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1.
Calcium carbonate with hierarchical structure was synthesized in water/organic compound binary soluvent by a chemical solution process within CaCl2/NaCO3 reaction system. Acetone, isopropanol, glycol, tetrahydrofuran were selected as the organic compound. Evolution of the hierarchical structure of CaCO3 was investigated. The as‐prepared products were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). CaCO3 aggregations with spicate hierarchical structure were obtained with a high volume fraction of the organic solvent. Aspect ratio of the hierarchical structure increases to the highest when the volume fraction was 50%. Solvent with low dielectric constant was conducive to the oriented aggregation of the CaCO3 grains. 相似文献
2.
Fangzhi Huang Yuhua Shen Anjian Xie Xiuzhen Zhang Yan Cai Wenting Wu 《Crystal Research and Technology》2009,44(8):818-822
Controlled synthesis of amorphous calcium carbonate (ACC) films was realized by using the multiple templates, which are composed of a self‐assembled film (SAF, insoluble Poly (ε‐caprolactone) film) and a soluble modifier (poly allylamine), as modifiers. The formation of self‐assembled film was analyzed by monitoring the morphologies using atomic force microscopy. Even more noteworthy, using anhydrous ethanol as media, the ACC‐to‐vaterite‐to‐calcite transformation was also investigated, and the obtained products were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. The results demonstrated that organic solvent has profound influence on transformation of amorphous calcium carbonate thin films. In the air of anhydrous ethanol, the controlled synthesis of calcium carbonate films with different morphologies, such as planar films with a few sporadic particles, symmetric rhombohedral crystals, novel crystals with symmetrical terraced convexity formation of calcite, was obtained by the fine‐tuning of induction time. It provides a new and simple method to prepare polymorphic CaCO3 crystal films from the ACC films by controlling the crystallization process (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
Crystallization of calcium carbonate (CaCO3) crystals by a gas‐liquid diffusion method has been carried out in aqueous solution using a double‐hydrophilic block copolymer (DHBC) poly(maleic anhydride)‐b‐poly(acrylic acid) (PMA‐b‐PAA). The as‐prepared products were characterized with X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), selected area electron diffraction (SAED), high‐resolution transmission electron microscopy (HRTEM) and infrared spectroscopic analysis (FT‐IR). Uniform one‐dimensional calcite micro/nanostructures with different morphologies are fabricated through an assembled process. The influence of PMA‐b‐PAA copolymer concentration on the morphology of calcite nano/microwires is investigated, which plays an important role in the morphological control of building blocks composed of one‐dimensional calcite crystals. The possible formation mechanism of one‐dimensional CaCO3 crystals was discussed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
4.
Xiaohui Zhang Fengwen Yan Cunyue Guo Fengbo Li Guochang Chen Zhijun Huang Guoqing Yuan 《Crystal Research and Technology》2011,46(7):664-668
Crystalline calcium carbonate with randomly dispersed porous structure was prepared through co‐ crystallization with calcium peroxide and the following template elimination by a post heating treatment and washing with water. The artificial CaCO3 possess abundant macro‐mesopores structures and high surface area. This approach may open a new general route for the preparation of crystals with high porosity and structure specialty. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
H. Q. Sun D. R. Yuan X. Q. Wang X. F. Cheng C. R. Gong M. Zhou H. Y. Xu X. C. Wei C. N. Luan D. Y. Pan Z. F. Li X. Z. Shi 《Crystal Research and Technology》2005,40(9):882-886
A new metal‐organic coordination nonlinear optical crystal, tri‐allylthiourea zinc chloride (ZnCl2(AT)3, where AT is CH2=CHCH2NHCSNH2, abbreviated as ATZC), is reported. It was synthesized in water and recrystallized in ethanol. For the crystal structure, optical and thermal characterization were determined by elemental analyses, X‐ray diffraction, infrared spectroscopy, differential scanning calorimeter, thermogravimetric analysis, and powder SHG efficiency meansurement. It belongs to the trigonal system, space group R3, with a = 11.0498(4) Å, c = 16.0416(11) Å, z = 3 and V = 1696.24(15) Å3. It exhibits powder SHG efficiency the same order as Urea crystal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
6.
Wenjun Xiao Jie Liu Qin Chen Ying Wu Lizong Dai Tinghua Wu 《Crystal Research and Technology》2011,46(10):1071-1078
Gel–forming fibers (GF fibers) can serve as nucleation sites to prepare calcium carbonate (CaCO3) because they can adsorb large amounts of Ca2+ due to their porous structure. In this paper, mineralization behavior of CaCO3 on GF fibers in ethanol–water mixed solvents without any additives has been investigated. The results showed that some crystals covered the fibers, while others were embedded in fibers. Twin–sphere based vaterite, zonary and rodlike calcite with large aspect ratio could be prepared successfully. The effect of ethanol content inside GF fibers, concentration of Ca2+ and CO32‐, mineralization time, miscibility between alcohol and water, and temperature were studied. Lastly, a possible mineralization mode was suggested. This work could provide a new method to prepare inorganic/polymer hybrid materials. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
7.
The title compound (C19H21F3N2O5) has been determined from three dimensional X‐ray diffraction data. The crystals are monoclinic, a = 7.626(4)Å, b = 17.515(4)Å, c = 15.066(3)Å, β = 101.02(3)°, V = 1975(1)Å3, Z = 4, Dcalc = 1.393g cm‐3, space group P21/c. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R = 0.039). 相似文献
8.
A. Nallini K. Saraboji M. N. Ponnuswamy M. Venkatraj R. Jeyaraman 《Crystal Research and Technology》2005,40(6):622-626
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
9.
The title compound, C22H19N5O2, was prepared and its structure was determined by X‐ray diffraction [CCDC 216074]. The compound crystallizes from ethanol in the orthorhombic system, space group P212121, with unit cell parameters: a =10.048(1) Å, b = 13.935 (2) Å, c =14.607(2) Å, Z =4, and V=2045.3(5) Å3. The crystal structure was solved by direct methods and refined by full‐matrix least‐squares to a final R‐value of 0.0516 with 3621 unique reflections. The central six‐membered ring of the compound has a boat conformation and is not homoaromatic, in which adjacent atoms N1 and N4 deviate from the plane of the ring by 0.4546(33) Å and 0.3786(33) Å, respectively. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
Two polymorphs of silver 5‐(3‐aminophenyl)tetrazolates – α‐ and β‐Ag(amphttz) have been obtained by the reaction of amphttzH with AgNO3 in presence of ammonia either in ambient condition or under the hydrothermal condition, respectively (amphttzH = 5‐(3‐aminophenyl)tetrazole). Both of the two phases of Ag(amphttz) were characterized by elemental analyses, IR spectra and single‐crystal X‐ray diffraction. X‐ray analysis shows α‐, β‐phases crystallize in P ‐1 with a = 8.551 (2) Å, b = 8.720(2) Å, c = 11.173(2) Å, α = 98.15(3)°, β = 90.95(3)°, γ = 95.45(3)° and C 2/c with a = 13.542(3) Å, b = 10.135(2) Å, c = 12.610(3) Å, β = 113.58(3)°, respectively. The two polymorphs exhibit different 3D structures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
11.
Hua Tang Qiong Wu Xiaofei Yang Bin Yang Changsheng Li 《Crystal Research and Technology》2010,45(10):1094-1098
Large‐scale star‐like PbWO4 hierarchical architectures were controllably synthesized by a facile surfactant‐assisted technology under mild conditions in the presence of a mixed solvent of ethylene glycol and water. The morphology, structure, and phase composition of PbWO4 architectures were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), field emission transmission electron microscopy (FE‐TEM), and nitrogen adsorption‐desorption isotherms. The possible formation mechanism of the star‐like PbWO4 architectures (initial nucleating stage and a subsequent self‐assembly stage) was proposed based on the observations from a time‐dependent morphology evolution process, which may pave the way to shape‐controlled synthesis of inorganic nanocrystals with the complex structures. This route provides a facile strategy to fabricate complex hierarchical PbWO4 structures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
12.
Rajnikant V.K. Gupta M.B. Deshmukh B. Varghese Dinesh 《Crystal Research and Technology》2001,36(12):1451-1456
The crystal structure of methyl‐3, 4‐dihydro‐3‐(p‐methylphenyl)‐4‐oxo‐2‐quinazolinyl thiopropionate (C19H18N2O3S) has been determined by X‐ray diffraction methods. The compound crystallizes in the triclinic space group P with unit cell parameters: a = 9.094(2), b = 9.428(3), c = 10.612(3) Å, α = 94.55(3), β = 95.44(2), γ = 106.75(3)° and Z = 2. The structure has been refined to an R‐value of 0.054 for 2533 observed reflections [Fo > 4σ(Fo)]. The quinazoline moiety and the methyl substituted phenyl ring is almost planar. The dihedral angle between these two moieties is 84.96(8)° . The crystal structure is stabilized by an intermolecular C‐H … O interaction. 相似文献
13.
S.
ztürk S. Is�k H.‐K. Fun E. Agar S. Sasmaz O. Büyükgüngr 《Crystal Research and Technology》2000,35(9):1125-1130
The crystal structure of the title compound, C25H26Br2N2O4S2 was determined by single crystal X‐ray diffraction technique. The crystals are monoclinic, space group C 2/c, with a=20.7142(2) Å b=11.7910(2) Å, c= 10.6735(3) Å, β=98.549(2)°, V=2577.94(9) Å3, Z=4. The structure was solved by direct methods and refined by least‐squares methods to a final R=0.046 for 1866 observed reflections with I>2sigma(I). The title compound, displays disordered geometry around the C1 atom located almost on twofold axis. The nine‐membered heterocylic ring is close to the half‐chair conformation. The dihedral angle between phenyl rings is 34.2(1)°. 相似文献
14.
The title compound (C14H10N2O2Cl2) crystallizes in the monoclinic space group P21/a with a=10.042(1) Å, b=10.317(1) Å, c=13.877(2) Å, β=97.36(2)°, V=1425.8(3) Å3, Z=4, Dx=1.44 g.cm‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R = 0.0457). The title molecule consists of 3,4‐dichlorophenylamino and 2‐phenyl‐1,2‐ethanedione‐1‐oxime groups. The intermolecular O‐H…N and N‐H…O hydrogen bonds [O…N 2.760(6) and 3.087(5) Å] are highly effective in forming the polymeric chains. The oxime group has an E configuration. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
Complex CaCO3 superstructure can be easily synthesized by using poly (sodium 4‐styrenesulfonate) (PSSS) as a structure directing agent to direct the controlled precipitation of calcium carbonate from aqueous solution. The products were characterized by scanning electron microscopy (SEM), and powder X‐ray diffraction (XRD) analysis. The results revealed that the morphology of the products changed significantly with the increasing of the concentration of PSSS in solution, from rhombohedral particles to plate‐packed aggregates to spheres with smooth surface, to sponge‐like spheres and finally to complex spherical superstructure consisted of plate‐like sub‐units. We hypothesize that the observed sequential changes in morphology of CaCO3 particles with added PSSS concentration may be due to the influence of PSSS on nucleation, growth and aggregation of CaCO3 crystals. The formation mechanisms of CaCO3 crystals with different morphologies were discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
M. Nilofarnissa S. Banumathi D. Velmurugan N. Ramasubbu 《Crystal Research and Technology》2000,35(3):333-341
The crystal structure of the synthetic peptide Boc — Aib — Ile ‐ OMe (C16 H3 0 N2 O5 ) has been determined from three‐dimensional X — ray diffraction data. The peptide crystallizes in triclinic space group P1 with a = 9.570(9), b = 10.261(7), c = 10.610(2) Å , α = 101.9(0), β = 91.7(0), γ = 98.6(0)° V = 1006.1(12) Å3, Z = 2, Dcalc = 1.09 Mg m‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method to an R value of 0.072 (λ = 1.5418Å). The conformation of Aib residue in molecule A is αL and in molecule B is αR. The Ile residue in molecule A adopts folded conformation, while in molecule B it is in the extended region. The peptide units are trans and show significant deviations from planarity. 相似文献
17.
V. T. Yilmaz E. Agar K. Guven B. Kahveci S. Sasmaz 《Crystal Research and Technology》2004,39(9):811-814
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
18.
Feng‐Wen Yan Shu‐Feng Zhang Cun‐Yue Guo Xiao‐Hui Zhang Guo‐Chang Chen Fang Yan Guo‐Qing Yuan 《Crystal Research and Technology》2009,44(7):725-728
Control over crystal morphology of calcium carbonate (CaCO3) was investigated by simply changing the stirring speeds in the process of CaCO3 formation. Scanning electron microscopy (SEM) and powder X‐ray diffraction (XRD) measurements explore the morphology evolution of CaCO3 at varying stirring speeds. As the stirring speeds increase, rhombohedral calcite, spherical vaterite, and monoclinic crystal with coexistence of calcite phase and vaterite phase were formed, suggesting a facile control over calcium carbonate crystallization in constructing crystals with desired morphology. Moreover, almost pure vaterite spherical particles of narrow particle size distribution were formed at optimum stirring speed. Finally, also elucidated in this work is the mechanism investigation into the construction of various crystal forms via this simple route. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
S. M. Malathy Sony N. Sukumar M. N. Ponnuswamy R. Jayakumar 《Crystal Research and Technology》2004,39(4):368-374
The dipeptide Boc‐Lys(OBzl)‐Ile crystallizes in monoclinic space group P21 with cell parameters a = 5.003(1), b = 19.199(3), c = 15.270(2)Å, β =93.42(1)°, V = 1464.1(3)Å3, Z = 2, Dcal = 1.117 Mg/m3 at T = 293 K. The structure was solved by direct methods and refined by full‐matrix least‐squares procedure to a final R = 0.096 and wR = 0.101 using 1379 reflections. The peptide unit is in trans conformation and the molecule takes up an extended conformation. In the lysine side chain, delocalization of electrons and pseudo peptide bond formation is observed at the interaction site of benzyloxycarbonyl group. Both N‐H…O and main chain C‐H…O hydrogen bonds stabilize the molecules in the unit cell in a parallel β‐sheet fashion. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
20.
L. Govindasamy V. Rajakannan D. Velmurugan A. K. Mohanakrishnan P. C. Srinivasan 《Crystal Research and Technology》2003,38(2):182-192
The crystal structure of 3‐Hydroxy methyl 4,6‐dimethoxy‐9‐phenylsulfonyl‐carbazole. (C21H19NO5S) has been determined [CCDC 194425]. The compound crystallizes from methanol in the monoclinic system, space group I2/c, with unit cell parameters: a = 20.498(2), b = 9.258(2), c = 21.866(3)Å, β = 116.450(10)°, Z = 8, V = 3715.2(10)Å3. The crystal structure was solved by direct methods and refined by full‐matrix least squares to a final R‐value of 0.050 with 3508 unique reflections. The planar carbazole ring fragment is inclined at an angle of 79.9(1)° to the phenylsulfonyl group. The sum of the angle about N is 351.6(2)°. The atoms linked to the central hexavalent S atom are arranged in a tetrahedral configuration with the larger deviations in the O‐SO angles [O1‐S‐O2 = 119.7(2)°] and the O1‐S‐N and O2‐S‐N angles [106.1(2) and 106.9(1)°, respectively]. 相似文献