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离子液体中微波促进的Knoevenagel缩合反应 总被引:8,自引:1,他引:8
以离子液体1-丁基3-甲基咪唑四氟硼酸盐为反应溶剂,氨基乙酸为催化剂,在微波辐射下,醛和活泼亚甲基类化合物发生的Knoevenagel缩合反应速度能被极大地提高,8种缩合产物被快速高收率地合成。 相似文献
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离子液体中微波促进的Biginelli缩合反应 总被引:10,自引:0,他引:10
在微波辐射下,以离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)为催化剂,三组分一锅法Bigi-nelli缩合反应快速地合成了10种高收率的5-乙氧羰基4-芳基二氢嘧啶酮衍生物的缩合产物,其结构经IR和^1H NMR确证。 相似文献
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微波助离子液体中纳米TiO2/PMMA复合材料的制备及光催化性能 总被引:1,自引:0,他引:1
微波加热法合成离子液体[Bmim]BF4,并以该离子液体为反应介质,在微波辐射条件下制备纳米TiO2/PMMA复合材料.用XRD,IR和TG对该复合材料进行测试和表征;并在高压汞灯下用甲基橙溶液对其进行光催化降解性能测试.结果表明,制备TiO2/PMMA复合材料的最佳条件是:离子液体1.7mL,钛酸丁酯与MMA的体积比为3.4∶1.0,微波辐射功率600W、反应温度70℃、反应时间35min.并且用[Bmim]BF4作为反应介质,能够显著提高TiO2/PMMA复合材料的光催化活性,所制备的TiO2/PMMA复合材料不需要经过高温煅烧,就表现出极高的光催化活性;TiO2负载PMMA后,复合材料的光催化活性得到了进一步的改善.该复合材料对甲基橙的降解率在1.5h就可达到98.4%,其活性明显优于未负载的纳米TiO2催化剂. 相似文献
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Brφnsted酸性离子液体催化合成阿司匹林 总被引:7,自引:0,他引:7
用Brφnsted酸性离子液体[Hmim]BF4、[bmim]HSO4和[bmim]H2PO4代替浓H2SO4为催化剂催化乙酸酐对水杨酸的乙酰化,合成阿司匹林。考察了反应温度、反应时间、催化剂用量、酐/醇摩尔比对水杨酸酰化反应产率的影响和离子液体的重复使用性能。选择了最佳反应条件,以[bmim]H2PO4作为催化剂,催化剂用量为0.28g(1.18×10-3mol),水杨酸2.762g(0.02mol),乙酸酐4.083g(0.04mol),n(酐)∶n(醇)=2∶1,反应时间30min,反应温度70℃,产率最高达63.43%,并且[bmim]H2PO4溶于水后通过过滤和旋蒸脱水,重复使用3次,产率无明显变化。 相似文献
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离子液体介质中微波辅助制备铁掺杂纳米TiO_2及光催化活性 总被引:1,自引:0,他引:1
在1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)离子液体中,用微波干燥的方法制备了铁掺杂的纳米TiO2-Fe光催化剂,并以甲基橙为模拟污染物,紫外灯为光源,考察了离子液体加入量、铁掺杂量、微波干燥功率、微波干燥时间、煅烧温度、煅烧时间等因素对TiO2-Fe光催化活性的影响.结果表明:在离子液体加入量为5.6 mL,掺杂物质硝酸铁与钛酸丁酯的物质的量百分比为0.005%,于家用微波炉中在210 W功率下干燥17.5 min,再在高温箱式电阻炉中于540℃煅烧处理1.5 h后所制得的TiO2-Fe光催化剂,分别用紫外光照90 min及太阳光照射3 h后,甲基橙都几乎达到完全降解,其活性明显优于未掺杂纯TiO2的光催化活性. 相似文献
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用Brcnsted酸性离子液体[Hmim]BF4、[bmim]HSO4和[bmim]H2PO4代替浓H2SO4为催化剂催化乙酸酐对水杨酸的乙酰化,合成阿司匹林。考察了反应温度、反应时间、催化剂用量、酐/醇摩尔比对水杨酸酰化反应产率的影响和离子液体的重复使用性能。选择了最佳反应条件,以[bmim]H2PO4作为催化剂,催化剂用量为0.28g(1.18×10^-3mol),水杨酸2.762g(0.02mol),乙酸酐4.083g(0.04mol),n(酐):n(醇)=2:1,反应时间30min,反应温度70℃,产率最高达63.43%,并且[bmim]H2PO4溶于水后通过过滤和旋蒸脱水,重复使用3次,产率无明显变化。 相似文献
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Matthias F. Groh Dr. Anna Isaeva Prof. Dr. Michael Ruck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):10886-10891
Two polymorphs of the new cluster compound [Ru2Bi14Br4](AlCl4)4 have been synthesized from Bi24Ru3Br20 in the Lewis acidic ionic liquid [BMIM]Cl/AlCl3 ([BMIM]+: 1‐n‐butyl‐3‐methylimidazolium) at 140 °C. A large fragment of the precursor’s structure, namely the [(Bi8)Ru(Bi4Br4)Ru(Bi5)]5+ cluster, dissolved as a whole and transformed into a closely related symmetrical [(Bi5)Ru(Bi4Br4)Ru(Bi5)]4+ cluster through structural conversion of a coordinating Bi82+ to a Bi5+ polycation, while the remainder was left intact. Both modifications have monoclinic unit cells that comprise two formula units (α form: P21/n, a=982.8(2), b=1793.2(4), c=1472.0(3) pm, β=109.05(3)°; β form: P21/n, a=1163.8(2), b=1442.7(3), c=1500.7(3), β=97.73(3)°). The [Ru2Bi14Br4]4+ cluster can be regarded as a binuclear inorganic complex of two ruthenium(I) cations that are coordinated by terminal Bi5+ square pyramids and a central Bi4Br4 ring. The presence of a covalent Ru? Ru bond was established by molecular quantum chemical calculations utilizing real‐space bonding indicator ELI‐D. Structural similarity of the new and parent cluster suggests a structural reorganization or an exchange of the bismuth polycations as mechanisms of cluster formation. In this top‐down approach a complex‐structured unit formed at high temperature was made available for low‐temperature use. 相似文献
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Bismuthinite (Bi2S3) nanostructures were prepared by a hydrothermal method with sodium ethylenediaminetetraacetate (EDTA‐Na2). The morphology of Bi2S3 nanostructures was changed from a nanorod to a nanoplate by presence of the EDTA‐Na2. The altered morphology was caused by the capping effect of EDTA‐Na2 with Bi3+ ions, which induces the suboptimal growth direction due to partially blocking the preferential orientation direction. When the EDTA‐Na2/Bi3+ molar ratio=1, the growth of Bi2S3 nanostructures was not allowed due to the chelating effect of EDTA‐Na2. The obtained Bi2S3 nanorods, stacked nanorods, nanoplates and nanoparticles were characterized using X‐ray diffraction (XRD), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) pattern. A possible formation mechanism of these morphologies was proposed. The successful synthesis of various morphologies of nanostructured Bi2S3 may open up new possibilities for thermoelectric, electronic and optoelectronic uses of nanodevices based on Bi2S3 nanostructure. 相似文献
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2-取代-4(3H)-喹唑啉酮在Br(o)nsted酸性功能化离子液体中的微波合成 总被引:3,自引:0,他引:3
以N-甲基咪唑、吡啶为起始原料,合成了二种新型Br(o)nsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6 min即可完成,产率81%~95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变. 相似文献
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Liu Z Liang J Li S Peng S Qian Y 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(3):634-640
This article describes a facile solvothermal method by using mixed solvents for the large-scale synthesis of Bi(2)S(3) nanoribbons with lengths of up to several millimeters. These nanoribbons were formed by a solvothermal reaction between Bi(III)-glycerol complexes and various sulfur sources in a mixed solution of aqueous NaOH and glycerol. HRTEM (high-resolution transmission electron microscopy) and SAED (selective-area electron diffraction) studies show that the as-synthesized nanoribbons had predominately grown along the [001] direction. The Bi(2)S(3) nanoribbons prepared by the use of different sulfur sources have a common formation process: the initial formation of NaBiS(2) polycrystals, which serve as the precursors to Bi(2)S(3), the decomposition of NaBiS(2), and the formation of Bi(2)S(3) seeds in the solution through a homogeneous nucleation process; the growth of Bi(2)S(3) nanoribbons occurs at the expense of NaBiS(2) materials. The growth mechanism of millimeter-scale nanoribbons involves a special solid-solution-solid transformation as well as an Ostwald ripening process. Some crucial factors affect nanoribbon growth, such as, solvothermal temperature, volume ratio of glycerol to water, and the concentration of NaOH; these have also been discussed. 相似文献
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用微波辐射法,合成了5个含有机膦氧基团的离子液体:1-丙基-3-(3-二苯基氧膦基)丙基咪唑双(三氟甲基磺酰基)亚胺盐([PImC3P(O)Ph2][Tf2N])、1-己基-3-(3-二苯基氧膦基)丙基咪唑双(三氟甲基磺酰基)亚胺盐([HImC3P(O)Ph2][Tf2N])、1-丙基-3-(3-苯基乙氧基氧膦基)丙基咪唑双(三氟甲基磺酰基)亚胺盐([PImC3P(O)Ph(OEt)][Tf2N])、1-己基-3-(3-苯基乙氧基氧膦基)丙基咪唑双(三氟甲基磺酰基)亚胺盐([HImC3P(O)Ph(OEt)][Tf2N])和(3-苯基乙氧基氧膦基)丙基三乙胺双(三氟甲基磺酰基)亚胺盐([TENC3P(O)Ph(OEt)][Tf2N])。 用31P NMR、1H NMR、13C NMR、MS及FT-IR对产物结构进行了表征。 研究了这类离子液体对稀土Nd(III)的萃取性能。 结果表明,这类功能化离子液体可作为单一组分萃取稀土而无需加入有机稀释剂,离子液体结构对萃取效率影响很大,相同条件下季铵盐型结构的离子液体[TENC3P(O)Ph(OEt)][Tf2N]对稀土Nd(Ⅲ)的萃取效率最高。 稀土溶液pH值对萃取效率影响显著,近中性条件下(pH=6.63),对稀土Nd(Ⅲ)的萃取率最高。 用pH=1.00的盐酸溶液可以较好的从离子液体相反萃Nd(Ⅲ),反萃率可达94%。 相似文献
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Ivan Guryanov Dr. Francesca Maria Toma Dr. Alejandro Montellano López Dr. Mauro Carraro Dr. Tatiana Da Ros Dr. Guido Angelini Dr. Eleonora D'Aurizio Dr. Antonella Fontana Prof. Michele Maggini Prof. Maurizio Prato Prof. Marcella Bonchio Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(46):12837-12845
The effect of microwave (MW) irradiation and ionic liquids (IL) on the cycloaddition of azomethine ylides to [60]fullerene has been investigated by screening the reaction protocol with regard to the IL medium composition, the applied MW power, and the simultaneous cooling of the system. [60]Fullerene conversion up to 98 % is achieved in 2–10 min, by using a 1:3 mixture of the IL 1‐methyl‐3‐n‐octyl imidazolium tetrafluoroborate ([omim]BF4) and o‐dichlorobenzene, and an applied power as low as 12 W. The mono‐ versus poly‐addition selectivity to [60]fullerene can be tuned as a function of fullerene concentration. The reaction scope includes aliphatic, aromatic, and fluorous‐tagged (FT) derivatives. MW irradiation of IL‐structured bucky gels is instrumental for the functionalization of single‐walled carbon nanotubes (SWNTs), yielding group coverages of up to one functional group per 60 carbon atoms of the SWNT network. An improved performance is obtained in low viscosity bucky gels, in the order [bmim]BF4> [omim]BF4> [hvim]TF2N (bmim=1‐methyl‐3‐n‐butyl imidazolium; hvim=1‐vinyl‐3‐n‐hexadecyl imidazolium). With this protocol, the introduction of fluorous‐tagged pyrrolidine moieties onto the SWNT surface (1/108 functional coverage) yields novel FT‐CNS (carbon nanostructures) with high affinity for fluorinated phases. 相似文献