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1.
C15H34BrN, monoclinic, P 21/m, a = 21.603(9), b = 7.261(3), c = 5.636(2) Å, β = 86.85(2)°, Z = 2, V = 882.72 Å3, Dx = 1.160 g/cm3, μ(MoKα) = 2.45 cm−1, λ(MoKα) = 0.71069 Å. The structure of this cationic surfactant was solved with Patterson methods and refined to R = 0.091 for 2057 measured reflections. The dodecyl chains are slightly screwed around their chain axes. The hydrocarbon chains are statistically disordered. The polar regions satisfy the mirror plane which is by remaining parts only statistically fulfilled. In the process of structure refinement statistical disorder has been included by separation of some atom positions. The sublattice of the hydrocarbon chains is nearly O⟂ with as = 5.14, bs = 7.26, cs = 2.52 Å.  相似文献   

2.
The crystal and molecular structure of an interesting cage compound is described. Crystal data: C48H36N6O6·(CH3)2CO; monoclinic; space group: P2 1 /n; a = 14.948(3) Å, b = 15.079(3) Å, c = 19.539(4)Å, = 93.93(3)°, V = 4394(2)Å3; and Z = 4.  相似文献   

3.
2-Nitroresorcinol is triclinic, space group P; at –100°Ca=7.083(2),b=7.696(2),c=6.607(2) Å, =74.61(2), =77.81(2), =68.64(2)°,V=320.8(2) Å3,D x=1.606(1) g cm–3,Z=2. The two hydroxyl groups form symmetric intramolecular hydrogen bonds to the nitro group. The molecules pack in stacks held together by - interaction with adjacent molecules in a head-to-tail arrangement.  相似文献   

4.
5.
The composition, structure, and properties of smectites of different origins have been studied by X-ray diffraction, IR spectroscopy, scanning electron microscopy, and microprobe analysis. The results showed that nontronites of different origins differ in composition, properties, morphology, and IR spectroscopic characteristics. Depending on the degree of structural order and the negative charge of iron-silicate layers in nontronites, the shift of the 001 reflection to smaller angles as a result of impregnation with ethylene glycol (this shift is characteristic of the smectite group) occurs differently. The calculated values of the parameter b (from 9.11 to 9.14Å) are valid for the extreme terms of dioctahedral smectite representatives: nontronites.  相似文献   

6.
Reaction of lithiated 1,1,2,2-tetramethyl-disilyl-1,2-bis[2-(4,5,6,7,8-pentahydro)-azulene] (I) with ZrCl4 in THF at –78°C gave the new {1,1,2,2-tetramethyl-disilyl-1,2-bis[2-(4,5,6,7,8-pentahydro)-azulenyl]}rcub;zirconium dichloride complex (II) in reasonable yield. It crystallizes in the orthorhombic Pnma space group with a = 19.792(4), b = 18.493(3), c = 7.105(1) Å and Z = 4. The complex (II) is symmetric with respect to a mirror plane passing through the Zr and the two Cl atoms. The coordination geometry of Zr atom is that of a distorted tetrahedron formed by the two Cl atoms and the centroids of the two cyclopentadienyl rings of the pentahydroazulenyl moieties. The Zr—Cl bond lengths are 2.451(2) and 2.419(2) Å and the Zr—C distances vary in the range 2.437(4)–2.588(4) Å.  相似文献   

7.
4-Iodoacetophenone azine crystallizes in the space group Pbcn with cell parametersa = 34.5187(19), b = 7.2638(4), and c = 6.3736(3) Å. The azine shows a gauche conformation with regard to the N—N bond and the phenyl rings are twisted in a way that leads to the largest possible twist between the benzene rings of each azine. This azine conformation allows for intermolecular arene–arene T-contacts between pairs of benzene rings and these double-T contacts involve only molecules within the same layer. All azines are perfectly colinear within each layer and this results in a quadrilateral kite-shaped arrangement of iodine atoms at the interface of each layer. The iodine-iodine distances within each layer are 4.5 and 5.1 Å, and the three unique angles of the kite-shaped quadrilaterals are 97.1, 76.9, and 88.8°. The iodine atoms in adjacent layers pack such that atoms of one layer fill the square interstices of the next layer. The distances between iodine atoms in adjacent layers are 4.5 and 4.1 Å. The C—I bonds are not orthogonal to the I-planes and the direction of the molecules in adjacent layers causes a deviation of about 40° from colinearity  相似文献   

8.
A new iron-niobium phosphate, Fe0.5Nb1.5(PO4)3, has been prepared and studied by X-ray diffraction, electron microprobe analysis, IR spectroscopy, and neutron powder diffraction. On the basis of X-ray powder data, it was found that the synthesized phosphate crystallizes into the sp. gr. R $\bar 3$ c and corresponds to the structural type of sodium-zirconium phosphate NaZr2(PO4)3. The structure was refined by the Rietveld method based on a powder neutron diffraction experiment. The obtained phosphate belongs to complex niobium orthophosphates and has a framework structure with a zero framework charge.  相似文献   

9.
The crystal structure of calcium succinate monohydrate, Ca(C4H4O4)·H2O, has been determined by single crystal X-ray diffraction. The crystals are monoclinic witha=11.952(2),b=9.691(2),c=11.606(2)Å, =108.81(1)°, space group C2/c,Z=8,V=1272.49 Å3,d m =1.80, andd c =1.818 Mg m–3. The structure was refined by full-matrix least-squares techniques toR=0.027,R w =0.040, for 829 reflections with13(I). Ca is coordinated to seven oxygen atoms, and the coordination polyhedron is best described as a pentagonal bipyramid. One carboxylate group in the succinate ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion is bonded to three different Ca ions, forming a four-membered chelate ring with one Ca ion and unidentate bridge bonds to two other Ca ions. The other carboxylate group is bonded to two Ca ions through unidentate bonds. The structure is highly polymeric. The general structural features are nearly identical to those of calcium adipate monohydrate.Certain commercial materials and equipment are identified in this paper to specify the experimental procedure. In no instance does such identification imply recommendation or endorsement by the National Institute of Standards and Technology or the ADA Health Foundation or that the material or equipment identified is necessarily the best available for the purpose.  相似文献   

10.
The pseudohexagonal crystal structure of the mineral catapleiite Na1.5Ca0.2[ZrSi3(O,OH)9] · 2(H2O,F) from the Zhil’naya Valley in the central part of the Khibiny alkaline massif (Kola Peninsula, Russia) is studied by X-ray diffraction (XCalibur-S diffractometer, R = 0.0346): a = 20.100(4), b = 25.673(5), and c = 14.822(3) Å; space group Fdd2, Z = 32, and ρcalcd = 2.76 g/cm3. Fluorine atoms substituting part of H2O molecules in open channels of the crystal structure have been found for the first time in the catapleiite composition by microprobe analysis. The pattern of distribution of Na and Ca atoms over the voids of the mixed anionic framework consisting of Zr-octahedra and three-membered rings of Si-tetrahedra accounts for the pronounced pseudoperiodicity along the a and c axes of the pseudohexagonal unit cell and for the lowering of crystal symmetry to the orthorhombic one. It is shown that part of the hydrogen atoms of water molecules is statistically disordered; their distribution correlates with the pattern of the population of large eight-vertex polyhedra by Na and Ca atoms.  相似文献   

11.
The compound C30H50O (7,8-epoxy-9(87)-abeofriedelane),M r=376.33, orthorhombic, P212121,a=11.819(1) Å,b=14.381(2)Å,c=15.402(2)Å,Z=4,D c=1.083 gm cm–3,R=0.055, for 1643 reflections (withI>2) out of 1743 unique reflections. The three dimensional structure determination is done to characterize the conformation of this series of compounds which has good promise for drug and for rational understanding of the reaction mechanism in the olefin stereochemistry and the structural basis of synthesis of these natural products.  相似文献   

12.
Using X-ray crystal structure analysis of the title compound the positions of all atoms (including all A atoms) were localized in the triclinic unit cell with the parameters a = 14.686 Å, b = 7.700 Å, c = 7.898 Å, α = 122.5°, β = 105.4°, γ = 87.7°, space group P1. The existence of an intramolecular H N … O(1) bridge was inferred, the H-bridge acceptor of which predominantly is the π-electron density of the carbonyl group in agreement with the results of the X-ray crystal structure analysis of p-methyl-phenyl-glyoxyl-acid-p-chloroanilide (HOEHNE , SEIDEL ). Moreover, the existence of H-bridgelike interactions of the two phenyl hydrogen atoms H(6) and H(15) to the carbonyl oxygen O(2) could be proved. These interactions stabilize the conformation of the two phenyl rings in the molecule.  相似文献   

13.
The X-ray crystal structure of glechomafuran (1,10,4,5-diepoxy-7,8-furanogermacrane), a natural product obtained from seeds ofSmyrnium olusatrum L., has been determined in order to establish the correct relative configuration of the molecule. Crystals are monoclinic, space groupP21 witha=6.785(4),b=12.325(9),c=16.390(6) Å,=97.89(4)°, and four molecules in the unit cell. The two epoxides are found to be ,-attached, and the associated methyl groups are positionedsyn to each other. The furan ring is essentially flat, and shows no evidence of any double bond delocalization.  相似文献   

14.
2-S-Methylthiouracil crystallizes in the triclinic space group P with unit cell dimensions a = 5.508(4), b = 7.175(3), c = 8.522(2) Å, = 80.83(2), = 80.43(3), = 76.86(3)°, and Z = 2. The molecule exists in the crystal in the lactam form and is essentially planar. The molecular packing consists of molecules linked in centrosymmetric hydrogen-bonded pairs. The effects of methylation and subsequent metallation on the 2-thiouracil structure are discussed.  相似文献   

15.
The crystal structure of the mineral vyuntspakhite (Y, TR)6{Al2(OH)3[H1.48Si1.88O7][SiO4][SiO3(OH)]}2(a = 5.7551(11) Å, b = 14.752(3) Å, c = 15.906(4) Å, β = 96.046(4)°, sp. gr. P21/n, Z = 2), which had been established earlier in the pseudo-unit cell, is redetermined by X-ray diffraction (R = 0.040, T = 100 K). The redetermination of the structure shows that pronounced pseudotranslation along the axis c′ = c/3 is associated with the fact that Y(TR) atoms are related by a 1/3 translation along the [001] direction. Most of the hydrogen atoms are located. The crystal-chemical function of hydrogen bonds is analyzed. In the unit cell of vyuntspakhite, the cationic layers consisting of edge-sharing (Y,TR) eight-vertex polyhedra alternate along the b axis with mixed anionic layers composed of isolated Si tetrahedra (orthotetrahedra), Si2O7 double-tetrahedra (diortho) groups, Al five-vertex polyhedra, and Al2O8 double-tetrahedra groups linked by shared vertices and through hydrogen bonding.  相似文献   

16.
Single crystals of benzophenone hydrazone (BH) were successfully grown by slow evaporation method at constant temperature, 30 °C. The crystal structure of BH has been determined, and it belongs to the noncentrosymmetric space group P21. The grown crystal has been characterized by FT-IR). The optical transition and the lower cutoff wavelength of the BH have been identified by UV–vis–NIR studies. Thermo gravimetric analysis and differential thermal analysis have been carried out; the BH was found to be thermally stable up to 104 °C. Powder second harmonic generation (SHG) was investigated to explore its nonlinear optical (NLO) properties. The high SHG is due to one dimensional charge transfer between amine and phenyl group. Both the real εr and imaginary εi components of the dielectric constant have been calculated as functions of photon energy.  相似文献   

17.
Nadja Lonnroth  Yuan-Zheng Yue 《Journal of Non》2008,354(12-13):1190-1193
An iron-rich aluminosilicate liquid is studied in different atmospheres by using differential scanning calorimetry. The results show that the oxidation state of iron and the maximum temperature of the scan have an effect on the liquid structure and on the crystallization behavior of the liquid during both cooling and reheating processes. Increase in Fe2+/Fe3+ enhances crystallization and favors formation of a stable crystal structure. The structural order conserved in the liquid is an intrinsic phenomenon, which is not related to the oxidation state of iron.  相似文献   

18.
The crystal structure of a new synthetic potassium gallophosphate K3Ga2(PO4)3 grown from a solution in the melt of a mixture of GaPO4 and K2MoO4 is determined using X-ray diffraction (Bruker Smart diffractometer, 2θmax= 56.6°, R = 0.044 for 2931 reflections, T = 100 K). The main crystal data are as follows: a = 8.661(2) Å, b = 17.002(4) Å, c = 8.386(2) Å, space group Pna21, Z= 4, and ρcalcd = 2.91 g/cm3. The synthesized crystals represent the third phase in the structure type previously established for the K3Al2[(As,P)O4]3 compound. It is shown that the structure consists of a three-dimensional anionic microporous tetrahedral framework of the mixed type, which is formed by PO4 and GaO4 tetrahedra shared by vertices. Large-sized cations K+ occupy channels of the zeolite-like framework. The crystal chemical features of the formation of structure types of compounds with mixed frameworks described by the general formula A 3 + M 2 3+ (TO4)3 (where A = K, Rb, (NH4), Tl; M = Al, Ga, Fe, Sc, Yb; T = P, As) are analyzed.  相似文献   

19.
The crystal and molecular structure determination of the title compound, K–SO2NC2H2,M r=143.21, (1) is part of a series of determinations of N-substituted oxathioamidates. The structure has been refined using single-crystal X-ray diffraction data measured at 295 K [MoK-radiation with =0.71073 Å]. The crystals are orthorhombic, space group Pn2la,Z=8, with cell dimensions:a=11.399(2) Å,b=22.131(2) Å,c=4.021(1) Å,V=1014.5(7) Å3.D calc.=1.875 mg m–3, Dobs=1.600 mg m–3,F(000)=576, =13.14 cm–1. The final agreement factors for 1979 observed reflections [I>3(I)] were:R=0.062 andR w=0.067. The vibrational spectra confirm the geometrical differences between the two thiooxamidate molecules.  相似文献   

20.
The crystal structure of 5-amino-2-nitrobenzoic acid (5A2NB) was determined by the X-ray diffraction method. The 5-amino-2-nitrobenzoic acid crystallizes in the monoclinic P21/c space group with a = 3.898(2) Å, b = 13.531(3) Å, c = 14.301(3) Å, and = 90.83(3)°. The adjacent molecules form a cyclic dimmer by intermolecular hydrogen bonds of type O—HsO with their carboxyl groups. In the crystal structure NH2 group forms a three-center hydrogen bond with oxygen atoms of NO2 group. The IR spectrum and thermal properties of acid are discussed.  相似文献   

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