetate, CH3Ga(OOCCH3)2? The structure is determined by vibrational spectroscopy and the crystal structure is described. Methylgallium diacetate crystallizes in the monoclinic space group P21/c with lattice constants a 776.5, b 1428.9, c 1406.3 pm, β 91.87° and eight formula units per cell. The monomers are linked together by acetate groups forming polymeric, waved layers. Besides the bridging acetate there are also “free” acetate groups coordinated at the distorted trigonal-bipyramidal coordinated Ga(1) atom. A second gallium atom Ga(2) is coordinated distorted tetrahedrally, the acetate groups bonded to Ga(2) being all bridging. The mean intermolecular distances are: GaC 194.6 pm, Ga(1)Oapical 215.3 pm, Ga(1)Oeq(bridge) 194.3 pm, Ga(1)Oeq(free) 187.3 pm, Ga(2)O 191.3 pm, CC 151.5 pm, CO 119.4 pm, CO 131.1 pm, CO 127.3 pm. 相似文献
6.
Kjell Waltersson 《Journal of solid state chemistry》1979,28(1):121-131
The crystal structure of has been determined and refined on the basis of three-dimensional X-ray diffractometer data (MoKα radiation). The structure is monoclinic, a = 7.710(2), b = 19.474(7), c = 7.216(2)Å, β = 116.75(1)°, V = 967.5Å3, Z =8, space group Cc (No. 9). The final R and Rw were 0.0295 and 0.0300, respectively, for 1356 independent reflections and 117 variables.The structure contains two crystallographically different VOF5 octahedra linked so as to form complex chains. Two non-equivalent octahedra share one FF edge, forming V2O2F8 doublets. Two F atoms, connected to different V atoms within the doublet, form an edge in the adjacent equivalent V2O2F8 unit thus continuing the chain. The VO distances are 1.583(7) and 1.595(7) Å. The VF distances are in the range 1.881-2.205 Å, mean value: 1.989 Å. The H2O group is a crystal water molecule. 相似文献
7.
The series of compounds M2EuRuO6 (M = Ca, Sr, Ba) has been studied by 151Eu Mössbauer spectroscopy. X-Ray data show them to be structurally derived from the ABO3 perovskite lattice, but only the Ba compound gives positive evidence to suggest ordering of the cations. The 151Eu resonance shows magnetic hyperfine splitting at 4.2 K. The Ru5+OEu3+ORu5+ exchange takes place by admixture of low-lying excited states into the diamagnetic J = 0 ground-state of the Eu3+. The Curie temperatures are approximately 18, 31, and 42 K for the Ca, Sr, and Ba compounds. Detailed analysis shows that substantial disorder of cations occurs, being quite large for Ca, <8% for Sr, and <5% for Ba. However, it appears that considerable canting of the Ru5+ spins takes place in the Ba compound immediately below the Curie temperature as a result of the disorder and low anisotropy at the Ru sites. This effect is much reduced in the more distorted Sr compound. 相似文献
8.
The crystal structure of RbSbF2SO4 has been determined on a single crystal (R = 0.078 for 710 reflections). The structure shows sulfate anions distorted by the SOSb bonds. The antimony atom is from an SbF2 unit. This antimony dihalogen is from the family of the compounds which are in MX3SbX3 (M = Al, Ga, In) (X = Cl, Br) systems. 相似文献
9.
The crystal structure of the 42-Å subcell of a layer structure with approximate composition Ba4Nb2S9
J.S. Swinnea H. Steinfink L.E. Rendon-Diazmiron M. Gomezdaza 《Journal of solid state chemistry》1983,46(3):367-372
Platy crystals from the products of a mixture 4 Bas : 2 Nb : 5 S reacted at 1000°C have cell constants a = 13.754(3) Å, c = 83.73(2) Å, . The reciprocal lattice had a pronounced subcell with dimensions a = 6.877(1) Å, c = 41.84(1) Å, same space group. Three dimensional X-ray diffraction data were collected using monochromatized Mo Kα radiation and of 5051 measured intensities 1892 were considered observed. From the set of observed intensities 611 reflections having all even indices were used to refine the crystal structure of the 42 × 7-Å subcell. The final R = 0.036 and ωR = 0.052 for the 611 observed amplitudes and R = 0.046, ωR = 0.052 for all 711 amplitudes of the subcell. The structure is based on the stacking of hexagonal BaS3 layers with the sequence DABABDBCBCDCACAD. The D layer denotes a disordered level and occurs at and . The different letters for the ordered layers are based on the Ba positions in that layer. The Nb ions occupy octahedral interstices and form a unit of three face sharing octahedra parallel to c. The column is terminated above and below by disordered levels. The NbNb distances are 3.22 Å, causing displacement of Nb from the centers of the two outside octahedra. One Ba is in the center of a triangular orthobicupola formed by 12 S atoms. The other Ba is in the center of a hexagon of 6 S with 3 additional S above this layer forming of a cuboctahedron. The lower half consists of a disordered layer of atoms. The NbS distances are 2.279, 2.433, and 2.683 Å; BaS distances vary between 3.1 and 3.5 Å. The subcell content based on the ordered structure only is Ba12Nb9S36. The placement of disordered Ba and S at , and levels of the subcell leads to the unlikely composition Ba16.5Nb9S42. The ordered structure most likely has a composition Ba4Nb2S9, z = 36, so that the subcell composition should be Ba18Nb9S40.5. The completely ordered structure has not been solved. 相似文献
10.
The structure of Mn(NO)3PPh3 has been analyzed by single-crystal X-ray diffraction. It shows a tetrahedral geometry with essentially linear nitrosyl groups, and an eclipsed configuration around the MnP bond. Average distances and angles are: MnN 1.686(7) Å, MnP 2.315(2) Å, NO 1.165(10) Å, PC 1.815(4) Å, MnNO 177.2(7)°, PMnN 103.6(2)°, NMnN 114.7(4)°. Final R factor 7.3% for 2064 non-zero reflections. The structure of the five-coordinate nitrito complex Mn(NO)2(ONO)(PEt3)2 is also mentioned briefly. 相似文献
11.
Ce6Mo10O39 crystallizes in the triclinic system with unit-cell dimensions (from single-crystal data) a = 10.148(5), Å, b = 18.764(6), Å, c = 9.566(5), Å, α = 103.12(7)°, β = 78.07(7)°, γ = 107.69(7)°, and space group . The structure was solved using direct methods with 3113 countermeasured reflections (MoKα radiation), and refined using Fourier and least-squares techniques to a conventional R of 0.039 (ωR = 0.047). Ce6Mo10O39 has a structure that consists of isolated MoO4 tetrahedra together with one corner-shared pair of tetrahedra, linked to irregular eight-coordinate Ce(III) polyhedra. The average MoO distance of 1.77 Å, and average CeO distance of 2.52 Å are in good agreement with previously reported values. 相似文献
12.
The formula of a new compound isolated in the LaOsO system has been established by means of crystal structure determination. There are two La3Os2O10 units in a face-centered monoclinic unit cell (S.G. ); a = 7.911(2) Å, b = 7.963(2) Å, c = 6.966(2)Å, β = 115.76(2)°;. For 1082 intensities, collected on an automated single-crystal diffractometer, the final R value was 0.025 after absorption corrections. The structure consists of isolated Os2O10 clusters composed of two edge-shared OsO6 octahedra. These dimeric units are connected together by two types of La3+ ions in eightfold coordination. In view of the OsOs distance inside the pair (2.462 Å), La3Os2O10 provides an example of metal-metal bonding involving a transition metal in a half-integral formal oxidation state of 5.5. 相似文献
13.
M. Bouchdoug A. Courtois R. Gerardin J. Steinmetz C. Gleitzer 《Journal of solid state chemistry》1982,42(2):149-157
This compound is obtained in several ways, at 900°C, from the components of the FePO system when the oxygen pressure is made suitable, or from Fe3(PO4)2 + Fe + Fe2O3 in a sealed tube under vacuum. It crystallizes under these latter conditions with a trace of FeCl2. The cell is monoclinic; a = 6.564(1), b = 11.271(2), c = 9.383(2) Å, β = 103.95 (2)°, with Z = 4, group . The structure is determined thanks to the use of a direct method and Fourier synthesis and is refined to R = 0.033. The PO4 tetrahedra are isolated; the iron fills four crystallographic sites: three are more or less distorted octahedra, the fourth is a trigonal bipyramid. The oxyphosphate character is ascertained by the presence of some oxygen atoms connected to iron only, with, moreover, a low site potential. This compound is paramagnetic above 90°K. Its Mössbauer spectrum exhibits four doublets in good agreement with the structure; in order to identify which one corresponds to the hexahedral site, the phase Fe3Zn(PO4)2O has been prepared, but its Mössbauer spectrum, in spite of the zinc affinity for the V coordination, shows that two sites are modified, which does not allow conclusions to be made. 相似文献
14.
R. Brec G. Ouvrard M. Evain P. Grenouilleau J. Rouxel 《Journal of solid state chemistry》1983,47(2):174-184
PV2S10 was obtained by heating the elements in stoichiometric proportions at 490°C in evacuated Pyrex tubes. The crystal symmetry is monoclinic, space group , with the unit cell parameters a = 12.734(8)Å, b = 7.349(7)Å, c = 23.662(4)Å, β = 95°22(1), V = 2205(4)Å3, and Z = 8. The structure was solved from 2269 independant reflexions, and anisotropic least squares refinement gave R = 0.036 with 236 variables. The structure can be described as made of [V2S12] units forming endless chains themselves linked, two by two, by [PS4] tetrahedra. In these units each vanadium is surrounded by eight sulfur atoms (mean dVS = 2.459Å) arranged in a distorted bicapped triangular prism. Two of these prisms shared a rectangular face to form [V2S12] groups, in which intercationic distances implied vanadium-vanadium bonds (mean dVV = 2.852(2)Å). Between the infinite double chains, only SS weak van der Waals' bonds exist. More than two thirds of the sulfur atoms are present as [SS]?II pairs, (mean dSS = 2.015Å); the rest are S?II anions. 相似文献
15.
16.
The crystal structures of the apatites Ba10(PO4)6F2(I), Ba6La2Na2(PO4)6F2(II) and Ba4Nd3Na3(PO4)6F2 (III) have been determined by single-crystal X-ray diffraction. All three compounds crystallize in a hexagonal apatite-like structure. The unit cells and space groups are: I, a = 10.153(2), c = 7.733(1)Å, Å, ; III, a = 9.786(2), c = 7.281(1)Å, . The structures were refined by normal full-matrix crystallographic least squares techniques. The final values of the refinement indicators Rw and R are: I, Rw = 0.026, R = 0.027, 613 observed reflections; II, Rw = 0.081, R = 0.074, 579 observed reflections; III, Rw = 0.062, R = 0.044, 1262 observed reflections.In I, the Ba(1) atoms located in columns on threefold axes, are coordinated to nine oxygen atoms; the Ba(2) sites form triangles about the F site and are coordinated to six oxygen atoms and one fluoride ion. The fluoride ions are statistically displaced ~0.25 Å from the Ba(2) triangles. This displacement of the F ions is analogous to the displacement of OH ion in Ca10(PO4)6(OH)2.The structures of II and III contain disordered cations. In II there is disorder between La and Na in the column cation sites as well as triangle sites. In III, Nd and Na ions are ordered in the column sites, but there is disorder among Ba and the remaining Nd and Na ions in the triangle sites to give an average site population of . The coordination of the rare earth ions and Na ions in the ordered column sites are nine and six oxygens, respectively, in accord with the greater charge of the rare earth ions as compared with Na. The F ions in both II and III suffer from considerable disorder in position, and their locations are not precisely known. 相似文献
17.
The crystal structure of SnC2O4 has been determined by X-ray single-crystal techniques and refined to R = 0,018 for 1139 reflections. The cell is monoclinic, space group with Z = 4 formula units, the parameters being a = 10,375(3)Å. b = 5,504(2)Å, c = 8,234(3)Å, β = 125,11(2)°. The oxalato groups, located on symmetry centers, are chelated to two Sn atoms through one oxygen on each carbon atom, giving rise to an infinite string (SnC2O4)n. The Sn(II) atom is one-side bonded to four oxygen atoms with two SnO bonds of 2,232(2) Å and two of 2,393(2) Å. The tin atom is in a distorted trigonal bipyramid SnO4E, the lone pair E occupying one of the apices of the equatorial trigonal base of the polyhedron. Crystal structure comparison with disodium bisoxalatostannate(II), Na2Sn(C2O4)2, permits one to deduce SnC2O4 by crystallographic shear operation of periodicity. Na2Sn(C2O4)2 can be described as an intergrowth of SnC2O4 and Na2C2O4 structures and consldered as the first member of a new series Na2Sn1+n(C2O4)2+n with n integer ? 0. 相似文献
18.
G. Eulenberger 《Journal of solid state chemistry》1984,55(3):306-313
The new compound Tl6[Ge2Te6] was prepared by thermal synthesis from the elements. The material is triclinic, space group , with a = 9.471(2), b = 9.714(2), c = 10.389(2) Å, α = 89.39(1), β = 97.27(1), γ = 100.79(1)°, and Z = 2. The crystal structure was determined from single-crystal intensity data measured by means of an automated four-circle diffractometer and refined to an R value of 0.053 for 1831 observed reflections. Tl6[Ge2Te6] is characterized by Ge2Te6 units with GeGe bonds which are linked into a three-dimensional structure by Tl atoms coordinated to essentially six Te atoms. The most important mean distances are Å, Å, and Å. The lone 6s electron pairs of the thallium(I) atoms exhibit significant stereochemical activity. Tl6[Ge2Te6] represents a new structure type. 相似文献
19.
Paul S. Haradem Bertrand L. Chamberland Lewis Katz Alain Gleizes 《Journal of solid state chemistry》1977,21(3):217-223
A single crystal study of Ba3Pt2O7 shows that the structure tolerates a variable composition which can be written Ba3Pt2+xO7+2x. The crystal studied has a hexagonal cell of dimensions a = 10.108 ± 0.006 Å and c = 8.638 ± 0.009 Å, and a probable space group . The density determined by water displacement is 7.99 g/cm3; the theoretical density for Ba3Pt2O7 is 7.94 g/cm3. The structure was determined from the set of 401 observed independent reflections obtained from 5189 reflections measured by automated counter methods. Refinement on F was carried to a conventional R of 8.0%. The structure has barium-oxygen layers with an essentially four-layer stacking sequence of the double hexagonal (ABAB) type. Platinum is found mainly in face-sharing octahedra, but is also distributed over some sites in which the coordination is nearly square planar and other sites in which the coordination is trigonal prismatic with three PtO bond lengths of 2.00 Å and three long PtO distances of 2.65 Å. The platinum with planar coordination is 0.08 Å from the plane of the four oxygen atoms. 相似文献
20.
The structure of a carbon monoxide adduct of cobalt-exchanged zeolite A, CO5.25Na1.5A · 1.5CO, has been determined by Rietveld neutron profile refinement. The space group used was with a = 24.1557(14) Å; the final Rpw was 13.8%. All exchangeable cations are located in sites adjacent to the 6-rings; 3.75 of the cobalt cations sit 0.4 Å inside the β-cage (Co(2)) and are arranged tetrahedrally about the eight 6-ring sites in the β-cage. The sodium cations (Na(1)) reside just inside the α-cage in sites similar to those found previously for zeolites 3A, 4A, and 5A. The remaining 1.5 cobalt cations (Co(1)) are located in sites similar to those for sodium, but they are also coordinated to the carbon monoxide molecules, which lie on, or close-to, the threefold axis which passes through the 6-ring. Inside the β-cage there is a tetrahedral aluminum complex of AlO4 type, the oxygen atoms (O1) of which point toward six rings not occupied by cobalt cations, Co(2). Each of the oxygen atoms of this complex is involved in a hydrogen bond (2.83 Å) to the 6-ring oxygen O(3). Approximately of these bonds are of type O1H···O(3) and of type O1···HO(3). 相似文献