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1.
有机体系中电合成纳米PbTiO3粉体及表征   总被引:1,自引:0,他引:1  
The precursor PbTi(OCH2CH3)6-y(acac)y for the mixed oxide PbTiO3was synthesized by electrochemical dissolution of Lead and Titanium with a 1∶2 electricity quality in ethanol and acetyl-acetone solution. Nano-sized PbTiO3powder was prepared by drying and calcining the xerogel from a direct sol-gel hydrolyzation of the precursor solution under pH of 8.5. The FTIR, TG-DTA, XRD and TEM were employed to characterize the structure of the precursor and nano-sized PbTiO3. The results showed that the optimized conditions for the preparation of nano-sized PbTiO3 were the electrolysis of the Lead plate and Titanium plate at 50 ℃ and 40 ℃ respectively under 0.03mol·dm-3Bu4NBr solution. The nano-sized PbTiO3prepared by electrolysis exhibited a dispersive structure with an average diameter of 10 to 15 nm.  相似文献   

2.
Mg and Al alkoxide complex was synthesized in a cell without battery separator by electrochemical dissolution of aluminum for 6 h and magnesium for 1.8 h at 45 ℃ in ethanol solution of 0.04 mol·dm-3 (Bu4N)Br with a current density of 100 mA·cm-2. IR and Raman spectroscopy were used to characterize the structure of the precursor of MgAl2O4. The results show that the current efficiency attains 98.4% and the precursor is MgAl2(OCH2CH3)5(acac)3. The acac- group-containing precursor could prevent it from agglomeration. The xerogel was obtained by drying in vacuum for 24 h and hydrolysis under pH≈8.5 of the precursor, which was heated at 350 ℃ for 2 h to obtain the nano-MgAl2O4 powder. XRD and TEM were used to investigate the structure of nano-MgAl2O4. The result suggests that the xerogel with an average particle size of 10 nm and the Nano-sized Spinel MgAl2O4 Particle of 12 nm thus obtained are with high purity.  相似文献   

3.
Lead complex was directly synthesized by electrochemical dissolution of lead in a cell without separating the cathode and anode. The product was characterized by FTIR, Raman spectra and 1H NMR. The xerogel was prepared by a direct sol-gel of the electrolyte solution and then dryness of it. The xerogel was heated at 450 ℃ for 2 h to obtain the nano-PbO powder. FTIR, XRD, and TEM were used to investigate the structure of nano-PbO. The results show that the lead complex is Pb(OEt)2(acac)2, which contains acac- group and could prevent the precursor from hydrolysis and sintering during the calcinations process. The nano-PbO of 20~30 nm was thus obtained in a high purity by drying at 450 ℃.  相似文献   

4.
A series of (Ag0.9Li0.1)(Nb1-yTay)O3 ceramic powders were prepared by an aque-chemical method. The optimized calcination temperature, time and crystal lattice were studied by TG-DTA, IR, XRD and TEM. The results show that the optimized conditions were calcination of the precursor at 800 ℃ for 2 h. The ceramic powder thus prepared was rhombohedral with the average grain size of 48 nm.  相似文献   

5.
A mesoporous (d=2.3mm) silica-pillared layered tetratitanate with a super gallery (d001=1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine, then reacting with 20wt% NH2(CH2)3Si(OC2H5)3 aqueous solution, and finally calcinating the resultant solid product in air at 550℃. All the reaction was carried out hydrothermally in an autoclave at 130℃. The obtained material has a relatively high BET surface area of 204m2·g-1 and a thermal stability beyond 600℃. The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.  相似文献   

6.
三唑酮氯化锌配合物的合成和晶体结构研究   总被引:3,自引:0,他引:3  
The new compound was synthesized by the reaction of ZnCl2 and triadimefon(ratio 1∶2) in ethanol solution refluxing for 6 hours. The crystal used for X-ray analysis was obtained by slow evaporation of the solution at room temperature. It crystallizes in the monoclinic system, space group P2/n. The lattice parameters are: a=1.58916(6)nm, b=0.60634(2)nm, c=1.83566(8)nm, β=93.979(2)°, V=1.7645(1)nm3, Z=2, Dc=1.362g·cm-3, F(000)=744.00, μ(Mo Kα)=1.038mm-1, R1=0.042, wR2=0.106. In the complex, the Zn(Ⅱ) cation is tetrahedrally coordinated to two triadimefon ligands and two chloride in cis disposition. The title complex was also characterized by elemental analysis, molar conductance, IR and TG-DTA. CCDC: 207413.  相似文献   

7.
甘氨酸燃烧合成YAG∶Tb荧光粉的微观结构和发光特性   总被引:4,自引:0,他引:4  
Luminescent terbium doped yttrium aluminum garnet (YAG∶Tb) powders were prepared using yttrium and aluminum oxide precursor particles produced by combustion process with glycine. Heat treatment of the resulting precursor powders at 950℃ or 1450℃ for 2h, yielded pure YAG particles. The morphology of YAG∶Yb phosphor after sintering at 1450℃ appeared to be spherical or elliptical and the grain size of the phosphor was in the range of 0.6 to 1.4μm. From the photoluminescence spectra, transitions 5D4- 7FJ corresponding to Tb3+ in YAG matrices were identified. The prominent transition 5D4- 7F6 emission for YAG∶0.05Tb phosphor after sintering at 1450℃ was very significant to improve the chromaticity of YAG∶Tb phosphor.  相似文献   

8.
A high-performance liquid chromatographic method for the determination of levamisole (LVM) residues in sheep muscle tissue is described. LVM was extracted with ethyl acetate under alkaline conditions and cleanup was performed by liquid-liquid partition between organic-basic and organic-acid medium. Finally, levamisole was back extracted with chloroform carefully transferred into a clean glass vial and evaporated to dryness at 50 °C under a gentle stream of nitrogen. The remaining dry residue was dissolved in the mobile phase used, filtered and an aliquot was injected automatically into the chromatograph for analysis. Chromatography was performed on a Zorbax?SB-C18 column at 50 °C and detection by a PDA detector monitored at λmax 220 nm. The mobile phase was a mixture of 0.1 % trifluoroacetic acid (v/v) pH 2.0 and acetonitrile-methanol 3 : 2 (v/v) in a combination of 30 : 70 (v/v) and a flow rate of 1.0 mL min−1, delivered isocratically. This analytical method was validated by assessing recovery efficiency using spiked muscle tissue samples with standard solutions in methanol at four fortification levels of 1/2 MRL, 1 MRL, 2 MRL and 4 MRL and five times for each concentration (n = 5). Mean recovery (R%) achieved for muscle tissue was 75.65 ± 2.74% with an acceptable Relative Standard Deviation RSD% = 10.4. The same method was used also for the analysis of kidney, liver and fat (perirenal) and the recoveries found were 70.25 ± 1.07% (RSD% = 1.52), 72.37 ± 3.6% (RSD% = 4.97) and 69.44 ± 2.22% (RSD% = 3.19), respectively. The limit of detection (LOD) for muscle tissue was found to be 2.0 μg kg−1 and the limit of quantification (LOQ) 5.0 μg kg−1. Revised: 4 and 24 January 2006  相似文献   

9.
Ni–La/SiO2 catalysts were prepared by using a new metal organic precursor M(OC3H7)n, dissolved in organic solvent, hydrolysed and finally condensed to form inorganic polymers containing M–O–M or M–(μOH)–M linkages. An optimal distribution of both the active phase ‘Ni’ and the promoter ‘La2O3’ was ensured by addition of their corresponding salts, previously dissolved in propionic acid, to a silica solution prior to gelation. After drying under vacuum the precursor was submitted to thermal treatment in air at 600°C with a heating rate of 1°C min–1. The precursors and the corresponding catalysts were characterised by various techniques (TG-DTA, XRD, FTIR, TEM, BET and porosimetry) and tested for methane dry reforming. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

10.
新配合物[Cd(H2O)2(phen)2](PA)2的制备及晶体结构   总被引:2,自引:0,他引:2       下载免费PDF全文
The new compound was prepared by the reaction of Cd(ClO4)2·6H2O,1,10-phenanthroline (phen)and picric acid (HPA)(ratio 1∶3∶2) in methanol-aqueous solution refluxing for 4 hours. The crystals used for X-ray analysis was obtained by slow evaporation of the solution at room temperature. The crystal compound is in triclinic with space group with a=1.1363(4)nm,b=1.2593(2)nm,c=1.3972(4)nm,α=93.97(2)?,β=100.84(3)?,γ=106.29(2)?,Z=2,V=1.8690(9)nm3,Dc=1.715g·cm-3, μ(MoKα)=0.677mm-1,F(000)=972,R=0.0907,wR=0.2240. In the complex, the Cd(Ⅱ) cation is octahedrally coordinated to two 1,10-phenanthroline ligands and two water molecules in cis disposition. As outer sphere, picrate anions are combined with inner by hydrogen bond and static electricity interaction.  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

14.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

15.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

16.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

17.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
20.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

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