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1.
TiO2 nanotube(TiNT) arrays were deposited on boron-doped diamond films by a liquid-phase deposition method with ZnO nanorod arrays as the template.The different morphologies of TiNTs have been obtained by controlling the morphology of ZnO template.The X-ray diffraction and energy-dispersive X-ray analysis show that the ZnO nanorod array template has been removed in the TiNTs formation process.The crystalline quality of the TiNTs is improved by increasing the annealing temperature.The band gap of the TiNTs is about 3.25 eV estimated by the UV-Vis absorption spectroscopy,which is close to the value of bulk TiO2.In the photoluminescence spectrum,a broad visible emission in a range of ca.550-750 nm appears due to the surface oxygen vacancies and defects.  相似文献   

2.
陈水生  乔瑞  杨松  凡素华 《结构化学》2013,(9):1415-1421
Two new complexes,[Zn(L1)2(SCN)2]·H2O(1,L1 = 3,5-dimethyl-4-p-tolyl-4H1,2,4-triazole and [Cd3(L2)6(SCN)6](2,L2 = 3,5-dimethyl-4-phenyl-4H-1,2,4-triazole),have been hydrothermally prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental analysis and PXRD.Complex 1 crystallizes in monoclinic,space group P21 /n with a = 11.246(13),b = 9.640(11),c = 26.13(3),β = 100.97(3),V = 1108.5(3) 3,Z = 4,C24 H28 N8 OS2 Zn,Mr = 572.02,Dc = 1.366 g/cm3,μ = 1.065 mm-1,S = 0.992,F(000) = 1184,the final R = 0.0602 and wR = 0.1700 for 2925 observed reflections(I 2σ(I)).Complex 2 crystallizes in triclinic,space group P1 with a = 11.6669(3),b = 12.0957(2),c = 14.3674(3),α = 105.380(3),β = 91.020(2),γ = 92.4100(10)o,V = 1952.30(7)3,Z = 1,C66H66N24S6Cd3,Mr = 1725.08,Dc = 1.467 g/cm3,μ = 1.025 mm-1,S = 1.037,F(000) = 870,the final R = 0.0336 and wR = 0.0946 for 7819 observed reflections(I 2σ(I)).In the title complexes,complex 1 is a mononuclear molecule where the centre Zn(II) coordinates to two 3,4,5-substituted 1,2,4-triazole ligands(L1) and two terminal SCN-anions in a tetrahedral environment while six-coordinated centre Cd(II) atoms with octahedral geometry in complex 2 are bridged by virtue of substituted 1,2,4-triazole(L2) in N1,N2-bridging mode and μ2-N,N-SCN-anions into a trinuclear molecule.  相似文献   

3.
Three isomeric metal-organic frameworks,[Cd2(X)(btc)(DMA)3]n(X = Cl(1),Br(2),I(3),H3btc =1,3,5-benzenetricarboxylic acid and DMA = N,Nˊ-dimethylacetamide),have been synthesized and characterized by elemental analysis,infrared spectra(IR),thermogravimetric(TG) analyses and single-crystal X-ray diffraction.Single-crystal X-ray analysis reveals that compounds 1–3 crystallize in the orthorhombic P212121 space group,and feature a three-dimensional(3D) extended framework containing dinuclear [Cd2(COO)3] units as the secondary building units(SBUs).Topological analysis reveals that compounds 1–3 can be simplified into a 3-connected srs topological network.  相似文献   

4.
We reported the environmental benign synthesis of chalcones,2-pyrazolines and cyclohexanones under microwave irradiation.Chalcones were obtained by the condensation of each of 2-hydroxyacetophenone derivatives with a-naphthaldehyde under microwave irradiation.The condensation reactions of each of synthesized chalcones with phenyl hydrazine under microwave irradiation in the presence of dry acetic acid as a cyclizing agent gave 2-pyrazolines.Also,the new cyclohexenone derivatives,valuable intermediates to synthesize fused heterocycles,have been prepared by the cyclocondensation of each of hydroxychalcones with ethyl acetoacetate.The structures of the synthesized compounds were elucidated by infrared(IR) spectrometry,nuclear magnetic resonance(NMR),mass spectrometry(MS) and elmental analysis.The results indicate that unlike classical heating,microwave irradiation results in higher yields with shorter and cleaner reactions.The synthesized compounds were screened for antimicrobial activity against Staphylococcus aureus,Escherichia coli,Candida Albicans and Aspergillus niger.We clarified the effects of different substituents in the tested compounds on the obtaind antibacterial activities and antifungal activities.  相似文献   

5.
A cocrystal based on 1,3-di(4-pyridyl)propane and 3-((4′-carboxybenzyl)oxy)benzoic acid,C13H14N2·C15H12O5,has been synthesized and characterized by single-crystal X-ray diffraction.The compound crystallizes in monoclinic,space group P21 /c with a = 11.639(4),b = 9.808(3),c = 20.854(6),β = 91.242(7)°,V = 2380.0(13)3,C28H26N2O5,Mr = 470.51,Dc = 1.313 g/cm3,μ(MoKα) = 0.091 mm-1,F(000) = 992,Z = 4,the final R = 0.0677 and wR = 0.1477 for 4175 observed reflections(I > 2σ(I)).Intermolecular N H···O hydrogen bonds link two kinds of components into a one-dimensional chain in [10-1] direction and adjacent chains are further arranged into a two-dimensional network by π···π and C H···π interactions.Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that the close contacts are mainly focused on weak interactions.The theoretical investigations with HF/6-31G(d) method were performed,and its stability,frontier molecular orbital composition and Mulliken charge distribution were also discussed.  相似文献   

6.
Highly ordered mesoporous NiMoO4material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4with the coexistence of α-NiMoO4and β-NiMoO4showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoO4was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogenation of propane in comparison with bulk NiMoO4.  相似文献   

7.
Meysam Najafi 《结构化学》2013,(9):1374-1386
ABSTRACT The antioxidant activity of ortho and meta substituted Enterolactone derivatives has been investigated in the gas phase and water.The reaction enthalpies of antioxidant activity of the studied derivatives have been calculated and compared with the corresponding values of Enterolactone.Results show that EWG substituents increase the BDE and IP,while the EDG ones rise in the PA.The Enterolactone derivatives with the lowest BDE,IP and PA values were identified as the compounds with high antioxidant activity.Results show that the substituents in the ortho position have high potential for the synthesis of novel Enterolactone derivatives.Results show that Enterolactone derivatives can processes their protective role via HAT and SPLET mechanism in gas phase and solvent,respectively.The calculated reaction enthalpies of the substituted Enterolactones have linear dependence with Hammett constants and EHOMO that can be utilized in the selection of suitable substituents for the synthesis of novel antioxidants based on Enterolactone.  相似文献   

8.
An enhanced active and selective catalyst consisting of ruthenium supported on dealuminated HY zeolite has been prepared by a wet impregnation method. It was found that BET surface area of Ru/HY catalysts significantly increases after HCl treatment. This treatment also increases the concentration of strong acid sites in the catalyst. The hydrogenolysis of glycerol over 5 wt% Ru/HY catalyst was investigated at 190-220 ℃, an initial H2pressure of 3-6 MPa, and in 20 wt% glycerol aqueous solution. The results indicate that HCl treated Ru/HY catalyst shows higher activity compared with the untreated Ru/HY catalyst, and that the glycerol hydrogenolysis efficiency is influenced by the porosity and acidity of the support. A selectivity to 1,2-PDO of 81.3% at a glycerol conversion of 60.1% under 3 MPa H2pressure and 220 ℃ for 10 h was achieved over the modified Ru/HY catalyst with a 1.0 mol/L HCl treatment. It has also been shown that a longer reaction time, a higher temperature and a higher H2pressure have the positive effects on the glycerol hydrogenolysis efficiency of the enhanced Ru/HY.  相似文献   

9.
The nano materials often exhibit very interesting electrical, optical, magnetic, and chemical properties, which can not be achieved by their bulk counterparts. The development of uniform nanometer sized particles has been intensively pursued because of their technological and fundamental scientific importance. It is significant that nanostructured materials can be controllably assembled into the required geometry onto substrates, becoming the basis of the next generation of components and devices. The development of new methods and strategies for organizing the nanoparticle basic building blocks into the desired structures is required. Superlattices made from these building blocks give us the opportunity to study not only the properties of the individual building blocks, but also collective effects. The superparamagnetic iron oxide nanocrystals(NCs) have been used in the fields of bio-medicine, ferrofluids, refrigeration system, catalysis,  相似文献   

10.
An aromatic azo-polymer, poly(thiourea-azo-sulfone)(PTAS), has been prepared using 4-(4-aminophenylsulfonyl)benzenamine and diazonium salt solution of 2,6-diaminopyridine. PTAS was easily processable using polar solvents and had high molar mass 63 × 103g mol 1according to GPC. Mechanically and thermally stable and electrically conducting polymer/CNTs nano-composites were obtained via melt processing technique. Fine distribution of CNTs in a polymer matrix performed an essential role in the preparation of polymer/CNTs nano-composites based on interfacial interaction between CNTs and polymer matrix. Scanning electron micrographs showed good dispersion of filler and adhesion of matrix on the surface of nanotubes. Accordingly, increasing the amount of CNTs from 0.1 wt% to 5 wt% increased the electrical conductivity from 2.99 S cm 1to 3.56 S cm 1. Mechanical strength of functional nanotubes-based hybrids was enhanced from 43.22 MPa to 65.02 MPa compared with that of hybrids with non-functional filler in matrix 37.21 MPa. A rapport between nanotube loading and thermal stability of the materials was also observed. 10% gravimetric loss temperature was increased from 528 °C to 578 °C, while glass transition was improved from 241 °C to 271 °C. Adding up of small quantity of functional CNTs strongly affected the tensile, electrical and thermal properties of materials. Improvement of the physical properties of CNT-reinforced polymer nano-composites was ascribed to the melt processing technique.  相似文献   

11.
A series of novel Ni/CeO2-Al2O3composite catalysts were synthesized by one-step citric acid complex method. The as-synthesized catalysts were characterized by N2physical adsorption/desorption, X-ray diffraction(XRD), Fourier transform infrared(FT-IR) spectroscopy, hydrogen temperature-programmed reduction(H2-TPR), X-ray photoelectron spectroscopy(XPS) and thermogravimetry analysis(TGA). The effects of nickel content, calcination and reaction temperatures, gas hourly space velocity(GHSV) and inert gas dilution of N2on their performance of catalytic partial oxidation of methane(CPOM) were investigated. Catalytic activity test results show that the highest methane conversion(85%), the best selectivities to carbon monoxide(87%) and to hydrogen(95%), the excellent stability and perfect H2/CO ratio(2.0) can be obtained over Ni/CeO2-Al2O3with 8 wt% Ni content calcined at 700 ℃ under the reaction condition of 750 ℃, CH4/O2ratio of 2 : 1 and gas hourly space velocity of 12000 mL h-1 g-1. Characterization results show that the good catalytic performance of this composite catalyst can be contributed to its large specific surface area(~108 m2 g-1), small crystallite size, easy reducibility and low coking rate.  相似文献   

12.
Two new coordination polymers,[Zn(bdc)(1,3-bimb)]n(1) and {[Mn2(ox)2(1,3,5tib)4/3]·4H2O}n(2)(H2ox = oxalic acid,H2bdc = terephthalic acid,1,3-bimb = 1,3-bis(imidazol-1ylmethyl)benzene,1,3,5-tib = 1,3,5-tri(imidazol-1-yl)benzene),were synthesized and characterized by elemental analysis,IR,powder X-ray diffraction(PXRD),and thermogravimetric(TG) analyses.X-ray diffracation analysis reveals that two kinds of zigzag chains [Zn(bdc)]n and [Zn(1,3-bimb)]n in compound 1 are interweaved to form a 3D 4-fold interpenetrated 66-dia framework.In compound 2,Mn(1) and Mn(2) are linked via 1,3,5-tib ligands to form two different nets of [Mn6(1,3,5-tib)6 ]n along the ab plane with inner-or outer-shape N–Mn–N angles,which are connected by 1D infinite [Mn2(ox)2 ]n chains via Mn–O bonds to result in a(3,3,3,4,4)-connected(4·8·10)3(4·82)3(4·83·102)6(82·104·3)3(83)4 topology.Moreover,the photoluminescence of 1 has been investigated.The crystal of 1 crystallizes in orthorhombic,space group Pna2 with a = 13.2267(6),b = 9.1717(4),c = 17.4492(8),V = 2116.79(16)3,Z = 4,C22 H18N4O4 Zn,Mr = 467.77,Dc = 1.468 g/cm3,F(000) = 960 and μ(MoKα) = 1.197 mm-1.The final R = 0.0280 and wR = 0.0618 for 3695 observed reflections with I 2(I) and R = 0.0389 and wR = 0.0653 for all data.The crystal of 2 crystallizes in rhombohedral,space group R-3 with a = 22.080(8),c = 31.19(2),V = 13167(11) 3,Z = 18,C24 H25 Mn2 N8 O13,Mr = 743.40,Dc = 1.688 g/cm3,F(000) = 6822 and μ(MoKα) = 0.945 mm-1.The final R = 0.0429 and wR = 0.1035 for 5160 observed reflections with I 2(I) and R = 0.0824 and wR = 0.1244 for all data.  相似文献   

13.
The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer(IIR-SOFC) fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-SOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density(0.67 W cm-2)and electrical efficiency(68%) with an acceptable temperature gradient and a moderate pressure drop across the reformer(3.53×10-5kPa).IIR-SOFC with an annular-coated wall reformer was then studied over a range of operating conditions: inlet fuel temperature, operating pressure, steam to carbon(S : C) ratio, gas flow pattern(co-flow and counter-flow pattern), and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature(1223 K–1173 K)and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode(1-10 bar) improved the temperature gradient and cell performance. Increasing the S : C ratio from 2 : 1 to 4 : 1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-SOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.  相似文献   

14.
Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1H-NMR) spectroscopy. The differential scanning calorimetry(DSC) and the thermal gravimetric analysis(TGA) were used to characterize the thermal property of polymers. The results indicate that though the glass transition temperature(Tg) of polymers increases with increasing the ratio of NLO groups, the polymers with different ratios of NLO groups still all show low glass transition temperatures around 60 °C, and good thermal stability, which are favorable to the practical application of these polymers. The gel permeation chromatographic(GPC) result indicates that these polymers all have high-molecular-weight which is favorable to the long term stability of the material. Further, these polymers have good solubility in chloroform solvent, and the solutions can easily be fabricated into optically transparent films. Gain coefficients of 75 cm-1, 185 cm-1 and 66 cm-1 can be observed at zero external electric field without any addition agent or pre-poling for polymers P-2, P-3 and P-4 respectively. The different contents of NLO groups result in the different properties of polymers P-2, P-3 and P-4.  相似文献   

15.
姜华  孟祥军 《结构化学》2013,(9):1316-1324
B3LYP/6-31++G** method was applied to investigate the mechanism of alanine isomerization.12 minima and 22 transition states were obtained after optimization and several paths of isomerization were found.It is found that intramolecular single-bond rotation and proton transfer might lead to isomerization.The energy barrier of C–N bond rotation was lower than 2.52 kcal·mol 1,while the energy barrier ranges of the rotation of C–C and C–O were separately 0.43~ 7.01 and 4.69~12.19 kcal·mol 1,and the minimum energy barrier of proton transfer was 30.76 kcal·mol 1.The most probable isomerization path and mechanism for the two most stable conformations was discussed to find that the highest energy barrier to be crossed in this path was 11.87 kcal·mol 1.In order to understand the microscopic nature why only 4 conformations were detected in the experiment,thermodynamic properties of all conformations at the experimental temperature of 391 K was calculated.It is found that conformations XII,XI,X and IX can only unidirectionally convert into conformations rapidly with low energy and vanish immediately.The other conformations were distributed according to Maxwell-Boltzman's law,and the distribution probabilities of conformations I,II,III,IV,V,VI,VII and VIII were respectively 27.2%,26.5%,25.8%,6.4%,5.2%,4.8%,2.5% and 1.6%.Conformations I,II and III with bigger probability and stronger absorption peak were easy to detect in the experiment.Conformation IV had a relatively smaller probability(6.4%) and weak absorption peak which,however,could also be identified.The other conformations had too small probability to identify in the spectrum.  相似文献   

16.
黄伟  佘能芳 《结构化学》2013,(9):1357-1361
The crystal structure of the new title compound 2,2-dimethyl-4-oxochroman-3-ylmorpholine-4-carbodithioate(C16H19NO3S2,Mr = 337.44) has been prepared and determined by single-crystal X-ray diffraction.The crystal is of triclinic,space group P1 with a = 9.5518(7),b = 9.7172(7),c = 11.0220(8),α = 67.08(1),β = 74.66(1),= 61.31(1)°,V = 822.72(10)3,Z = 2,Dc = 1.362 g/cm3,F(000) = 356,μ = 0.092 mm-1,MoKa radiation(λ = 0.71073),R = 0.0515 and wR = 0.1389 for 2623 observed reflections with I > 2(I).X-ray diffraction analysis reveals that the chroman ring adopts a half-chair conformation while the morpholine ring shows a chair conformation.Intramolecular and intermolecular C-H···S and C-H···O hydrogen bonds together with π-π interations are found in the structure.The result of MTT assay shows the title compound displays good antiproliferative activity against two human cancer cell lines.  相似文献   

17.
王宗宝  顾群 《高分子科学》2013,31(12):1717-1724
Lamellar crystals of diblock, triblock and four-arm poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-b-PCL) crystalline-crystalline copolymers were successfully obtained from their solution. Morphology and structure of lamellar crystals of crystalline-crystalline copotymers were investigated using tapping-mode atomic force microscopy (AFM) and selected area electron diffraction (SAED). All of these samples showed the truncated-lozenge multilayer basal shapes with central screw dislocation or central stack, which were all obtained simultaneously from the oil bath. The diffraction pattern of PEG block lamellar crystal is attributed to the (120) diffracting planes and the pattern of PCL block lamellar crystal is attributed to the (1 I0) diffracting planes and (200) diffracting planes according to the SAED results. Four (110) crystal growth planes and two (200) crystal growth planes are discovered for the PCL blocks, but the (120) crystal growth planes of PEG blocks are hided in the figure of AFM. The crystalline structure of the four-arm copolymers (FA) is more disorder and confused than that of the diblock (DI) copolymer and the striated fold surface structures of lamellar crystals of four-arm copolymers (FA) are smoother than these of linear analogues, owing to the confused crystallization of blocks caused by the mutual restriction of blocks and the hindrance of the dendritic cores. In addition, the aspect ratio of FA is greater than that of the others. It is hypothesized that there are two reasons for the change of aspect ratios. First, the (200) diffracting planes of PCL crystals grew slowly compared to their (110) diffracting planes because of difference in the energy barrier. Secondly, edge dislocations on the (200) diffracting planes are also responsible for the variation of the aspect ratio. Consequently, the crystalline defects are augmented by the competing blocks crystallized simultaneously and the hindrance of the dendritic cores.  相似文献   

18.
In this paper,21 substituents with various electron donating and electron withdrawing characters were placed in the available positions of Licoisoflavone in order to study their effect on the three O–H bond dissociation enthalpies and ionisation potential via DFT/B3LYP method.Results show that the B-ring is more important than the A-ring from the BDE and IP point of view because the radical structure formed after hydrogen atom abstraction from the 4-OH group can be stabilized by the resonance between the three rings.The results show that intramolecular hydrogen bonding effects are able to considerably stabilize the parents and radicals.The NBO analysis results also confirmed the intramolecular hydrogen bond stabilization.The formation of strong intramolecular hydrogen bonds and suitable spin density distributions in several radicals result in low BDE and IP values.The calculated BDE and IP values have been correlated with Hammett constants.The found dependencies are suitably linear,which can be important for the synthesis of novel antioxidants based on Licoisoflavone.  相似文献   

19.
侯向阳  王潇  付峰  王记江 《结构化学》2013,(9):1339-1347
Two new PbII metal-organic coordination polymers,namely,[Pb(tda)]n(1) and [Pb(tda)(phen)]n(2)(H2 tda = thiodiglycolic acid,phen = 1,10-phenanthroline),were synthesized under hydrothermal conditions and characterized by elemental analysis,IR,UV spectra,TG technique and X-ray crystallography.Complex 1 crystallizes in the orthorhombic system,space group Iba2 with a = 9.0417(14),b = 19.360(4),c = 7.5741(12),C4H4O4PbS,Mr = 355.32,V = 1325.8(4)3,Dc = 3.560 g·cm-3,F(000) = 1264,μ(MoKa) = 25.711 mm-1,S = 1.086 and Z = 8.The final refinement gave R = 0.0387 and wR = 0.0986 for 3077 observed reflections with I > 2σ(I).Complex 1 is a 2D infinite grid-like(4,4) topological structure constructed by PbII atoms and tda anions,in which tda ligands exhibit bis(syn,syn-bridging bidentate,chelating-bridging tetradentate) mode.Complex 2 crystallizes in the triclinic system,space group P1 with a = 8.3570(17),b = 8.7591(18),c = 10.895(2),α = 76.00(3),β = 80.50(3),γ = 77.61(3)°,C16H12N O4PbS,Mr = 535.53,V = 750.4(3)3,Dc = 2.370 g·cm-3,F(000) = 504,μ(MoKa) = 11.405 mm-1,S = 1.018 and Z = 2.The final refinement gave R = 0.0332 and wR = 0.0629 for 3360 observed reflections with I > 2σ(I).Complex 2 is a 1D chain structure,in which phen ligands are attached on both sides of the 1D chain and tda ligand exhibits a bis(syn,syn-bridging bidentate,chelating tridentate) mode.Finally,complex 2 is extended into a 2D supramolecular structure by strong π···π stacking interactions.  相似文献   

20.
Dye sensitized solar cell(DSSC) is a promising thin film solar cell that has been widely investigated after its birth because of its advantages,such as flexibility,low-cost,easyfabrication and so on[1-3].For DSSCs,sensitizers play a core role due to their responsibility for the generation of the photo carriers resulted from light absorption and the transfer of the photo-generated electrons into semiconductor photoanodes[4].Keywords:Light-harvesting complex Ⅱ; Anthraquinone 2-carboxylic acid; ZnO; TiO2 nanostructure; Solar cell  相似文献   

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