共查询到20条相似文献,搜索用时 703 毫秒
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近年来碱性离子液体的设计、合成及应用获得广泛关注. 离子液体碱性表征对于碱性离子液体的应用具有重要意义. 然而, 关于碱性离子液体碱性表征深入研究的报道还比较少. 我们合成了系列碱性离子液体, 利用电位滴定法测定了碱性离子液体的pKb值, 通过相应pKb值来表征离子液体的碱性强度, 最后考察了离子液体碱性与其结构之间的关联关系. 结果表明, 羧酸根碱性离子液体的碱性主要由阴离子决定, 但不同的阳离子也会影响到其碱性强度, 从而对离子液体的碱性进行微调; 对于胺基功能化的咪唑型离子液体, 由于离子液体结构中咪唑阳离子具有较强的吸电子诱导效应, 相对于对应的三乙胺其碱性显著下降. 相似文献
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二苯醚烷基化反应中酸性离子液体的循环使用 总被引:3,自引:0,他引:3
使用酸性离子液体催化二苯醚与十二烯烷基化反应,考察了离子液体的失活原因,提出了循环使用离子液体的解决办法.在二苯醚与十二烯烷基化反应中, Lewis酸性离子液体不能多次循环使用的原因是离子液体与二苯醚相互作用导致具有催化活性的Al2Cl72-分解、流失.改变离子液体的阳离子不能从本质上解决其与二苯醚间的相互作用.适时补加损失量的AlCl3使离子液体的Lewis酸性得以恢复,可以解决体系中酸性离子液体循环使用问题,循环使用8次后产物产率仍保持90%左右. 相似文献
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设计新型液液两相催化体系:π配体离子液体 总被引:6,自引:0,他引:6
π配体催化剂与离子液体体系相结合有助于解决反应效率、产物分离和催化剂循环等一系列均相催化体系不易解决的难题. 近几年相关的研究逐渐深入,由简单地使用离子液体作为π配体催化反应的介质向利用离子液体自身结构的方向发展,相继出现了几类不同的研究思路. 例如,利用π配体催化剂与离子液体形成络合物,使用离子型π配体改善催化剂在离子液体中的溶解性,以及合成功能化阳离子或功能化阴离子的π配体离子液体. 本文结合这几类离子液体化学键联π配体(简称π配体离子液体)的研究进展,从离子液体功能化设计的角度探讨了π配体离子液体的合成思路,为设计具有更好催化性能的功能化离子液体体系提供借鉴. 相似文献
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Hasan Tanvir Imam Vladimír Krasan Martin Rebro Andrew Craig Marr 《Molecules (Basel, Switzerland)》2021,26(16)
Ionic liquids have unique chemical properties that have fascinated scientists in many fields. The effects of adding ionic liquids to biocatalysts are many and varied. The uses of ionic liquids in biocatalysis include improved separations and phase behaviour, reduction in toxicity, and stabilization of protein structures. As the ionic liquid state of the art has progressed, concepts of what can be achieved in biocatalysis using ionic liquids have evolved and more beneficial effects have been discovered. In this review ionic liquids for whole-cell and isolated enzyme biocatalysis will be discussed with an emphasis on the latest developments, and a look to the future. 相似文献
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超临界CO2/离子液体体系 总被引:2,自引:0,他引:2
超临界CO2和离子液体是两种具有优异性能的绿色化学试剂,本文介绍了将两者结合反应,分离体系的物化性质和多种绿色化学过程。利用超临界CO2可以广泛地萃取离子液体中的不挥发性化合物而不导致离子液体及其中催化剂的流失,在加氢、醛化、甲酰化等反应,分离过程中的应用表明,过程具有很好的反应分离特性和环境友好性,应用前景广阔。 相似文献
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Enantioselective chemo- and bio-catalysis in ionic liquids 总被引:2,自引:0,他引:2
Song CE 《Chemical communications (Cambridge, England)》2004,(9):1033-1043
Recent developments in the enantioselective chemo- and bio-catalysis in ionic liquids are reviewed. In many cases, the use of ionic liquids provides many advantages over reactions in conventional organic solvents in terms of activity, enantioselectivity, stability and the reusability of the solvent-catalyst systems. 相似文献
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Perkin S 《Physical chemistry chemical physics : PCCP》2012,14(15):5052-5062
Over recent years the Surface Force Apparatus (SFA) has been used to carry out model experiments revealing structural and dynamic properties of ionic liquids confined to thin films. Understanding characteristics such as confinement induced ion layering and lubrication is of primary importance to many applications of ionic liquids, from energy devices to nanoparticle dispersion. This Perspective surveys and compares SFA results from several laboratories as well as simulations and other model experiments. A coherent picture is beginning to emerge of ionic liquids as nano-structured in pores and thin films, and possessing complex dynamic properties. The article covers structure, dynamics, and colloidal forces in confined ionic liquids; ionic liquids are revealed as a class of liquids with unique and useful confinement properties and pertinent future directions of research are highlighted. 相似文献
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Ionic liquids have many unique properties as a new and remarkable class of environmental benign solvents,which promises widespread applications in industry and other areas. However,the ionic liq-uids with surface activity are rarely reported. In this work,a series of novel ionic liquids was synthe-sized by using N-methyl-2-pyrrolidone and alkyl bromide. The physical properties of this family of ionic liquids have been characterized,which shows that these compounds have ionic liquids characteristics,surface activity and biocompatibility. 相似文献
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Although many ionic liquids have been reported, their polarity is not completely understood. Different empirical polarity scales for molecular solvents always lead to different polarity orders when they are applied on ionic liquids. Based on a literature survey, this review summarizes the recent polarity scales of ionic liquids according to the following 4 classes: (1) equilibrium and kinetic rate constants of chemical reactions; (2) empirical polar parameters of ionic liquids; (3) spectral properties of probe molecules; (4) multiparameter approaches. In addition, their interrelations are presented. A systematic understanding of the relationship between different polarity parameters of ionic liquids is of great importance for finding a universal set of parameters that can be used to predict the polarities of ionic liquids quantitatively. The potential utilization of the electron paramagnetic resonance in this field is also addressed. 相似文献
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离子液体具有不挥发性、非易燃性、离子电导率高、物化性能稳定、电化学窗口宽、结构多样性与可设计性等诸多优良特性,近年来已在电化学、生物、绿色化学等领域发挥着至关重要的作用。本文综述了离子液体在生物方面的一些应用:作为理想的载体将目标基因或者药物运送到靶细胞中达到治疗的目的;探究离子液体的毒性对生物体的影响从而达到杀灭癌细胞等特殊细胞或绿色降解的目的;利用其电催化活性好、灵敏度高等特性制成生物传感器用于电化学检测;将离子液体作为核酸分离的载体,使得核酸的分离的过程简化、效率提高。 相似文献
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《Chemphyschem》2006,7(1):58-61
In addition to their stability, the advantages of air‐ and water‐stable ionic liquids over chloroaluminate ionic liquids, which were intensively investigated in the past, are that they are easy to dry, purify, and handle. Moreover, some of these ionic liquids have an extremely large electrochemical window of more than 5 V, and hence they give access to the electrodeposition of many metals and semiconductors, such as Ta, Ti, Si, and Ge. The results to date for the electrodeposition of metals and semiconductors in the most popular air‐ and water‐stable ionic liquids are presented. 相似文献
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Kobrak MN 《The Journal of chemical physics》2007,127(18):184507
The solvation dynamics of ionic liquids have been the subject of many experimental and theoretical studies but remain poorly understood. We analyze these dynamics by modeling the time-resolved fluorescence response of coumarin 153 in two room-temperature ionic liquids: 1-butyl-1-methylpyrrolidinium bromide and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide. Our results demonstrate that phenomena such as electrostatic screening operate significantly differently in the two liquids, and the relative importance of translational and rovibrational components of the ionic response depends significantly on the character of the ions involved. However, collective motion dominates the response of both ionic liquids, and the qualitative features of this collective behavior are strikingly similar in both cases. 相似文献