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1.
The ESR.-spectra of the radical anion of syn-1, 6; 8, 13-bis-oxido-[14]annulene have been recorded. The hyperfine structure of the electrolytically generated anion (solvent: N, N-dimethylformamide; gegenion: Et4N) is that of an unassociated species; on the other hand, evidence of strong ion-pairing can be derived from the spectra of chemically prepared anions (solvent: 1,2-dimethoxyethane; gegenion: K⊕ or Na⊕). The distribution of the n-spin population confirms the conclusion previously drawn for the radical anion of 1,6-oxido-[70]annulene that the overall effect of the oxygen bridging is electron repelling.  相似文献   

2.
The crystal structure of the Bis[propylenthioacetale] of 2,4-Dioxo-3-[1,3],6 u -[1,3,4,6],9 u -[1,3]tribenzaspiro-[5.5]undecaphane has been determined by three-dimensional X-ray data (4312 reflections) and refined to anR-value of 0.035. The cell constants of the triclinic cell (P ) are:a=13.598 Å,b=11.195 Å,c=10.280 Å, =77.21°, =69.23°, =71.51°. The shape of the central benzene ring is found to be chair-like, the two terminal benzene rings boat-like.  相似文献   

3.
Zusammenfassung Die Kristallstruktur der Verbindung Ge5O[PO4]6 wurde auf Grund dreidimensionaler Einkristalldaten ausWeissenberg-Aufnahmen ermittelt und nach der Methode der kleinsten Quadrate verfeinert: Raumgruppe ;a=7,994±0,004 undc=24,87±0,01 Å;Z=3; 467 unabhängige Reflexe;R=0,086.Die Kristallstruktur wird aus singulären [GeO6]-Oktaedern und [Ge2O7]-Doppeltetraedern aufgebaut, die über [PO4]-Tetraeder zu einem dreidimensionalen Strukturverband vernetzt sind. Die mittleren Abstände betragen: Ge[6]–O=1,863, Ge[4]–O=1,704 und P–O=1,525 Å.
The crystal structure of Ge5O[PO4]6
The crystal structure of Ge5O[PO4]6 has been determined and refined by least-squares, using three-dimensional x-ray data fromWeissenberg-photographs: space group ;a=7.994±0.004 andc=24.87±0.01 Å;Z=3; 467 independent reflections;R=0.086.The crystal structure consists of isolated [GeO6] octahedra and [Ge2O7] double tetrahedra which are linked by [PO4] groups forming a three-dimensional network. The average interatomic distances are: Ge[6]–O=1.863, Ge[4]–O=1.704 and P–O=1.525 Å.


Mit 2 Abbildungen  相似文献   

4.
The crystal structure of Si5O[PO4]6 has been determined and refined by least-squares, using three-dimensional X-raydata fromWeissenberg photographs: space group R 3;a=7.869 andc=24.138 Å;Z=3; 418 independent reflections;R=6.0%. The crystal structure consists of isolated [SiO6] octahedra and [Si2O7] groups which are linked by [PO4] tetrahedra forming a three-dimensional network. The average interatomic distances are: Si[6]?O=1.768, Si[4]?O=1.607 and P?O=1.52i Å. The compound is isotypic with Ge5O[PO4]6.  相似文献   

5.
On the Structure of Li8PbO6 For the first time single crystals of Li8PbO6 have been prepared by heating of mixtures of Na2PbO3 and Li2O [Ag-cylinders, 650°C, 150 d]. The structure [382 I0(hkl), four circle diffractometer PW 1100, ω/2Θ-scan, MoKα, R = 3.07%, Rw = 3.00%, space group R3 ; a = 555.09(4), c = 1564.13(17) pm, Dx = 4.28 g · cm?3, Dpyk = 4.24 g · cm?3, Z = 3] is characterized by the motive of a hexagonal-closed O2? packing. Half of the octahedral sites are occupied by Pb4+ and Li+ and half of the tetrahedral sites only by Li+. The Madelung Part of Lattice Energy, MAPLE, and the Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.  相似文献   

6.
Synthesis and Structures of the Gold Cluster [Au16(AsPh3)8Cl6] Reduction of Ph3AsAuCl with NaBH4 in ethanol yields the gold cluster [Au16(AsPh3)8Cl6]. It can be crystallized from dichloromethane/diisopropyl ether in form of dark red, light sensitive crystals with the space group P21/n and a = 1777.68(8), b = 3372.7(1), c = 2696.2(1)pm, β = 94.166(6)°, Z = 4). The inner skeleton of the 16 Au atoms consists of a centered icosahedron of which one of the corners binds to three additional Au atoms forming a tetrahedron pendent. The shortest Au–Au distances of 264.3 to 266.6 pm correspond to the bonds to the three external Au atoms. Within the icosahedron the distances between the central atom and the peripheral atoms (273.0–279.1 pm) are distinctly shorter than the distances between the peripheral atoms (283.6–299.0 pm).  相似文献   

7.
The crystal structure of lithium enneagermanate, Li4[Ge9O20], has been determined and refined by least-squares, using three-dimensional single-crystal data. The compounds crystallizes with monoclinic symmetry (a=12.43,b=8.00,c=7.49 Å, =91.0o; C2–C2 3) building up a framework structure which exhibits some similarity with the structures of Li2[Ge4O9] and Li2[Ge7O15]. Out of the 18 Ge-atoms in the unit cell 14 are surrounded tetrahedrally by oxygen showing an average distance of 1.757 Å; the remaining 4 Ge-atoms are octahedrally coordinated with an average distance of 1.886 Å.
Die Kristallstruktur des Lithium-enneagermanats Li4[Ge9O20]
Zusammenfassung Die Kristallstruktur von Lithium-enneagermanat Li4[Ge9O20] wird an Hand dreidimensionaler Einkristalldaten ermittelt und nach der Methode der kleinsten Quadrate verfeinert (R=0,083). Die monoklin kristallisierende Verbindung (a=12,43;b=8,00;c=7,49 Å; =91,0o; C2–C2 3) besitzt eine Gerüstruktur, die einen ähnlichen Aufbau wie Li2[Ge4O9] und Li2[Ge7O15] zeigt. Von den 18 Ge-Atomen in der Elementarzelle liegen 14 in tetraedrischer Koordination mit einem mittleren Ge–O-Abstand von 1,757 Å vor; 4 Ge-Atome sind oktaedrisch umgeben, mit einem mittleren Ge–O-Abstand von 1, 1886 Å.


Mit 3 Abbildungen

Herrn Professor Dr.O. Hromatka zum 65. Geburtstag gewidmet.  相似文献   

8.
9.
Zusammenfassung Die Kristallstruktur der Verbindung Li2[Ge7O15] wird mit Hilfe dreidimensionaler Patterson- und Fourier-Synthesen bestimmt und nach der Methode der kleinsten Quadrate verfeinert. Die Gitterparameter der orthorhombischen Elementarzelle (Pbcn — D 2h 14 ) betragen:a=7,36,b=16,76 undc=9,69 Å. Die Struktur enthält stark gewellte Schichten aus [GeO4]-Tetraedern, die über [GeO6]-Oktaeder zu einem dreidimensionalen Gerüst verknüpft sind; sie läßt sich durch die Formel Li2[Ge(Ge2O5)3] charakterisieren. Als mittlere Ge–O-Abstände werden erhalten: 1,735 Å (K.Z. 4) und 1,893 Å (K.Z. 6).
The crystal structure of Li2[Ge7O15]
The crystal structure of Li2[Ge7O15] has been determined by means of three-dimensional Patterson and electron density syntheses, and refined by least-squares method. The lattice parameters of the orthorhombic unit cell (Pbcn-D 2h 14 ) are:a=7.36,b=16.76 andc=9.69 Å. The crystal structure contains strongly puckered layers of [GeO4]-tetrahedra linked by [GeO6]-octahedra to form a three-dimensional framework; the structure can be characterized by the formula Li2[Ge(Ge2O5)3]. The averaged Ge–O-distances are found to be: 1.735 Å (c. n. 4) and 1.893 Å (c.n. 6).


Mit 1 Abbildung  相似文献   

10.
Crystal Structure of Li8PbO6 The crystal structure of Li8PbO6 (Li8TbO6 structure, space group R3 ? C, hexagonal lattice constants a = 554.3, c = 1 563 pm) has been refined by profile analysis of a neutron diffraction pattern. Deviations from ideal tetrahedral and octahedral coordination of lithium atoms are similar to those described for Li8SnO6.  相似文献   

11.
Zusammenfassung Die Kristallstruktur von Li6[Si2O7] wird mit Hilfe von Patterson-Projektionen und dreidimensionalen Fourier-Synthesen sowie nach der Methode der kleinsten Quadrate bestimmt. Die Gitterparameter der tetragonalen Elementarzelle (P421m-D 2d 3 ) betragen:a=7,715;c=4,88 Å. Die Verbindung zählt zu den Sorosilicaten mit isolierten [Si2O7]-Gruppen. Die Lithiumionen weisen gegenüber Sauerstoff die Koordinationszahlen 4 und 5 auf. Als mittlere Abstände [Å] wurden ermittelt: Si-O : 1,64 Li-O : 1,95 [4] und 2,18 [5].
The crystal structure ofLi 6[Si 2 O 7]
The crystal structure of Li6[Si2O7] has been determined by means of Patterson projections, 3-dimensional Fourier syntheses and the least-squares method. The lattice parameters of the tetragonal unit cell (P421m-D 2d 3 ) area=7.715 andc=4.88 Å. The compound belongs to the sorosilicates having isolated [Si2O7]-groups. The coordination numbers of the lithium ions are 4 and 5. The average interatomic distances were found to be: Si-O : 1,64 Å; Li-O : 1.95 [4] and 2.18 [5] Å.


Mit 3 Abbildungen  相似文献   

12.
The Crystal Structure of CsTcO4 CsTcO4 crystallizes orthorhombic with a = 5.727, b = 5.921 and c = 14.34 Å. Z = 4, space group Pnma (Nr. 62, I.T.). The metal positions were refined by single crystal data, the oxygen positions first determined: the CsTcO4 structure is a slight distortion of the scheelite arrangement (parameters: see text). The MADELUNG Part of Lattice Energy, MAPLE, ?Mean Effective Ionic Radii”?, MEIR, and Effective Coordination Numbers, ECoN, are calculated and discussed.  相似文献   

13.
The title compound is monoclinic, space group Pc (No. 7),a=6.549 (1),b=9.094 (1),c=11.426 (2) Å, =126.78 (1)° andZ=2. Its crystal structure has been refined from 1 323 single crystal X-ray reflections toR=0.131. The structure of K6Ge2O7 is very similar to that of K6Co2O7 and K6Si2O7 both of which have been reported to be centrosymmetric, space group P21/c. While the angle at the bridging oxygen atom is 180° in the latter compounds, it is 157° in K6Ge2O7.
  相似文献   

14.
The crystal structure of the compound K2Ba[Ge4O9]2 has been determined by means of three-dimensional X-ray data resulting a finalR-value of 0.034. The lattice constants of the trigonal unit cell ( ) are:a=11.729 (I) andc=19.278 (3) Å. There is a close structural relationship to the tetragermanates K2Ge4O9 and BaGe4O9. The new compound also consists of three-membered rings built up by [GeO4] tetrahedra, which are linked by [GeO6] octahedra forming a three-dimensional network.According to their powder diagrams the following compounds are isostructural to K2Ba[Ge4O9]2: Na2Ba[Ge4O9]2, Rb2Ba[Ge4O9]2, Na2Sr[Ge4O9]2 and K2Sr[Ge4O9]2.  相似文献   

15.
16.
Crystal structure of AgIIF[AgIIIF4] For the first time dark brown single crystals of mixedvalent AgF[AgF4] were isolated under solvothermal conditions out of anhydrous HF/F2. The compound crystallizes in a new type of structure, triclinic with a = 499.9(2) pm, b = 1108.7(5) pm, c = 735.7(3) pm, α = 90.05(3)°, β = 106.54(4)°, γ = 90.18(4)°, spcgr. P1¯ — Ci1 (No. 2) and Z = 4.  相似文献   

17.
18.
Magnesium amide crystallizes tetragonally with a = 10.37, c = 20.15 Å, c/a = 1.943; space group I41/a2/c2/d, and Z = 32. The nitrogen has a distorted cubic close-packed arrangement. Magnesium occupies a quarter of the tetrahedral interstices. The structure is dominated by the somewhat complicated distribution of magnesium and hydrogen. The hydrogen tends to be as far away from the neighboured magnesium as possible.  相似文献   

19.
The hydrazinium monofluoride N2H5F crystallizes with orthorhombic symmetry, space group P212121,a=4.592 Å,b=8.217 Å,c=12.341 Å, and 8 formula units. The structure was determined by the permutation method in projection, and by the three-dimensionalPatterson function, refined by Full-Matrix-Least-Squares (R=0.056). The structure consists of N2H5 +- and F?-ions, bonded with hydrogen bonds N?H ... N and N?H ... F. Each N2H5 + ion is surrounded by four F?-ions and two nitrogen atoms of two different N2H5 + ions. Each F? ion is connected with four different N2H5 + ions.  相似文献   

20.
Synthesis and Crystal Structure of the Tellurium Nitride Chloride [Te11N6Cl26] The title compound has been prepared by the reaction of tellurium tetrachloride with tris(trimethylsilyl)amine in boiling toluene. Pale yellow crystals of the composition [Te11N6Cl26]2 · 9C7H8 are obtained by cooling of the saturated solution. The compound was characterized by IR spectroscopy and by a crystal structure determination. Space group P1 , Z = 1, structure solution with 5912 observed unique reflections, R = 0.043. Lattice dimensions at ?50°C: a = 1636.2, b = 1692.7, c = 1704.1 pm, α = 60.57°, β = 69.59°, γ = 64.29°. The dominating structural element of the nitrchloride are planar Te5N3 units forming two four-member Te2N2 rings which are condensed together. Two asymmetric units [Te11N6Cl26] are linked by a centre of symmetry; the intercalated toluene molecules are without binding interactions.  相似文献   

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