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1.
A complex investigation of the domain structure and dielectric properties of triglycine sulfate (TGS) crystals containing profile layers doped with D,L-α-alanine (DLATGS) and L-α-alanine (LATGS) impurities is carried out. The images of the DLATGS and LATGS layers and ferroelectric domains are obtained by piezoelectric force microscopy; the parameters of the domain structure and the degree of unipolarity are determined. It is established that DLATGS layers are multidomain and LATGS stripes are mainly single-domain. The experimental data on the macroscopic dielectric properties of the crystals are compared with the results of a microscopic analysis of the domain structure.  相似文献   

2.
The molecular structure of [(tBu)2Al(-OC6H5-2-Me)]2 has been determined. Both the ortho-tolyl methyl groups are oriented towards Al(2). The intramolecular steric interaction between the ortho-methyl groups and the tert-butyl ligands results in the geometry about the bridging oxygen being significantly distorted while the geometries about the aluminum centers show a distortion from tetrahedral that is less than the sterically less hindered [(tBu)2Al(-OPh)]2. Crystal data: group C2/c, a = 13.733(3) Å, b = 15.135(3) Å, c = 15.420(3) Å, = 104.24(3), V = 3106(1) Å3, Z = 4, R = 0. 0612, wR2 = 0.1787.  相似文献   

3.
Abstract N-(2,6-difluorobenzoyl)-N′-[5-(pyrid-4-yl)-1,3,4-thiadiazol-2-yl]urea, 3, has been synthesized by reaction of 2-amino-5-(pyrid-4-yl)-1,3,4-thiadiazole with 2,6-difluorobenzoyl isocyanate, and its structure was characterized with X-ray crystallographic, NMR, MS and IR techniques. It crystallizes in the triclinic space group P − 1, with a = 7.0821(9) ?, b = 9.4896(13) ?, c = 11.6594(15) ?, α = 82.311(2)°, β = 82.328(2)°, and γ = 87.641(2)°. In the title compound, the urea scaffold in each molecule is essentially planar due to the presence of intramolecular N–H···O hydrogen bond. The molecules are linked by intermolecular complementary N–H···O hydrogen bonds into centrosymmetric R 22(8) dimers. Intermolecular ππ stacking interactions are also present. The preliminary bioassay shows that the title compound exhibits excellent fungicidal activities against Rhizoctonia solani, Botrytis cinerea and Dothiorella gregaria. Index Abstract N-(2,6-difluorobenzoyl)-N′-[5-(pyrid-4-yl)-1,3,4-thiadiazol-2-yl]urea has been synthesized and characterized with X-ray crystallographic, NMR, MS and IR techniques. The preliminary bioassay shows that the title compound exhibits excellent fungicidal activities.   相似文献   

4.
The crystal and molecular structures of a cyclic β-triketone, namely, trans-2-(4′-dimethylaminobenzylideneacetyl)-5,5-dimethylcyclohexane-1,3-dione (I), are determined using X-ray diffraction analysis. It is established that the compound in the crystalline state exists in a diketo-enol form stabilized by intramolecular hydrogen bonds. The specific features of the structure and the physicochemical and fluorescence properties of the compound are discussed.  相似文献   

5.
Molecular and crystal structure of N-(6-methoxybenzothiazol-2-yl)-1-(4-fluorophenyl)-O,O-dipropyl-α-aminophosphonate, C21H26FN2O4PS, have been determined by single-crystal X-ray diffraction study. The title compound is tetragonal, with a = 21.35(3) Å, c = 20.16(5) Å, Z = 16, D x = 1.308 Mg/m3, μ(MoKα) = 0.247 mm?1, and space group is I41/a. The structure was solved by direct method and refined to a final R = 0.0687 for 2370 reflections with I > 2σ(I). The compound shows a fully delocalized benzothiazole system with a sp2 hybridization of the N(2). There is a strong intermolecular hydrogen bond between P=O and NH. The crystal structure is stabilized by a strong intermolecular N–H?sO hydrogen bond.  相似文献   

6.

Abstract  

The hydrazone compounds, N′-(5-chloro-2-hydroxybenzylidene)-4-dimethylaminobenzohydrazide (1) and N′-(2,4-dichlorobenzylidene)-4-dimethylaminobenzohydrazide (2), have been synthesized by the condensation reaction of equimolar quantities of 4-dimethylaminobenzohydrazide with 5-chlorosalicylaldehyde and 2,4-dichlorobenzaldehyde, respectively, in methanol. The compounds were characterized by elemental analysis, IR, 1HNMR spectra, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 35.014(3) ?, b = 10.407(2) ?, c = 18.505(2) ?, β = 112.046(2)°, V = 6250.0(15) Ǻ3, Z = 16, R 1 = 0.0624, and wR 2 = 0.1187. Compound 2 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.625(2) ?, b = 12.688(3) ?, c = 13.005(2) ?, α = 101.271(2)°, β = 112.945(1)°, γ = 104.966(2)°, V = 1747.6(6) Ǻ3, Z = 2, R 1 = 0.0523, and wR 2 = 0.1138. In the asymmetric unit of each compound, there exists two hydrazone molecules linking together by an N–H⋯O hydrogen bond. Furthermore, compound (2) contains one methanol molecule and one water molecule of crystallization.  相似文献   

7.
The hydrolysis product of neotame, N-(3,3-dimethylbutyl)-l--aspartyl-l-phenylalanine (DMBAP), was crystallized from water as an anhydrate with a melting point at 197C with decomposition. Its crystal structure was determined by single crystal X-ray diffractometry. The crystal is orthorhombic with space group P212_121 with Z=4 and one molecule per asymmetric unit. The cell constants are a=5.520 (2) Å, $b=10.608$ (5) Å and c= 31.92 (2) Å. The 13C solid-state nuclear magnetic resonance spectrum of DMBAP is compared with those of neotame monohydrate and neotame methanol solvate.  相似文献   

8.

Abstract  

Two of N′-N′-(4,6-disubstituted-pyrimidin-2-yl)-N-[2-(2,4-dichlorophenoxypropionyl)]thiourea (4a-4b) had been synthesized and their crystal structures had been determined by X-ray diffraction method. 4a crystallizes in the triclinic space group P-1, with a = 8.053(12) ?, α = 102.84(2)°, b = 10.541(16) ?, β = 106.99(2)°, c = 12.461(19) ?, γ = 94.615(19)°, and D c  = 1.470 mg/m3 for Z = 2. 4b crystallizes in the triclinic space group P-1, with a = 7.939(5) ?, α = 105.302(10)°, b = 10.183(7) ?, β = 105.729(9)°, c = 12.764(9) ?, γ = 90.698(11)°, and D c  = 1.517 mg/m3 for Z = 2.  相似文献   

9.
Abstract  A new isomer of [Ni(tet-a)]2+ (assigned as γ-isomer) (tet-a = C-meso-5,5,7,12,12,14−hexamethyl-1,4,8,11-tetraazacyclotetradecane), which is found in the complex of trans-γ-[Ni(tet-a)(NCS)2], has been isolated from the reaction of β-[Ni(tet-a)](ClO4)2 with NaSCN in a mixture of MeOH–H2O (1:1, v/v) solution and characterized by X-ray crystallography. The complex crystallizes in orthorhombic Pca2(1) space group with the crystal cell parameters of a = 12.5787(10) ?, b = 11.6834(10) ?, c = 15.4019(12) ?, V = 2263.5(3) ?3, and Z = 4. The crystal structure shows that the complex is noncentrosymmetric. The conformations of the six-asymmetric centers are assigned as 1R,4R,8S,11S,7R,14S or 1S,4S,8R,11R,7S,14R (Trans-III). The coordination polyhedron around the nickel atom is axially elongated octahedron with an N6 chromophore. The association of the complex units through N(3)–H···S(1) (2.665 ?) hydrogen bonding interactions leads one-dimensional hydrogen bonded network along c-axis. Index Abstract  A new isomer of Ni(tet-a)2+, which is assigned as γ-isomer, in the complex of trans-γ-[Ni(tet-a)(NCS)2] has been synthesized, isolated and characterized by X-ray crystallography. The complex units form a one-dimensional self-assembly hydrogen bonded network.   相似文献   

10.
Tris-(-(3-methyl-5-trifluoromethylpyrazolato)-N:N)triangulo-trigold(I), (3,5-tfmpz)3 Au3, has been synthesized and exhibits a planar nine-member ring containing a central gold triangle with an average intramolecular Au–Au distance of 3.3455(8) Å. The complex crystallizes in the monoclinic space group Cc with a = 12.998(2) Å, b = 22.910 (3) Å, c = 7.217(1) Å, and = 104.781(1). The solid-state structure consists of sheets of (3,5-tfmpz)3Au3 units stacked in an offset fashion along the c axis such that one gold atom in each Au3 unit (Au1) lies approximately over the midpoint of the Au1–Au3 edge of the triangle in the layer below it. The intermolecular Au–Au distances are between 3.880(1) and 4.023(1) Å, which are too long for there to be significant intertrimer bonding interaction suggesting that any supramolecular organization may be due to hydrogen-fluorine and fluorine-fluorine interactions between the molecules. The complex exhibits excitation-dependent emission at room temperature in the solid state. The structured higher energy emission (em = 468, 517, and 556(sh) nm) is believed to be a ligand-centered * transition with a lower energy unstructured emission (em = 658 nm) assigned to the classical Au–Au excited state transition.  相似文献   

11.
The conditions and the mechanism of the formation of a ferromagnetic phase in a Ti1-xCo x O2-δ oxide semiconductor are studied. It is found that the ferromagnetism manifests itself at room temperature in the films of Co-doped TiO2-δ oxide deposited on SrTiO3 (100) substrates only within a limited range of charge carrier densities: 2 × 1018?3 × 1022 cm?3. The minimum concentration of charge carriers corresponding to the formation of the ferromagnetic phase increases with a decrease in the cobalt content in the material under study. The ferromagnetism in Ti1-xCo x O2-δ thin films can be attributed to Co-enriched clusters with above critical sizes.  相似文献   

12.

Abstract  

Treatment of [Mo(CO)3(NCMe)3] with bis(diphenylphosphino)methane (dppm) and triphenylphosphine (PPh3) at 50 °C afforded mer-[Mo(CO)3(PPh3)(κ 2-dppm)] (1) in 55% yield which has been characterized by single crystal X-ray diffraction studies and spectroscopic measurements. Compound 1 crystallizes in the triclinic space group P−1 with a = 10.3449(6), b = 11.1570(6), c = 17.8961(10) ?, β = 80.8400(10)°, Z = 2 and V = 1959.8(2) ?3.  相似文献   

13.
The title compound was prepared from the reaction of (n-Bu4N)[ReOCl4] with a twofold molar excess of 2-(hydroxymethyl)pyridine in benzene. It has a distorted octahedral coordination geometry, and it crystallizes in the monoclinic space group P21/n, with cell dimensions a = 14.4545(4), b = 7.0168(2), c = 14.5269(4) Å, = 116.995(1), V = 1312.85(7) Å3, and Z = 4.  相似文献   

14.
Treatment of the labile cluster Os3(CO)10(CH3CN)2 with morpholine in benzene at 60°C afforded Os3(CO)10(μ-η2-NC4H6O)(μ-H) (1). Decarbonylation of 1 at 128°C gave Os3(CO)932-NC4H6O)(μ-H) (2), which reacts with PPh3 at ambient temperature to give an addition product Os3(CO)9(μ-η2-NC4H6O)(PPh3)(μ-H) (3). Compound 1 reacted with PPh3 at 98°C to give the substitution product 4 which is an isomer of 3. The reaction of Ru3(CO)12 with morpholine in the presence of Me3NO in refluxing benzene at 80°C afforded Ru3(CO)932-NC4H6O)(μ-H) (5). Compounds 15 have been characterized by elemental analysis, infrared, 1H NMR, and mass spectroscopic data. The molecular structure of 1 has been determined by single crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group P2/c with a = 29.598(8) Å, b = 9.202(2) Å, c = 14.496(4) Å, β = 93.19(3)°, Z = 8, and V = 3942(2) Å3. Compound 1 consists of an isosceles triangle of osmium atoms with one elongated Os–Os edge, which is bridged by the hydride and the morpholine ligand.  相似文献   

15.

Abstract  

A new bishydrazone compound, N,N′-di[(E)-1-(2-hydoxyphenyl)methylidene]-2,6-naphthalenedicarbohydrazide (1), has been prepared by condensation reaction of 2,6-naphthalenedicarbohydrazide with salicylaldehyde in ethanol, and characterized by elemental analysis, FT-IR, 1H- and 13C-NMR, ESI–MS and single-crystal X-ray diffraction analysis. The crystal of 1·2DMF belongs to monoclinic, space group P2(1)/n with a = 10.454(1), b = 7.711(1), c = 18.801(2) ?, β = 93.364(1)°, V = 1512.9(3) ?3, Z = 2, D c  = 1.314 g cm−3, μ = 0.093 mm−1, F(000) = 632, Mr = 598.65, the final R 1 = 0.0861 and wR 2 = 0.2279 for 7243 observed reflections with I > 2σ(I). The structural analysis reveals that compound 1·2DMF contains one N,N′-di[(E)-1-(2-hydoxyphenyl)methylidene]-2,6-naphthalenedicarbohydrazide molecule and two N,N-dimethylformamide solvent molecules. A 2D supramolecular structure of 1·2DMF was constructed by multiple intermolecular N–H···O and C–H···O hydrogen bonds.  相似文献   

16.

Abstract  

Hydrothermal synthesis and the structural characterization of V(IV) complex of 2-pyrazinecarboxylate (pzc), is reported. The vanadium is in a distorted octahedral environment. Pairs of pyrazine-2-carboxylate ligands are always cis to each other. The pzc ligands do not link adjacent vanadium atom directly. The remainder of the three-dimensional network is completed by intense hydrogen bonding of uncoordinated water molecules to aqua and pzc ligands. Cis-[VIVO(pzc)2(H2O)]·2H2O, 1, was characterized by means of elemental analysis (CHNS), TGA, FT-IR, manganometric titration, bond valance sum calculations and single crystal X-ray diffraction methods. Crystal data for 1: monoclinic space group P2 1 /c and unit-cell parameters are a = 9.1142(5), b = 16.5822(10), c = 12.8936(7) ?, β = 131.625(3)° and Z = 4. To the best of our knowledge, cis-[VIVO(pzc)2(H2O)] is reported without single crystal structure by Eugenio Garribba and his colleagues in year 2006. Herein we complete full characterization of the title complex with single crystal structure and also 1 will be the first reported example of solid vanadium complex of 2-pyrazinecarboxylates involving intense hydrogen bonding.  相似文献   

17.
Abstract  Diethyl-2,2′-bipyridine-3,3′-dicarboxylate (3 or L) reacts with RuCl3 · 3H2O to give cis-(Cl)-[Ru(L)2Cl2] · H2O (4) and structure of the complex was determined by spectral (IR, 1H-NMR), and mass spectroscopic data, elemental analyses and X-ray crystallography. The structure is solved in triclinic, space group p-1 with a = 10.658 (2), b = 12.446 (3), c = 14.186 (5) ?, α = 104.856 (3), β = 108.704 (3), γ = 94.973 (2)°, V = 1693.2 (8) ?3, Z = 2 with final R = 0.012. The geometry of the complex is shown to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes with Ru–N distance as 2.021 (2)−2.071 (3) ?. The cis-position is occupied by two chloride atoms with Ru–Cl distance as 2.4156 (12) and 2.4167 (13) ?. The trans-axial Cl2–Ru1–N and Cl1–Ru1–N4 angles are respectively, 172.42 (7) and 174.12 (7)°. A weak hydrogen bonding is observed between the two chlorides and hydrogens of neighbouring molecule [C–H···Cl distance as 2.72, 2.77 (4) ?]. A second type of weak hydrogen bonding is also observed between the oxygens of carboxylate groups and hydrogens of a neighbouring molecule [C–H···O distance as 2.53, 2.56 and 2.34 (4) ?]. Graphical Abstract  The structure of anti-tubercular precursor complexes, cis-(chloro)-[N,N′-bis-(diethyl-2,2′-bipyridine-3,3′-dicarboxylate)]ruthenium(II) monohydrate is solved by single crystal X-ray diffraction analysis which reveals geometry of the complex to be a distorted octahedral with four nitrogens of two 2,2′-bipyridyl ligands in two different planes. The cis-position is occupied by two chloride atoms.   相似文献   

18.
Abstract  20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol (I) has been isolated as a metabolite of ginseng saponins by Paecilomyces bainier. The crystal structure of (I) was also investigated by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group P21, with a = 15.99 2 (3) ?, b = 11.960 (19) ?, c = 20.127 (3) ?, β = 101.85 (4)°, and V = 3767.5 (11) ?3, Z = 4, R int = 0.1129, ωR(F 2) = 0.1749, F(000) = 1,448. The title compound is a dammarane-type triterpenoid, and the four rings of this compound connect with each other in trans characteristics,with the three-six-membered rings in chair conformation and the five-membered ring adopting envelope one. A β-d-glucopyranosyl group and a 2-methyl-2-pentenyl group connect to C20 of S configuration. The space symmetrical motif is adopted and each packing unit-cell contains two symmetrical compound (I) molecules and four H2O molecules. The hydrogen-bonding (both intra- and inter-molecular) interactions play a major role in this structural association. Index Abstract  In the present paper, the single-crystal structure of 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol was determined by X-ray analysis   相似文献   

19.
Abstract By inclusion complexation with the chiral host compound (R)-(+)-4,4′,6,6′-tetrachloro-2,2′-bis(hydroxydiphenylmethyl)-1,1′-biphenyl, racemic 3-methyl-2-pyrrolidinone was resolved and its (S)-(−)-enantiomer was isolated as a 1:1 inclusion complex, which crystallises in the orthorhombic crystal system in the space group P212121 (a = 14.1163(2) ?, b = 14.7140(3) ?, c = 17.2025(3) ?). By the inclusion complexation, the keto–enol equilibrium of the guest was frozen and the keto-form was isolated in a pure form. By X-ray structural study of the complex, the guest molecule included was elucidated to be the keto-form and its absolute configuration was determined to be (S). Index Abstract By inclusion complexation with (R)-(+)-4,4′,6,6′-tetrachloro-2,2′-bis (hydroxydiphenylmethyl)-biphenyl, racemic 3-methyl-2-pyrrolidinone was resolved and its (S)-(−)-enantiomer isolated and in addition the keto–enol equilibrium of the guest was frozen and the keto-form isolated. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

20.
Abstract  The N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide 6 was synthesized from aryl triazole acids and its structure is established by MS, IR, and 1H NMR spectral data. Compound 6, C22H22N8O4, Mr = 462.48, crystallizes in the monoclinic space group P2(1)/c with unit cell parameters a = 15.3451(8), b = 8.6486(4), c = 16.8502(9) ?, α = 90.00, β = 95.731(2), γ = 90.00o, V = 2225.1(2) ?3, Z = 4, and Dx = 1.381 mg m−3. The final R was 0.0450. The four aromatic rings are close to linear because of N···H–N hydrogen bonds. Index Abstract  Synthesis and crystal structures of N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide Heng-Shan Dong, Yan-Fei, Wang, Hong-Ru Dong, Bin, Wang, Bin Quan N,N′-Bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide was synthesized.   相似文献   

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