取代苯亚胺基噻唑啉的合成和抑菌活性

2-取代苯亚胺基噻唑啉化合物 ( )中的双键可以在环上或在环外 ,在一定条件下 ,两种异构体可以相互转换 .Ar为单取代或多取代的芳基 .先导化合物　唑烷酮是一种海藻类的毒素[1 ] ,能衍生出一些具有生物活性的化合物 .我们曾对此类化合物的植物激素活性和除草活性进行过研究 [2 ] ,也有文献对其动物麻醉效能进行了报道 [3] .本文采用改进的合成方法制备了 2 -取代苯亚胺基噻唑啉化合物 ,并进行了生物测定 ,发现其具有很好的抑菌活性 ,有的化合物未见文献报道 .标题化合物按下列途径合成 :NH2 CH2 CH2 OH H2 SO4 H2 NCH2 CH2 OSO3H C…     

基于磷钼酸和2-(2-羟基苯)苯并咪唑复合物的晶体结构和质子导电性(英文)

以磷钼酸和2-(2-羟基苯)苯并咪唑(L)为原料制备了具有质子导电性的有机-无机化合物[H3L2(PMo12O40)·7H2O·4CH3OH]n(1).单晶X射线衍射分析结果表明化合物1具有基于磷钼酸、2-(2-羟基苯)苯并咪唑及溶剂甲醇分子的二维氢键网络结构;质子导电性能测试结果表明该化合物在100℃、相对湿度为98%时的电导率达到10-4 S·cm-1.     

微波辐射下干反应脱肟成酮的一种新方法

肟已被广泛用于羰基化合物的表征、纯化以及酰胺的合成[1 ] 。人们可以从羰基和非羰基化合物来制备肟 (Ｂａｒｔｏｎ反应[2 ,3] )。因此 ,肟的脱肟成酮也是合成羰基化合物的一种方法。近年来 ,文献中不断有各种脱肟试剂和催化剂 ,如 :三氧化铬 硅胶[4] 、镍 (Ⅱ )复合物[5] 等的研究报道。但这些方法都是在液相中进行的 ,通常需要计量或过量的有机试剂 ,而且反应时间长、产率低[6] 。为了寻找高效的脱肟方法 ,微波辐射下的干反应脱肟研究已愈来愈引起人们的兴趣[1 ,7] ,它具有反应速度快、副反应少、产率高等优点。前文[8] 我们报道了用甲酸…     

硫化银纳米晶的γ辐射制备

γ射线辐射法是一种在常温常压下制备纳米材料的方法 ,它是利用水在γ射线的作用下产生的大量还原性粒子 (如水合电子等 )把许多金属离子还原 ,或者把一些较高价态的非金属元素 (如硫 )还原成最低价态 ,以制备纳米金属粒子 [1～ 3]、纳米合金粉末 [1～ 4 ]、纳米金属氧化物粉末 [5]、纳米复合材料 [6]和半导体硫化物纳米材料 [7]等 .但对硫化物的研究仅局限于 B- A族化合物 .现在 ,各种 B- A族化合物纳米材料的制备研究也逐渐受到人们的关注 ,因为这些化合物同时具有部分电子导电性能和部分离子导电性能 ,可用作超离子导体和半导体 [8…     

含混合价态钒的晶体[N(CH3)4]4[H5PMo5V9O42]·3.5H2O的合成与结构

含有钒和钼的化合物在催化、抗病毒药物、功能材料等领域具有广阔的应用前景 [1～ 4 ] .近年来 ,钒取代的杂多化合物或金属 -氧簇的合成与表征已引起人们的广泛关注 ,许多新的化合物已被合成 ,如含五价钒的化合物 K7[Mo8V5O4 0 ]· 8H2 O和 Na3[VMo12 O4 0 ]· 1 9H2 O[5,6 ] ,含有混合价态钒的簇阴离子[( V V Mo10 ) VO4 0 ]6 - 和 [Mo8V V4 O4 0 ]8- 的化合物 [7,8] ,含双帽 Keggin 结构的簇阴离子[PMo6 VMo6 O4 0 ( V O) 2 ]5- 和 [PMo8V 4 V 2 O4 2 ]5- 的化合物 [9,10 ] 等 ,但所报道的含混合价态钒的 V- Mo化合物中含…     

用硅胶担载三氯化铁催化氧化偶联2-萘酚制备(±)2,2′-二羟基-1,1′-联萘

2,2′-二羟基 - 1 ,1′-联萘 ,由于存在受阻 C- C键轴 ,可通过拆分获得对映体纯手性双膦配体BINAP的前体 [1] ,或经不对称氧化转化成催化剂前体 [2 ] ,或用作手性试剂 ,近年来备受人们的重视 .其常用制备方法多以 Fe3 、 Mn3 及 Cu2 氧化 2 -萘酚 .尤以 Fe3 [3～ 5] 为氧化剂制备 (± ) 2 ,2′-二羟基 -1 ,1′-联萘最为经济 .传统上以甲醇 /水 ( 1 /1 ,体积比 )为介质 ,用 Fe Cl3 氧化 2 -萘酚制 (± ) 2 ,2′-二羟基 - 1 ,1′-联萘 ,产率不太高 [5] .近年来 ,Toda等 [5]利用固态反应及超声波制备此化合物 ,收率明显提高 ,但…     

α-芳基-α-羟基酮(酯)与全氟烷基磺酰氟/甲基三乙氧基硅烷/碱体系不期望的氧化反应

研究了全氟烷基磺酰氟/甲基三乙氧基硅烷/碱体系与α-芳基-α-羟基酮(酯)化合物不期望的氧化反应,以中等到优良的收率生成了相应的1,2-二酮(α-酮酸酯)产物.所用全氟烷基磺酰氟为全氟正丁基磺酰氟或全氟正辛基磺酰氟;碱为1,8-二氮杂二环[5.4.0]十一碳-7-烯(DBU).提出了一种可能的反应机理.为制备芳基取代的1,2-二酮(或α-酮酸酯)化合物提供了一种新方法.     

用高浓度杂多酸溶液催化苯甲醚与乙酸酐的酰化反应

芳香化合物经Friedel-Crafts酰化反应制备药物和香料中间体芳香酮是近年来人们感兴趣的课题^[1-4]。用于该反应的传统催化剂是Lewis酸金属氯化物。由于反应过程中催化剂可与酰化试剂羧基产物形成配合物,因而催化剂用量大,且所形成的配合物水解后产生大量废液。为了减少环境污染,人们已成功地用分子筛催化剂代替传统催化剂催化芳香化合物的酰化反应^[5-7]。其中包括用分子筛催化各种芳香化合物与乙酸酐的酰化反应^[8]。我们已经研究了用杂多酸－乙酸浓溶液催化异丁烷与丁烯的烷基化反应^[9,10],以及烯烃与羧酸的直接酯化反应^[11]。本文将报道杂多酸－乙酸浓溶液对苯甲醚与乙酸酐酰化反应的催化活性。     

去甲斑蝥酰亚胺及其类似物的N-Mannich碱

本文报导7-氧杂双环[2,2,1]庚-5-烯-2,3-二酰亚胺及其还原产物--去甲斑螯酰亚胺的制备及其某些化学反应。由这两种酰亚胺出发,合成了35种新的N-Mannich碱。鉴于文献报导类似结构化合物的生理活性,我们合成的N-Mannich碱有可能也具有某种生理活性。     

石墨与聚苯乙烯的纳米复合过程研究

石墨具有电导率高、化学稳定性好等优点 ,被广泛应用于聚合物 石墨复合导电材料[1～ 3] .石墨作为聚合物导电填料一般以粉末形态居多 .用粉末状石墨填料往往需要较高的填充量才能得到理想的导电性能 .石墨也可以制备成膨胀石墨 ,将它与聚合物复合 ,可以大幅度降低石墨的填充量 .如一般粉末状石墨填料与聚合物复合制备的导电材料其逾渗阀值为 1 5 %～ 2 0 % ,电导率达到 1 0 -4 ～1 0 -7Ｓ ｃｍ[4 ] ;而若采用膨胀石墨方法 ,逾渗阀值则低于 3% ,电导率可达到 1 0 -2 Ｓ ｃｍ以上[5～ 7] .Ｐａｎ等[7] 报道用膨胀石墨与聚合物复合得到纳米复合…     

Size-controlled synthesis of monodispersed mesoporous α-alumina spheres by a template-free forced hydrolysis method

We demonstrated the formation of monodispersed spherical aluminum hydrous oxide precursors with tunable sizes by controlling the variables of a forced hydrolysis method. The particle sizes of aluminum hydrous oxide precursors were strongly dependent on the molar ratio of the Al(3+) reactants (sulfates and nitrates). In addition, the systematic phase and morphological evolutions from aluminum hydrous oxide to γ-alumina (Al(2)O(3)) and finally to α-Al(2)O(3) through thermal dehydrogenation were characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). After annealing the amorphous aluminum hydrous oxide in air at 900 °C and 1100 °C for 1 h, we observed complete conversion to phase-pure γ- and α-Al(2)O(3), respectively, while maintaining monodispersity (125 nm, 195 nm, 320 nm, and 430 nm diameters were observed). Furthermore, both γ- and α-Al(2)O(3) were found to be mesoporous in structure, providing enhanced specific surface areas of 102 and 76 m(2) g(-1), respectively, based on the Brunauer-Emmett-Teller (BET) measurement.     

Preparation and coating of finely dispersed drugs 4. Loratadine and danazol

The preparation of colloidal particles of different morphologies, including spheres, of two drugs, loratadine and danazol, is described. In principle these particles were obtained by precipitation when nonsolvents (water or aqueous surfactant solutions) were added to ethanol solutions of the drug. In addition, procedures were developed that made it possible to use the drug particles thus obtained as cores to be then coated with either silica or aluminum (hydrous) oxide layers. The presence of these inorganic shells was confirmed by electron microscopy, energy dispersive spectroscopy, and electrophoresis.     

Direct formation of thermally stabilized amorphous mesoporous Fe2O3/SiO2 nanocomposites by hydrolysis of aqueous iron III nitrate in sols of spherical silica particles

Nanocomposite materials containing 10% and 20% iron oxide/silica, Fe2O3/SiO2 (w/w), were prepared by direct hydrolysis of aqueous iron III nitrate solution in sols of freshly prepared spherical silica particles (St?ber particles) present in their mother liquors. This was followed by aging, drying, calcination up to 600 degrees C through two different ramp rates, and then isothermal calcinations at 600 degrees C for 3 h. The calcined and the uncalcined (dried at 120 degrees C) composites were characterized by thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), N2 adsorption/desorption techniques, and scanning electron microscopy as required. XRD patterns of the calcined composites showed no line broadening at any d-spacing positions of iron oxide phases, thereby reflecting the amorphous nature of Fe2O3 in the composite. The calcined composites showed nitrogen adsorption isotherms characterizing type IV isotherms with high surface area. Moreover, surface area increased with the increasing of the iron oxide ratio and lowering of the calcination ramp rate. Results indicated that iron oxide particles were dispersed on the exterior of silica particles as isolated and/or aggregated nanoparticles. The formation of the title composite was discussed in terms of the hydrolysis and condensation mechanisms of the inorganic FeIII precursor in the silica sols. Thereby, fast nucleation and limited growth of hydrous iron oxide led to the formation of nanoparticles that spread interactively on the hydroxylated surface of spherical silica particles. Therefore, a nanostructured composite of amorphous nanoparticles of iron oxide (as a shell) spreading on the surface of silica particles (as a core) was formed. This morphology limited the aggregation of Fe2O3 nanoparticles, prevented silica particle coalescence at high temperatures, and enhanced thermal stability.     

Effect of the nature of anions of aluminum salts used to synthesize a precursor of the Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-ZrO<Subscript>2</Subscript> ceramics on the stabilization of the tetragonal modification of zirconium dioxide

Samples of a precursor for an aluminum oxide ceramics reinforced with zirconium oxide were synthesized by hydrolysis of various aluminum salts in the presence of a ZrO₂ sol under conditions of urea decomposition at 90°C and pH < 4 maintained, with hydrolysis products deposited onto the surface of ZrO₂ sol particles. It was found that the nature of a salt anion affects the interaction of hydrolysis products of the aluminum cation with the surface of ZrO₂ sol particles. The structure of products formed in thermal treatment of samples of a precursor for Al₂O₃-ZrO₂ (T = 1250°C) was characterized by X-ray phase analysis and scanning electron microscopy. The phase transition temperatures of the oxides Al₂O₃ and ZrO₂ contained in the precursor were estimated using the results of thermal analysis of the samples in the temperature range 20–1300°C.     

Y(OH)CO3在AgI上的覆盖及中空粒子的制备

用银配合物制备均匀球形AgI纳米粒子,粒径20～100 nm范围内可自由调控.用AgI作为内置核,在尿素存在下,将Y(NO3)3进行升温水解,在预置粒子上包覆Y(OH)CO3形成复合粒子,并符合表面膜机理.结合X射线、电镜照片,考察了Y(NO3)3、尿素、银配合物、内置核的浓度,反应时间,水解温度,表面电荷对反应体系的影响.并加入配合剂Na2S2O3,运用生成稳定配合物的方法溶解内置核,最终得到Y(OH)CO3中空粒子.     

Gravitational field-flow fractionation in combination with flow injection analysis or electrothermal AAS for size based iron speciation of particles

A simple gravitational field-flow fractionation (GrFFF) system was used for size separation of micron sized silica particles coated with hydrous iron oxide (geothite). The amount of iron on the particles was monitored either on-line by reverse-flow injection analysis (r-FIA) with chemiluminescence detection using luminol or off-line by electrothermal atomic absorption spectrophotometry (ETAAS). The combination of GrFFF with reverse FIA or with ETAAS has been demonstrated to be a cost-effective tool for size based iron speciation of particles.     

Aluminium nitrate as a precursor of mesoporous aluminium oxides

The thermal transformations of the products of hydrous aluminium nitrate hydrolysis in ammonia medium were studied by thermal analysis, mass spectrometry, infrared spectrophotometry, X-ray phase analysis, and sorption methods. Experiments have shown that the hydrolysis of hydrous aluminium nitrate in ammonia medium at pH=6-7 leads to the formation of boehmite. The degree of crystallinity of this product increases, if the hydrolysis is carried out for 264 h at 100°C, with respect the samples separated from the mother liquor just after completing the dosage of the reagents. It has also been found that aluminium oxide, obtained by thermal decomposition of the products of hydrolysis carried out for 264 h at an increased temperature, is characterized by a well developed specific surface, stable at high temperatures, amounting to about 100 m2 g^-1, after calcination for 2 h at 1200°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and optimization of magnetic technologies based processes for removal of some toxic heavy metals

In the developing countries where the cost is often a decisive factor, extensive studies were undertaken to test the most effective factors on the preparation, optimization and validation of the magnetic particles (or, more accurately, magnetizable particles) for removal of heavy metals from wastewaters. The objective of the proposed work was focused to provide promising solid-phase materials, which, are relatively in expensive and combine high surface capacity with fast efficient treatment. Four various metal oxides including hydrous ferric oxide (HFO), hydrous stannic oxide (HSO) and mixed ferric/stannic oxide (HMO), were prepared by precipitation with ammonia from metal chloride solutions. Two mixed oxides were prepared with different Sn/Fe ratios of 50% and 20%. Optimal conditions for the activation of these particles and the subsequent mixing of various metals oxides are tested together with the utility of the method to get a new composite material with developed chemical characteristics over their individual metal oxides. Factors affecting the sorption behavior of the prepared samples in basic and acid media were elucidated. The magnetic treatment procedure using the mixed oxide (50%) enables the equilibration step to be carried out rapidly mainly due to ferric oxide during the magnetization process and efficiently due to high capacity of the stannic oxide. A key factor in achieving very high uptake percentage is the reduction of non-specific binding of various heavy metals to the solid phase support. This is usually achieved by increasing the ion exchange capability, in addition to their adsorption process.     

Preparation of uniform spherical aluminum hydrous oxide particles from acetylacetonato-aluminum solutions

Uniform spherical particles of amorphous aluminum hydrous oxide (0.45 m in diameter with a relative standard deviation of 0.09) were produced under a limited set of conditions in an aluminum sulfate/acetylacetone system at 100°C aged for 24 h. Grain-like crystalline -AlOOH particles (2.6 m in length with a relative standard deviation of 0.10) were also prepared in the absence of sulfate ions at 100°C for 42 h. Their morphology and size were sensitive to the total aluminum concentration, even though the initial pH was kept the same. The temperature dependence of the absorption spectra of acetylacetonato-aluminum complexes indicated their exothermic formation. These complexes release free aluminum ions at elevated temperatures, which subsequently hydrolyzed. The resulting polymerized hydroxo-aluminum species complexes with the sulfate ion act as precursors to particle formation.     

Characterization of an effective cleaning procedure for aluminum alloys: surface enhanced Raman spectroscopy and zeta potential analysis

We have developed a cleaning procedure for aluminum alloys for effective minimization of surface-adsorbed sub-micrometer particles and nonvolatile residue. The procedure consists of a phosphoric acid etch followed by an alkaline detergent wash. To better understand the mechanism whereby this procedure reduces surface contaminants, we characterized the aluminum surface as a function of cleaning step using surface enhanced Raman spectroscopy (SERS). SERS indicates that phosphoric acid etching re-establishes a surface oxide of different characteristics, including deposition of phosphate and increased hydration, while the subsequent alkaline detergent wash appears to remove the phosphate and modify the new surface oxide, possibly leading to a more compact surface oxide. We also studied the zeta potential of <5 microm pure aluminum and aluminum alloy 6061-T6 particles to determine how surface electrostatics may be affected during the cleaning process. The particles show a decrease in the magnitude of their zeta potential in the presence of detergent, and this effect is most pronounced for particles that have been etched with phosphoric acid.