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1.
Interatomic distances in Hf3Sb and h-Ta3Ge (Fe3P-type structure, space group ) have been determined by crystal structure refinements based on Rietveld-type full-profile analyses of Guinier-H:agg X-ray powder film intensity data. The results, together with data from the recently refined Hf3As and Ta3As structures, are included in a survey of coordination and bonding in Fe3PTi3PV3STa3As-type compounds. It is shown that the trends in atomic coordination observed can be explained in terms of an interplay of d-d and d-p electronic interactions. 相似文献
2.
The crystal structure of the κ-carbide in the FeWC system has been refined from neutron powder diffraction data using the Rietveld profile analysis method. κ-(FeWC) is isostructural with κ-(CoWC); space group ; unit cell dimensions a = 7.7982(2)Å, c = 7.8298(4) Å. The structure refinement indicates substitution at two of the tungsten sites, and 46% vacancies at one of the carbon sites. The composition corresponds to the formula Fe3+xW10?xC4?y, with x = 0.57(3) and y = 0.46(1). 相似文献
3.
Single crystals of BaTiF5 and CaTiF5 were obtained by the Czochralski and Bridgman techniques, respectively. The crystal structures were determined by X-ray diffraction; BaTiF5: Å, c = 7.670(3)Å; CaTiF5: Å, b = 6.614Å, c = 7.696(3)Å, β = 115.16(3)°. Both structures are characterized by the presence of either branched or straight chains of TiF6 octahedra. BaTiF5 contains the unusual dimeric unit (Ti2F10)4?. Magnetic susceptibility measurements were performed on both compounds in the temperature range 4.2 to 300 K, however, no evidence for magnetic interactions between the Ti3+ moments were observed. 相似文献
4.
A.M. El Balkhi M. Zanne C. Gleitzer A. Courtois 《Journal of solid state chemistry》1976,18(3):293-297
This compound is prepared, within sealed metallic tubes at 1000°C, through different reactions between components of the FeFe2O3NaFeO2 system. It is black and weakly hygroscopic and gives two forms, α and β, according to oxygen pressure values.The examination of a crystal of the α form leads to a trigonal cell (space group or R32) with a = 3.047 Å and c = 31.04 Å for the hexagonal cell (Z = 4). The structure is described as a stacking of alternate cationic and anionic planes with a succession of 12 cationic planes: 3 × FFMM (F, plane including Fe; M, mixed plane including ).α-NaFe2O3 is paramagnetic above 94°K with μeff = 5.40; it is a semiconductor, n type, with E = 0.18 eV. Above 1050°C it dissociates into NaFeO2 and sodic wustite, which oxidizes easily.The β form is probably a polytype with a hexagonal cell (a = 3.045Å, c = 15.55 Å) with six cationic planes. 相似文献
5.
Rudolf Allmann Wolfgang Henke Peter Krommes Jörg Lorberth 《Journal of organometallic chemistry》1978,162(3):283-287
The molecular and crystal structure of tris(bistrimethylsilylamin)thallium was determined by means of single-crystal X-ray spectroscopy: in the space group P1c with a = 16.447(7), c = 8.456(7) Å; and Dc = 1.149 g cm?3 two molecules are located in the unit cell. The compound is isomorphous to the analogues Fe[N(SiMe3)2]3 or Al[N(SiMe3)2]3, respectively, which show a propellar-twist of the Si2N-groups versus the plane of the metal atom and the three nitrogen-atoms: Tl(N)3/Si2N 49.1°; SiNSi 122.6°; NSiC 111.8°; CSiC 107.1°; TlN 2.089 Å;; SiN 1.738 Å;; 1.889 Å;. 相似文献
6.
The structure of (Ph3SiN)2C has been determined by single crystal X-ray diffraction. The structure was solved by direct methods and refined to R = 0.071 for 593 independent diffractometer data. The crystals are rhombohedral, R with a = b = c 18.201(20) Å, α = β = γ = 48.82(2)°, and Z = 4. The three crystallographically independent molecules each have linear SiNCNSi chains lying along the crystallographic threefold axes; in two of the molecules the central carbon atom lies on a centre of symmetry. Principal mean bond lengths and angles are: Si, 1.696(25); SiC, 1.846(20); NC, 1.164(30); CC, 1.387(14) Å; CSi, 108.2(6); and CSiC, 110.8(6)°. 相似文献
7.
Gerhard Thiele Günther Liehr Ekkehard Lindner 《Journal of organometallic chemistry》1974,70(3):427-435
The molecular structure of [(C6H5)3P]2Pd(C3H4) has been determined from three-dimensional X-ray diffraction data. The crystal belongs to the triclinic system, space group P, with two formula units in a cell of dimensions: a = 19.475(2), b = 10.204(2), c = 18.341(2) Å, α = 108.46(2), β = 85.46(1), and γ = 118.80(1)°.One of the olefinic bonds of allene is coordinated to the palladium atom: PdC(1) = 2.118(9) and PdC(2) = 2.067(8) Å. The coordinated allene is no longer linear, the C(1)C(2)C(3) angle being 148.3(8)°. The C(1)C(2) distance is 1.401(11) Å, whereas the uncoordinated bond remains unchanged [C(2)C(3) = 1.304(12) Å]. The Pd, P(1), P(2), C(1) and C(2) atoms lie almost in the same plane. 相似文献
8.
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
9.
The structure of [Pt2Cl(CO) (μ-Ph2PCH2PPh2)2] [PF6] was determined by -ray methods and refined to = 0.082, using diffractometric intensities of 5646 independent reflections. The crystals are monoclinic, space group 21/, = 12.919(3), = 15.576(6), = 25.151(5)Å, β = 94.82(3)°, = 4. They are built of octahedral hexafluorophosphate anions and dinuclear platinum(I) cations. The latter contain PtCl and PtCO fragments linked to one another by a PtPt σ-bond and by two bridging bis(diphenylphosphino)methane ligands. The platinum atoms are in square planar environments and the dihedral angle between the two coordination planes is 40.1°. Selected bond lengths are: PtPt 2.620(1), PtCl 2.384(5), PtC 1.89(3) and PtP 2.291(5) – 2.308(5)Å. 相似文献
10.
The crystal structures of SiPb2S4 and SiPb2Se4 were determined from three dimensional X-ray diffraction data collected with Mo radiation. Both structures are monoclinic with space group and 4 formula units per unit cell. Lattice dimensions for SiPb2S4 are a = 6.4721(5) Å, b = 6.6344(9) Å, c = 16.832(1) Å, and β = 108.805(7)°. For SiPb2Se4, a = 8.5670(2) Å, b = 7.0745(3) Å, c = 13.6160(3) Å, and β = 108.355(3)°. The Si is tetrahedrally coordinated to S and Se with SiS about 2.10 Å and SiSe about 2.27 Å. The structural framework can be described as consisting of trigonal prisms of S or Se atoms which form a prismatic tube by sharing the triangular faces. These tubes in turn share edges to form corrugated sheets, with the unshared edges projecting alternately on each side of the sheet. The structures are very similar but not identical. In the sulfide one Pb is in sevenfold coordination and the other crystallographically independent Pb is in eightfold coordination. The PbS distances range from 2.82–3.50 Å. In SiPb2Se4 both Pb atoms are in sevenfold coordination. PbSe distances range from 2.97 to 3.54 Å. In the sulfide the Pb atoms form a zig-zag chain within the channels formed by the prismatic tubes while in the selenide they are in a straight line. 相似文献
11.
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
12.
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
13.
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
14.
The phase relations in the In2O3A2O3BO systems at elevated temperatures [A: Fe or Ga, B: Cu or Co]
The phase relations in the In2O3Fe2O3CuO system at 1000°C, the In2O3Ga2O3CuO system at 1000°C, the In2O3Fe2O3CoO system at 1300°C, and the In2O3Ga2O3CoO system at 1300°C were determined by means of a classical quenching method. InFeCuO4 (a = 3.3743(4) Å, c = 24.841(5) Å), InGaCuO4 (a = 3.3497(2) Å, c = 24.822(3) Å), and InGaCoO4 (a = 3.3091(2) Å, c = 25.859(4) Å) having the YbFe2O4 crystal structure, In2Fe2CuO7 (a = 3.3515(2) Å, c = 28.871(3) Å), In2Ga2CuO7 (a = 3.3319(1) Å, c = 28.697(2) Å), and In2FeGaCuO7 (a = 3.3421(2) Å, c = 28.817(3) Å) having the Yb2Fe3O7 crystal structure, and In3Fe3CuO10 (a = 3.3432(3) Å, c = 61.806(6) Å) having the Yb3Fe4O10 crystal structure were found as the stable ternary phases. There is a continuous series of solid solutions between InFeCoO4 and Fe2CoO4 which have the spinel structure at 1300°C. The crystal chemical roles of Fe3+ and Ga3+ in the present ternary systems were qualitatively compared. 相似文献
15.
Samples of rhombohedral chromium oxide hydroxide, α-CrOOH, and the deuterated compound, α-CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. The crystallographic data are: α-CrOOH: a = 2.979(5)Å, c = 13.37(2)Å, z = 3, space group (No. 166). α-CrOOD: a = 2.985(4)Å, c = 13.48(3)Å, z = 3, space group R3m (No. 160). Distances found for the hydrogen (deuterium) atoms are: OD···O: 2.57(2) Å; OD: 1.05(2) Å; OH···O: 2.47(1) Å; and OH: 1.16(1) Å, showing large isotope effects. 相似文献
16.
R.B. King 《Journal of organometallic chemistry》1975,100(1):111-125
The molecular structure of [(C6H5)3P]2Pt(C5H8) has been determined from three-dimensional X-ray diffraction data (R = 0.045 for 6033 reflections). The crystal belongs to the triclinic system, space group P, with two formula units in a cell of dimensions: a = 18.557(2), b = 10.216(2), c = 9.647(2) Å, α = 98.29 (3), β = 73.44(2), and γ = 88.34(2)°.One of the olefinic bonds of dimethylallene, which has no adjacent methyl groups, is coordinated to the platinum atom: PtC(1) = 2.108(8), PtC(2) = 2.049(7) Å. The coordinated dimethylallene molecule is no longer linear, the C(1)C(2)C(3) angle being 140.8(8)°, which is significantly smaller than that found in [(C6H5)3P]2Pd(C3H4). The C(1)C(2) distance is 1.430(11) Å, whereas the uncoordinated bond distance is normal [C(2)C(3) = 1.316(11)Å]. 相似文献
17.
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
18.
Walter K. Dean Gary L. Simon Paul M. Treichel Lawrence F. Dahl 《Journal of organometallic chemistry》1973,50(1):193-207
The accidental but intriguing synthesis of acetatobis(triphenylphosphine)dicarbonylmanganese(I), (CH3CO2)Mn(CO)2[P(C6H5)3]2, has been accomplished by the reaction of NaMn(CO)5 with (CH3)3SiCl followed by the addition of triphenylphosphine and acetic acid. A three-dimensional single-crystal X-ray diffraction analysis has shown an octahedral-like molecule containing a symmetrically oxygen-chelating acetate group, the first such group to be reported in a metal carbonyl complex. The two triphenylphosphine ligands occupy mutually trans positions with the two carbonyl ligands possessing the remaining cis sites in the octahedral complex. The compound crystallizes with four molecules in a monoclinic unit cell of space group symmetry and of dimensions a = 17.744(2) Å, b = 9.692(1) Å, c = 20.004(2) Å, and β = 106.195(4)°. The relatively long MnO(acetate) bond lengths [2.066(6) and 2.069(7) Å] and the relatively short MnCO bond lengths [1.701(12) and 1.760(13) Å] and the relatively short MnP(C6H5)3 bond lengths [2.260(3) and 2.275(3) Å], compared to the corresponding MnCO and MnP(C6H5)3 bond lengths in other manganese carbonyl triphenylphosphine complexes, are rationalized on the basis that the acetate ligand in this molecule functions primarily as a σ-donor. 相似文献
19.
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
20.
The crystal structure of NbS3 was determined from single-crystal diffractometer data obtained with MoKα radiation. The compound is triclinic, space group , with: a 4.963(2) Å; b = 6.730(2) Å; c = 9.144(4)Å; α = 90°; β = 97.17(1)°; γ = 90°. The structure is closely related to the ZrSe3 structure type; it shows that the compound can be formulated as Nb4+(S2)2?S2?, in agreement with XPS spectra. The main difference with ZrSe3 is that the Nb atoms are shifted from the mirror planes of the surrounding bicapped trigonal prisms of sulfur atoms to form NbNb pairs (NbNb = 3.04 Å); this causes a doubling of the b axis relative to ZrSe3 and a decrease of the symmetry to triclinic. 相似文献