共查询到20条相似文献,搜索用时 15 毫秒
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The Crystal Structure of NH4VO2F2 Crystals of NH4VO2F2 are monoclinic, space group Pc, a = 4.814(2), b = 11.434(3), c = 7.214(2) Å, β = 108.84(4)°. Z = 4. The VO2F-ion is polymeric. The structure consists of endless chains of strongly distorted octahedra with common edges. Two adjacent polyhedra are linked by an asymmetrical oxygen bridge (bond lengths 1.74 and 2.21 Å) and an asymmetrical fluorine bridge (bond lengths 1.97 und 2.21 Å). The terminal V? O- and V? F-distances are 1.55 and 1.86 Å, respectively. 相似文献
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Crystal Structure of Potassium Monomethylcarbonate Potassium monomethylcarbonate KCH3CO3 was obtained from reaction of dimethylcarbonate with potassium hydroxide in methanole. The crystal structure was determined (triclinic, P1 (no. 2), Z = 2, a = 380.9(2) pm, b = 558.9(3) pm, c = 985.3(3) pm, α = 100.71(2)°, β = 90.06(3)°, γ = 92.48(3)°, V = 205.9(2) · 106 pm3, wR(F2) = 0.054, wRobs(F) = 0.022). Structural relations between potassium monomethylcarbonate and potassium hydrogencarbonate are discussed. 相似文献
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Ch. Hebecker 《无机化学与普通化学杂志》1972,393(3):223-229
The crystal structure of thallium trifluoride The crystal structure of TlF3 has been determined form single crystal diffraction data. The unit cell is orthorhombic, space group Pnma≠D, with a = 5.825, b = 7.024, c = 4.851 Å, Z = 4. Each Tl has 8 nearest F-neighbours. The Tl–F distances range from 2.09 to 2.49 Å. 相似文献
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W. Jeitschko 《Monatshefte für Chemie / Chemical Monthly》1966,97(5):1472-1476
Zusammenfassung MoAlB kristallisiert orthorhombisch mit den Zellabmessungena=3,212,b=13,985,c=3,102 Å. In der Raumgruppe Cmem-D
2h
17
besetzen alle drei Atomarten die Punktlage 4 c) mity
Mo=0,0891,y
Al=0,304,y
B=0,465.
Mit 1 Abbildung 相似文献
MoAlB crystallizes with an orthorhombic unit cell having the lattice constantsa=3.212,b=13.985,c=3.102 Å. The three kinds of atoms all occupy the position 4 c) of space group Cmcm-D 2h 17 withy Mo=0.0891,y Al=0.304,y B=0.465.
Mit 1 Abbildung 相似文献
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Bernt Krebs 《无机化学与普通化学杂志》1970,378(3):263-272
Zirconium(IV) chloride crystallizes in the monoclinic space group P2/c with a = 6.361, b = 7.407, c = 6.256 Å β = 109.30°, Z = 2. The single crystal X-ray structure analysis shows the structure to consist of an arrangement of [ZrCl4/2Cl2] zig-zag chains. Within the chains each Zr atom has an octahedral environment; the octahedra are linked through sharing edges, the two terminal Cl ligands being mutually in cis-position. The structure is closely related to those of TcCl4, PtI4 and MoOCl3. The Zr? Cl bond lengths are 2.655 (bridge), 2.498 (bridge) and 2.307 Å (terminal) ZrBr4, HfCl4, and HfBr4 are isostructural with ZrCl4 相似文献
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The crystal structure of NaBiO2 NaBiO2 crystallizes monoclinic in C with a = 7.394, b = 7.262, c = 5.886 Å, β = 127.7°; Z = 4. Parameters were refined by least-squares (555 hkl with |h?l| = 0 to 4; R = 10.9%). Angular groups [BiO2] are twisted by 180°, forming chains [BiO2/2O2/2] along [001]. The MADELUNG part of lattice energy (MAPLE) is calculated and discussed. 相似文献
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Klaus Stwe 《无机化学与普通化学杂志》2000,626(3):803-811
The Crystal Structure of PrTe2 X‐ray diffraction single‐crystal structure analysis of PrTe2 prepared by chemical vapour transport reactions starting with praseodymium and tellurium in the presence of trace amounts of iodine also revealed superstructure reflections indicating just as for CeTe2 a (2 × 2 × 2)‐supercell of the basic anti‐Fe2As‐type structure instead of a (2 × 2 × 1)‐supercell as for LaTe2. In contrast to LaTe2 with monoclinic symmetry (space group P1c1), PrTe2 crystallizes tetragonal in the space group P4 with the lattice parameters a = 896.80(5) pm and c = 1811.9(1) pm (Z = 16). The doubling of the c‐lattice parameter compared to LaTe2 is observed due to different polyanionic structural motifs in the heights z ≈ 0 and z ≈ 1/2. These are a herringbone pattern of [Te2] dumbbell pairs (motif A; a topology which is also found in LaTe2), isolated square four‐membered [Te4] rings in z ≈ 0 (motif B) and additionally rectangular four‐membered [Te4] rings in z ≈ 1/2 (motif C). Though CeTe2 and PrTe2 are crystallizing isotypically, there are distinct differences in the interatomic distances within the polyanionic Te layers and resulting from these also a different topology of the structural motif C. The individual structural elements are causing a diffraction pattern, which is all in all to be explained by a statistical superposition of the different elements in form of microdomains. 相似文献
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Crystal Structure of non‐aqueous Melaminium Chloride Melaminium chloride was obtained as colorless, needle‐shaped, single crystalline material from solid state reactions between melamin and ammonium chloride. The structure of [C3N6H7]Cl was refined by single crystal X‐ray diffraction: I2/m, Z = 8, a = 852.87(4), b = 1704.4(1) c = 918.44(4) pm and β = 92.165(6)°. The crystal structure contains melaminium ions stacked to columns along [100] and linked via N‐H···N bridges to form bands along [001]. Both of the two distinct chloride ions are stabilized by six hydrogen bonds through distorted trigonal prismatic arrangements of hydrogen atoms to yield a supramolecular structure. 相似文献
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The Crystal Structure of SrCaCrF7 By solid state reaction of the component fluorides at elevated temperature single crystals of SrCaCrF7 were obtained (a = 792.3(2), b = 724.7(2), c = 986.1(2) pm; space group Pnma, Z = 4). The X‐ray structure determination confirmed isotypism with the Ca2AlF7 type of structure: Isolated octahedra [CrF6]3— (mean Cr‐F: 189.7 pm) are opposed by infinitely netted planar cations [SrFCa2/2]3+ which contain “independent” F atoms 3‐coordinated by alkaline earth atoms only. The Sr atoms prefer (at a level of 80%) the 8‐fold, the Ca atoms the 7‐fold coordinated positions between the octahedra. 相似文献
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Zusammenfassung RhHg2 kristallisiert tetragonal mita=4,551 Å,c=2,998 Å,c/a=0.6588 in der Raumgruppe P 4/mmm. Die Phase ist isotyp mit -PtHg2.
The structure of RhHg2 was found to be tetragonal; the unit cell ofa=4,551 Å,c=2,998 Å,c/a=0,6588 belongs to the space group P 4/mmm. RhHg2 is isostructural with -PtHg2.相似文献
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F. Folger 《无机化学与普通化学杂志》1975,411(2):111-117
Crystal Structure of BaTeO3 Crystals of BaTeO3 were prepared from melts. BaTeO3 is isotropic with KClO3 and crystallizes in the monoclinic system, space group P21/m. The lattice parameters are a = 4.633, b = 5.952, c = 7.308 Å, β = 111.2°. The formula unit is 2. The crystal structure was determined by Patterson synthesis, refined by least squares and confirmed by (Fo — Fc) synthesis. Using isotropic temperature corrections the R-value of 1072 observed reflections calculated as 0.748, and anisotropic the R-value as 0.702. In BaTeO3 tellurium forms with three oxygen atoms pyramidal TeO3-groups, barium has to oxygen atoms the coordination 7+2. The TeO3 groups are not linked one with another, but with the BaO9 polyhedrons by common corners and edges, the latter are linked one with another only by common edges. 相似文献
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Zusammenfassung TaNi2 kristallisiert im MoSi2-Typ. 相似文献
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Helmut Paulus Karl Schlögl Walter Weissensteiner 《Monatshefte für Chemie / Chemical Monthly》1982,113(6-7):767-780
X-ray crystal structure analyses of stereoisomeric 1,2-dimethyl and diphenyl 1,2-diferrocenyl ethanes (1,2) as well as of 1,1,2,2-tetraferrocenyl ethane (3) showed that racemic (threo) and meso (erythro)2 adopt conformations with antiperiplanar arrangement of the ethane H-atoms (andC
2 andC
i symmetry, resp.), whereas1 and3 prefer the synclinal (skew) conformations. In3 the torsional angle between the ethane H-atoms is increased to appr. 90°;3 represents a chiral structure withC
2 symmetry.For the conformation of tetraferrocenyl ethane (3) in solutionC
2 symmetry could be deduced from the13C-nmr. spectra.The conformations of the diferrocenyl ethanes are discussed and compared with those of corresponding alkyl and aryl ethanes.
Herrn Prof. Dr.E. Ziegler (Graz) mit den besten Wünschen zum 70. Geburtstag gewidmet. 相似文献
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The Crystal Structure of LiInSe2 The crystal structure of LiInSe2 has been determined from single crystal data (β-NaFeO2 type, space group Pna21 (No. 33), a = 718.3(2), b = 839,8(3), c = 678.1(2) pm; 375 hkl, R = 0.032; R(w) = 0.029). The mean values 253.6 pm of the bond distances Li? Se are larger than calculated, the distances In? Se (256.8 pm) are equal with the calculated values. The structure is discussed in relation to the analogous LiBIIIC2VI compounds. 相似文献
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F. Paltauf 《Monatshefte für Chemie / Chemical Monthly》1968,99(4):1277-1280
Ohne Zusammenfassung 相似文献
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O. Schwomma A. Preisinger H. Nowotny A. Wittmann 《Monatshefte für Chemie / Chemical Monthly》1964,95(6):1527-1537
Zusammenfassung Die Kristallstruktur von Mn11Si19 wird mit Hilfe vonFourier-und Differenz-Fourier-Synthesen bestimmt (RaumgruppeD
2d
8
). Die Struktur ist gekennzeichnet durch eine einfache Unterzelle der Manganatome, die eine diamantoide Anordnung ähnlich wie die Ti-Atome im TiSi2-Typ bilden. Die Elementarzelle von Mn11Si19 besitzt gegenüber der Unterzelle die 11fachec-Achse.
Mit 4 Abbildungen 相似文献
The crystal structure of Mn11Si19 has been determined by means of Fouriersynthesis (space group D 2d 8 ). The structure type is characterized by a simple subcell for the manganese atoms, forming a diamond-like arrangement similar to that of the titanium atoms in TiSi2. With respect to thec-axis the unit cell of Mn11Si19 corresponds to eleven (11) subcells.
Mit 4 Abbildungen 相似文献
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Zusammenfassung Im Bereich der homogenen Mischphase V1,00–0,47Al0,00–0,53 wird die metastabile Kristallart V3Al erfaßt. V3Al besitzt Cr3O-Struktur (-Wolfram-Typ). Lückenlose Mischreihen von V3Al mit V3Sb und Nb3Sn werden nachgewiesen. Unter gleichen Bedingungen, Homogenisierung bei 1000 und 1100°C, treten dagegen mit V3Si, V3Ge und Nb3Al Mischungslücken auf.Mit 1 Abbildung 相似文献