首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The petrol extract of the rootbark of Milletia Thonningii obtained by column chromatography afforded sixteen different crystalline samples to be isolated. The crystal structures of two of these compounds, O,O‐Dimethylalpinumisoflavone (I) and 5‐O‐Methyl‐4'‐O‐(3‐methyl‐but‐2‐en‐1‐yl)alpinumisoflavone (II) are being reported here. (II) has two independent molecules in the asymmetric unit and differs from (I) in a longer side chain attached to C(15) of the phenyl ring. The structural features of the three molecules in the title compounds are reported and compared. The derivatives, being subject of this article are the first reported crystal structures where the isoflavone fragment is fused to a further six membered ring that results in a tricyclic ring system. The benzopyrone fragments are planar. The dihedral angles between the benzopyrone fragment and the phenyl ring being 55.38(6)° for (I) and 44.75(15)° /44.64(15)° for the respective independent molecules of (II) are within the range of values observed for similar structures.  相似文献   

2.
Crystallization of high temperature self‐flux of system Na2O‐K2O‐TiO2‐P2O5 was investigated at different molar ratios (Na+K)/P = 0.9; 1.0 or 1.2 and Na/K = 1.0 or 2.0 over the temperature range 1000–650°C. The conditions of formation of complex phosphates K0.10Na0.90Ti2(PO4)3 (NASICON‐related) and K0.877Na0.48TiІІІ0.357TiІV1.643(PO4)3 (langbeinite‐related) have been established. The new obtained compounds were investigated using FTIR‐spectroscopy, powder and single crystal X‐ray diffraction and optical microscopy methods. The influence of alkaline metal nature on the structure formation of complex phosphates in the high temperature self‐fluxes is discussed.  相似文献   

3.
4.
Cocrystals of salicylic acid (derived from reaction between aspirin and coformers) with 4,4′dipyridyl, nicotinamide, isonicotinamide, N,N′‐diacetylpiperazine and piperazine have been examined with intent to improve physicochemical properties of antipyretic agent. All of the resulting cocrystals, salicylic acid/4,4′dipyridyl (2:1), salicylic acid/nicotinamide (1:1), salicylic acid/isonicotinamide (1:1), salicylic acid/piperazine (1:0.5) and salicylic acid/ N,N′‐diacetylpiperazine (2:1) (derived from reaction between aspirin and piperazine) are obtained solution cooling/evaporation experiments. The structural analysis has shown that the well‐known COOH ⋅⋅⋅ N heterosynthon was considered the key element in the cocrystals design strategy. The carboxylic acid ⋅⋅⋅ pyridine hydrogen bond is an often used supramolecular synthon. The results from X‐ray Powder Diffraction, DSC, Raman and single‐crystal X‐ray analysis revealed the formation of cocrystal of salicylic acid with several coformers.  相似文献   

5.
The interaction in the molten system Rb2O‐P2O5‐TiO2‐NiO was investigated at different molar ratios Rb/P = 0.5‐1.3, fixed Ti/P = 0.15, Ti/Ni = 1.0 at temperature range 1073–953 K. The conditions of formation of complex phosphates RbTi2(PO4)3, Rb2Ni0.5Ti1.5(PO4)3 and RbNiPO4 have been determined. The new phosphate Rb2Ni0.5Ti1.5(PO4)3 (space group P213, a = 9.9386(2) Å) has been obtained and investigated by the single crystal X‐ray diffraction and FTIR‐spectroscopy. It has langbeinite‐like structure, that is built up from mixed (Ni/Ti)O6‐octahedra and РО4‐tetrahedra. Rubidium atoms are located in closed cavities of 3D‐framework.  相似文献   

6.
A chiral complex of (R)‐2‐((pyridin‐2‐ylmethylene)amino)‐2′‐hydroxy‐1,1′‐binaphthyl ( L ) with hydrated nickel (II) acetate has been synthesized and spectroscopically characterized. The crystal structure of [NiL2(CH3OH)(CH3COO)]CH3COO·CH3OH has been determined by single‐crystal X‐ray diffraction. The complex crystallizes in the orthorhombic space group P 2(1) 2(1) 2(1) with cell constants a = 15.1035 (19), b = 17.836 (2), c = 18.730 (2)Å, α = β = γ = 90.00°, Z = 4. The structure was solved by direct methods and refined to R = 0.0346 (wR2 = 0.0863). The analytical result of the crystal structure indicates that a pair of L ligands chelate to a Ni (II) atom in an asymmetric fashion with one Ni‐N bond being longer than the other, the Ni (II) atom is further coordinated by one methanol molecule and one acetate anion to form a distorted octahedral geometry. In the crystal of the complex, the coordination cation [NiL2(CH3OH)(CH3COO)]+, the uncoordinated methanol molecule and uncoordinated acetate anion are further assembled into one‐dimensional chain structure via intermolecular hydrogen bonds along the a‐axis. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

7.
A new coordination polymer, [Ag3hmt3(μ3 ‐btc)]·5H2O (1) (hmt = hexamethylenetetramine, btc=1,3,5‐benzenetricarboxlic), has been successfully synthesized. Crystal data: P21/a, a = 11.9906(2) Å, b = 17.3689(2) Å, c = 16.96100(10) Å, β = 101.9820(14)°, V = 3455.40(7) Å3, Z = 4, Dc = 2.002 Mg/m3. In the hexagonal structure of Ag‐hmt unit, each Ag‐hmt unit comprises three Ag atoms and three hmt ligands. The μ3 ‐btc ligands bridge adjacent two‐dimensional honeycomb‐like Ag‐hmt layers to form three‐dimensional networks. Structure analysis show that hydrogen bonds play a key role for the stable structure in the compounds. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

8.
The liquidus surface structure and field of LiB3O5 (LBO) primary crystallization have been revealed in Li2O‐B2O3 ‐MoO3 ternary system. The optimization of charge composition and growth conditions results in large volume optical quality LBO single crystals yielding. Crystallographic properties and real defect structure of grown LBO single crystals have been investigated by X‐ray powder diffraction method and X‐ray reflection topography. The volume of the crystals is partly free of any structural imperfections.  相似文献   

9.
Single crystals of (4‐ClC7H6NH3)9[Nd(P6O18)2]·9H2O were synthesized in aqueous solution. This compound crystallizes in a triclinic P1 unit‐cell, with a = 14.898(6), b = 18.049(7), c = 20.695(6)Å, α = 102.04(3), β = 100.49(3), γ = 98.82(3)°, V = 5245(4) Å3 and Z = 2. The crystal structure has been solved and refined to R = 0.043 (Rw = 0.061) for 20420 observed reflections. The atomic arrangement of the title compound can be described as infinite layers built by complex of Neodyme [Nd(P6O18)2] and nine water molecules. The organic cations are located in the space delimited by the successive inorganic layers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

10.
11.
Zirconium‐doped KTiOPO4 (KTP) crystals were grown using a high temperature flux method in the K2O‐P2O5‐TiO2‐ZrF4 system. The dopant content in the single crystals with general composition KTi1‐xZrxOPO4 (where x = 0 – 0.026) strongly depends on zirconium concentration in the homogeneous melts. AES‐ICP method and X‐ray fluorescence analysis were used to determine the composition of the obtained crystals. Phase analyses of the products were performed using the powder XRD. The structures of KTiOPO4 containing different quantities of Zr were refined on the basis of single crystal XRD data. Applying ZrF4 precursor for zirconium injection into the flux allowed growing the zirconium‐doped KTP crystals at 930–750°C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

12.
The structure of the title compound, C15H13N4OCl was determined by single crystal X‐ray diffraction technique. The structure consists of a p‐chlorobenzylamino moiety and triazol and phenyl rings. The title compound crystallizes in the monoclinic space group P21/c with a = 14.368(3), b = 6.255(3), c = 17.631(3) Å, β = 113.24(3)°, Z = 4, V = 1455.8(8) Å3 and Dx = 1.372 gcm‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R=0.0477). The dihedral angle between the triazole moiety and the phenyl ring is 28.8(3)°. The molecular packing is stabilized by N‐H…N and N‐H…O types of inter molecular hydrogen bonds. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

13.
The particularities of the chemical interaction in systems MIPO3‐MIIO(or Mn2O3)‐MICl (MI – Na, K; MII – Mg, Co, Ni, Zn) have been investigated at the temperature 1073 K and molar ratios P/Mx = 1 or 2 and MICl/(MIPO3 + MIIO(or Mn2O3)) = 30. The conditions of formation of complex phosphates MІMIIPO4 and Na4Ni3(PO4)2P2O7 have been found. Influences of the nature of alkali and bivalent metals on the products composition were discussed. The advantages of chloride melts using (synthesis time reduction and temperature reducing) for preparing of complex phosphates were shown. The synthesized compounds have been characterized using the powder X‐ray diffraction, Fourier transform infrared and diffuse reflectance spectroscopies.  相似文献   

14.
The crystal structure of 1‐allyl‐5‐(4‐methylbenzoyl)‐4‐(4‐methylphenyl)pyrimidine‐2(1H)‐thione (C22H20N2OS) has been determined from three dimensional single crystal X‐ray diffraction data. The title compound crystallizes in the monoclinic space group P 21/c, with a = 10.6674(13), b = 10.1077(7), c = 17.9467(19) Å, β = 98.460(9)°, V = 1914.0(3) Å3, Dcalc = 1.251 g cm–3, Z = 4. In the title compound, the allyl group shows positional disorder. Molecules are linked by C‐H···O, C‐H···N and C‐H···S intermolecular interactions forming two‐dimensional network. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

15.
The crystal structure of [Cu(C6H2I3O)2(NH3)2] (CCDC 238896) has been determined by x‐ray diffraction. This monomeric centrosymmetric Cu(II) complex crystallizes in the monoclinic system. The CuO2N2 coordination sphere is trans ‐planar, [Cu–O: 1.943(5) Å and Cu‐N: 1.972(7)] with the fifth and sixth coordination sites occupied by I atoms from the phenoxide ions [Cu–I1: 3.3552(8) Å] to form a tetragonally elongated octahedral structure for CuO2N2I2 coordination. The complex molecules hold together in a one dimensional chain true [100] direction by intermolecular hydrogen bonds. Differantial scanning calorimeter, FTIR and magnetic susceptibility measurements were also performed in order to identify the title complex. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

16.
Adducing structural analogies between the two fused systems, N1, N5‐Dibenzoyltetrahydro‐4‐methyl‐1,5‐benzodiazepin‐2‐one, C24H20N2O3 (DBTBO CCDC 200341) and Tetrahydro‐4‐methyl‐1,5‐benzodiazepin‐2‐one, C10H12 N2O (TBO CCDC 200342) helps to find the pharmacological differences from the view point of variant hetero atom substitutions in the hetero cycle. Both the diazepines crystallized in identical monoclinic space group P21/n with a = 14.1134(1) Å, b = 9.2444(1) Å, c = 16.3812(1) Å; β = 107.11(1)º, V = 2042.7(3) Å3 for DBTBO and a = 9.3363(7) Å, b = 10.4895(8) Å, c = 9.9852(7) Å, β = 91.314(1)º, V = 977.62(1) Å3 for TBO, respectively. The two structures were solved by direct methods and refined by full‐matrix least‐squares procedure to final R‐values of R1 = 0.0575(DBTBO) and R1 = 0.0984(TBO). Structural differences include non‐identical boat conformations of these seven‐membered rings and the different non‐bonding interactions in the benzodiazepine pair.  相似文献   

17.
Conditions of the synthesis, crystal structures, mechanical properties, electrical resistivities and magnetizations of cuprates with the general formula (Cr,Cu)(Sr,La)2(La,A)Cu2O8‐δ where A=Ca or Sr of 1212‐type and (Cr,Cu)Sr2(Y,Ce)2Cu2O10‐δ of 1222‐type were investigated. The compositions of the cuprates and an amount of the impurity phases in the samples were determined. Rietveld refinement of the structure was carried out. It was found that the formal charges of Cu (FCCu) calculated from the electroneutrality of refined phase compositions do not achieve value optimal for the appearence of superconducting phases.  相似文献   

18.
The synthesis of Bi2O3‐Nb2O5 sillenite phase (BNbO) and the solubility of this phase with Bi12TiO20 was investigated by solid‐state reaction synthesis and niobium doped Bi12TiO20 (BTO:Nb) crystals were grown by the Top Seeded Solution Growth (TSSG) technique. The structures of polycrystalline compounds were checked by X‐ray powder diffraction method at room temperature. The correct composition of the sillenite phase stabilized with niobium was determined as Bi12[Nb0.17Bi0.83]O19.7 (BNbO) with unit cell parameter a = 10.261(2) Å. The system BTO‐BNbO is poorly soluble, but niobium doped BTO crystals were grown from the liquid composition 10Bi2O3 : xTiO2 : (1‐x)/2 Nb2O5, with x = 0.95 and 0.90. A niobium concentration limit in the liquid phase is established in order to grow BTO:Nb with good crystalline quality. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

19.
The structure of the title complexes [Cu(AFO)2(H2O)2](ClO4)2.2(AFO).2H2O (AFO = 4,5‐Diazafluoren‐9‐one)has been established by single‐crystal X‐ray diffraction. The complex crystallizes in the triclinic space group P‐1 with cell constants a = 7.659(3) Å, b = 11.066(3) Å, c = 14.203(5) Å, alpha = 75.16(3)°, β = 79.87(3)°, gamma = 85.71(3)°, Z = 1. The structure was solved by direct methods and refined to R1 = 0.0595 (wR2 = 0.1164). The X‐ray analysis reveals that a pair of AFO ligands chelate to a Cu(II) atom in an asymmetric fashion with one Cu‐N bond being much longer than the other, the Cu(II) atom is further coordinated by a pair of aqua ligands to form an elongated octahedral geometry. In the crystal of the complex, the mononuclear complex cations [Cu(AFO)2(H2O)2]2+, uncoordinated AFO molecules, lattice water molecules and perchlorate anions are assembled into 3‐D structure via hydrogen bonds and π‐π stacking interaction.  相似文献   

20.
The compounds 6,7‐dihydro‐2‐methoxy‐4‐(4‐methylphenyl)‐5H ‐benzo[6.7]cyclohepta[1,2‐b ]pyridine‐3‐carbonitrile (compound IIIa) and 4‐(4‐chlorophenyl)‐6,7‐dihydro‐2‐methoxy‐5H ‐benzo[6,7]cyclohepta[1,2‐b ]pyridine‐3‐carbonitrile (compound IIIb) were synthesized and their structures have been determined from three dimensional X‐ray data using direct method and refined by full matrix least squares with anisotropic thermal parameters for non‐hydrogen atoms to conventional R(gt) of 0.036 and 0.038 for the two compounds respectively. For compound (IIIa) the crystals are monoclinic, space group Cc, with a=11.2909 (5) Å, b=17.7755(8) Å, c=9.1437(4) Å and β=95.428(3)°, while the crystals of the second compound (IIIb) are triclinic, space group P1, with a=8.7465(3)Å, b=10.3958(3)Å, c=10.9011(4)Å, α= 108.3870(10)°, β=101.3741(12)°, γ=97.9594(12)°. The molecular structure of the two compounds have nearly the same configuration, where the cyclohepta ring takes the boat shape and the methoxy and the carbonitrile groups are attached at the same position C2 and C8. The difference occurs only at the position C4, where the substituent is methylphenyl for compound (IIIa) and chlorophenyl for the other. The bond lengths, valency angles and the hydrogen bonding were calculated and fully discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号