离子液体催化1-丁烯齐聚反应

用AlCl3、FeCl3与溴化1-烷基-3-甲基咪唑盐([Rmim]Br)合成酸性离子液体,用于催化1-丁烯齐聚反应,考察反应温度、催化剂用量、反应时间、反应压力及催化剂阴阳离子物质的量比对齐聚产物选择性的影响.结果表明,以[C4mim]Br-FeCl3为催化体系效果较佳.在室温、催化剂用量2.0 g、反应时间2 h、...     

Solubility of light alkanes and alkenes in ionic liquids

The solubility of light hydrocarbons in a variety of ionic liquids was studied, and it was found that ionic liquids containing Cu(Ⅰ) had higher solubility for hydrocarbons and alkene/alkane solubility selectivity, and Et₃NHCl-2.1CuCl ionic liquid was preferred. The effects of temperature and pressure on the solubility of light hydrocarbons were investigated for the selected ionic liquid. It was found that low temperature and high pressure were favorable for the dissolution of light hydrocarbons, and the alkene/alkane solubility selectivity decreased with the increase of temperature and pressure. The alkene/alkane solubility selectivity was above 8.3 at the temperature of 30℃ and the pressure of 0.2 MPa. The initial dissolution rate of hydrocarbons in ionic liquid was large, but it decreased rapidly with prolonging time, and the dissolution rate of alkenes was higher than that of alkanes at the same conditions. The alkene/alkane separation selectivity increased with decreasing content of alkenes in the mixture of alkenes and alkanes. Light hydrocarbons dissolved in ionic liquids could be desorbed by means of increasing temperature, restoring the dissolution capability of ionic liquids to hydrocarbons. Alkanes were easier to be desorbed than alkenes, and small-molecule hydrocarbons were easier to be desorbed than large-molecule hydrocarbons. The desorption percentage exceeded 92% under optimal conditions. Ionic liquid had a good reusable performance in the absorption and separation of light alkanes and alkenes. The solubility only decreased by less than 5% when it was reused five times, and the alkane/alkane solubility selectivity was basically not affected by reusing times. Software Gaussian 09 was used to study the interaction between anions of ionic liquids and light alkanes and alkanes, and the solubility difference of light alkenes and alkanes in different ionic liquids was well explained.     

小分子烷烃与烯烃在离子液体中的溶解性能

研究了多种离子液体对小分子烃类的溶解性能,发现含有Cu(Ⅰ)的离子液体对烃类具有较高的溶解度和烯烃/烷烃溶解选择性,优选出了Et₃NHCl-2.1CuCl离子液体。考察了温度和压力对小分子烃类溶解性能的影响规律,发现低温和高压有利烃类的溶解,烯烃/烷烃溶解选择性随温度和压力的升高而减小;在30℃和0.2 MPa的条件下,烯烃/烷烃溶解选择性均在8.3以上。烃类在离子液体中的初始溶解速率较大,但随时间的延长快速降低,相同条件下烯烃的溶解速率高于烷烃的溶解速率。烯烃/烷烃分离选择性随混合气中烯烃含量的减小而增大。升温可以解吸出离子液体中的烃类,烷烃比烯烃容易解吸,优化条件下的解吸率可达92%以上。离子液体对小分子烷烃和烯烃的吸收分离具有良好的重复使用性能。利用Gaussian 09软件对离子液体的阴离子与烯烃、烷烃的作用进行了计算分析,解释了烯烃和烷烃在不同离子液体中溶解性能差异的原因。     

Dehydration of Benzyl Alcohols in Phosphonium Ionic Liquids: Synthesis of Ethers and Alkenes

The dehydration of benzylic alcohols has been studied in several phosphonium ionic liquids in the absence of any metal catalysts. Benzyl ethers and alkenes were obtained from primary and secondary benzylic alcohols in good to excellent yields for these reactions. Commercially available hydrophobic phosphonium ionic liquids containing the trihexyl(tetradecyl)phosphonium cation paired with six different anions were used for the reactions under microwave irradiation. The interaction of the substrate with the ionic liquid was investigated using different NMR techniques, such as NOESY NMR. The effects of cation and anions on the behaviour of these ionic liquids in the reactions were studied in order to understand the mechanism. A catalytic cycle is proposed involving activation of the benzyl alcohol by the phosphonium cation.     

Group contribution methods for the prediction of thermophysical and transport properties of ionic liquids

Thermophysical and transport properties of ionic liquids are required for the design of processes and products. Yet the experimental data available are scarce and often contradictory. Based on experimental data collected from the literature, group contribution methods were developed for the estimation of viscosity, electrical conductivity, thermal conductivity, refractive index, isobaric expansivity, and isothermal compressibility, of various families of ionic liquids. Using the Stokes–Einstein relation a correlation for the self‐diffusion coefficients with the viscosity is also proposed. The results of the proposed models show average absolute relative deviations generally of the same order of the experimental accuracy of the data. They are easy to use and can provide predictions of property values for ionic liquids never previously studied. The group contribution basis of these models will allow them to be extended to new groups of cations and anions as further data became available. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

基于COSMO-RS模型的分离油酚混合物的离子液体萃取剂筛选

低温煤焦油中酚类化合物的分离对其充分利用具有重要意义。基于COSMO-RS模型,以间甲酚和异丙苯作为模型化合物,研究了离子液体在分离油酚体系中的应用;利用Turbomole软件建立了包含27种离子液体阴离子和48种离子液体阳离子的s-图谱数据库,结合COSMOtherm软件对组成的1296种离子液体进行筛选,探讨了阴阳离子对间甲酚分离效果的影响,并对筛选得到适宜的离子液体进行液液相平衡实验验证。结果表明,离子液体阴离子对间甲酚分离效果影响较大,以Cl^-和CH₃COO^-为阴离子的离子液体与间甲酚之间具有较强的氢键相互作用,因此具有较好的分离效果;阳离子对间甲酚分离效果影响较小,碳链或支链的增加能适当提高离子液体对间甲酚的分离效果。实验得到的bmimOAc、bmimCl、emimOAc、TPAC四种离子液体-间甲酚-异丙苯的液液相平衡数据表明,四种离子液体对间甲酚均具有较大的分配系数和选择性,且萃取分离效果的顺序为：emimOAc > bmimOAc > TPAC > bmimCl,与COSMO-RS模拟筛选得到的结果一致,表明筛选具有较高的准确性。     

Swelling behaviors of natural cellulose in ionic liquid aqueous solutions

In the study, a series of methylimidazolium ionic liquids were prepared, including five acidic and seven neutral ionic liquids; and the effects of these ionic liquids on swelling behavior of bagasse cellulose were investigated. The focus of this work is to investigate the relationship between the properties of ionic liquids and the swelling capacity. The swelling absorbency for cellulose in the acidic ionic liquid aqueous solutions was less than in distilled water. It was found that the partial hydrolysis on cellulose surface occurred along with swelling simultaneously. In neutral ionic liquid aqueous solutions, the nonlinearity of swelling ability with the alkyl chain length was discovered. It could be attributed to the dual role of hydrophobic interactions and steric effects provided by cations. Furthermore, small polarizable anions also contribute to the swelling of cellulose to some extent. The properties of treated cellulose were also investigated and compared with the native fibers by scanning electron microscopy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40199.     

Chemical–physical properties of bis(perfluoroalkylsulfonyl)imide-based ionic liquids

The chemical–physical properties of hydrophobic ionic liquids, tailored as electrolyte components for supercapacitors and lithium batteries, were investigated and compared. The ionic liquid samples are based on bis(perfluroalkylsulfonyl)imide anions coupled with different types of cation. The effect of the cation as well as the main cationic aliphatic side group, in combination with different anions, on the chemical–physical properties of the investigated ionic liquid samples was evaluated and discussed. The activation energy for the conduction mechanism and the glass transition temperature were obtained by fitting the conductivity vs. temperature data.     

离子液体的合成

离子液体作为一类新型的环境友好的。绿色溶剂”,具有很多独特的性质,在很多领域有着诱人的应用前景。本文主要介绍了以N,N’-二烷基咪唑阳离子,N-烷基吡啶阳离子与含氟阴离子,氯酸铝阴离子等形成的室温离子液体的合成方法。     

Physical and electrochemical properties of room-temperature dicyanamide ionic liquids based on quaternary phosphonium cations

The physicochemical and electrochemical properties of room temperature ionic liquids based on quaternary phosphonium cations together with a dicyanamide anion are presented in this report. The most dicyanamide-based phosphonium ionic liquids prepared were hydrophilic, except ionic liquids containing a long alkyl chain in the phosohonium cation. It was found that asymmetric phosphonium cations gave low-melting salts in combination with a dicyanamide anion. The dicyanamide-based phosphonium ionic liquids exhibited relatively low viscosities and high conductivities when compared to those of the corresponding ammonium ionic liquids. Particularly, the ionic liquids containing a methoxy group in the phosphonium cations indicated very low viscosities. Comparatively good electrochemical stability of the dicyanamide-based phosphonium ionic liquids was confirmed by voltammetric measurements. The thermogravimetric analysis suggested that the dicyanamide-based phosphonium ionic liquids showed higher thermal stability than those of the corresponding ammonium ionic liquids, indicating an improving effect of the phosphonium cations on the thermal stability.     

基于COSMO-RS方法筛选离子液体分离乙酸乙酯-乙腈共沸物

采用COSMO-RS方法探究了不同离子液体在分离乙酸乙酯-乙腈共沸物系中的应用;通过预测值与实验值的对比,验证了COSMO-thermX预测离子液体分离效果的准确性。离子液体的选择性和不同离子液体对乙酸乙酯-乙腈近沸点处相对挥发度的影响为指标,计算和分析了17种阳离子和13种阴离子组成的221种离子液体对乙酸乙酯-乙腈共沸物系的分离效果的影响规律。结果表明,含有[OAc]^－和[Cl]^－的离子液体对于乙酸乙酯-乙腈混合物的分离具有更好的促进效果,而阳离子的变化对于乙酸乙酯-乙腈混合物分离的促进效果差异较小。应用表面电荷密度分布（σ-profile）进一步研究了阴离子[OAc]^－和[Cl]^－对共沸物的影响,研究发现,阴离子[OAc]^－和[Cl]^－对乙酸乙酯-乙腈的分离效果影响顺序为[OAc]^－>[Cl]^－;综合筛选结果,得出离子液体[BMIM][OAc]有望在乙酸乙酯-乙腈共沸混合物分离过程中成为一种高效的萃取剂。     

金属有机骨架固载离子液体复合材料研究进展

离子液体是一种由阴离子和阳离子共同组成的有机熔融盐，其挥发性低、热稳定性和化学稳定性好、电化学窗口宽、结构可调变，近年来在诸多领域具有广泛的应用。但由于其黏度大不便于输送和操作，合成成本较高、回收利用率低等缺点，其发展受到了一定的限制。金属有机骨架 (MOFs) 材料是由金属离子/团簇和有机配体通过配位键自组装形成的具有分子内孔隙结构的有机-无机杂化材料。以MOFs为载体固载离子液体，不仅可以保留离子液体的优势，还可以赋予离子液体而很多新的特性。本文从MOFs固载离子液体的理论计算和实验应用研究出发，综述了MOFs固载离子液体的起源和固载方式，分析了MOFs和离子液体之间的兼容性、固载形式和相互作用，并对MOFs固载离子液体的瓶颈问题进行了分析，对发展方向进行了展望。     

Influence of ionic liquids on the growth ofEscherichia coli

Ionic liquids are compounds that composed only of ions and are liquid at room temperature. Thus, it is normally named room temperature ionic liquid (RTIL). In this study, the application of RTILs to the extractive fermentation of biomaterials was investigated as a substitute of organic solvents. The relative toxicity of the RTILs on the growth ofE. coli was tested. The inhibition of cell growth in the presence of various ionic liquids was measured using solid and liquid culture, and EC₅₀ of each RTILs was calculated. The number of viable and total cells was measured by the number of colonies and optical density, respectively. Effective concentrations of toxicity (EC₅₀) in these tested systems were similar with conventional solvents, such as acetone, acetonitrile, and ethanol. The viability ofE. coli was affected by the polarity and ionic properties of ionic liquids. The resistance of the microorganisms against ionic liquids was different with the cations and anions composing ionic liquids. No general influence of the anionic compound of the ionic liquids was found on toxicity comparing with distinctive influence of cationic moiety.     

离子液体在有机反应中的应用

室温离子液体,由含氮的有机阳离子和无机阴离子组成,由于离子液体是很多化合物的溶剂,也能够溶解作为催化剂的过渡金属络合物,其阴离子还是潜在的配位体,故它们能起催化剂的功能,本文着重讨论这方面的发展状况。     

己内酰胺类离子液体的热力学性质(英文)

A series of caprolactam ionic liquids(ILs) containing incorporated halide anions were synthesized.Their physical properties,such as melting points,heats of fusion and heat capacities,were measured by differential scanning calorimeter(DSC).The results indicate that these ionic liquids exhibit proper melting points,high value of heats of fusion,and satisfying heat capacities which are suitable for thermal energy storage applications.     

Thermodynamic Properties of Caprolactam Ionic Liquids

A series of caprolactam ionic liquids (ILs) containing incorporated halide anions were synthesized. Their physical properties, such as melting points, heats of fusion and heat capacities, were measured by differential scanning calorimeter (DSC). The results indicate that these ionic liquids exhibit proper melting points, high value of heats of fusion, and satisfying heat capacities which are suitable for thermal energy storage applications.     

Polymeric ionic liquids: Broadening the properties and applications of polyelectrolytes

The introduction of new ionic moieties, cations and anions, is extending the properties and classical applications of polyelectrolytes. These new polyelectrolytes are being named polymeric ionic liquids (PILs) in analogy to their monomeric constituents (i.e. cations such as imidazolium, pyridinium, pyrrolidonium and anions such as hexafluorophosphate, triflates, amidotriflates). This is giving rise to a new family of functional polymers with particular properties and new applications. The first part of this review will focus on the synthetic aspects of PILs and the main aspects related to their physico-chemical properties. In the second part we will review the new technological applications of these polymers such as polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive materials, smart surfaces, and a countless set of applications in different fields such as energy, environment, optoelectronics, analytical chemistry, biotechnology or catalysis.     

咪唑类离子液体性质、制备及应用的研究进展

简介了离子液体的种类、性质,重点阐述了咪唑类离子液体的制备及其应用,通过对离子液体进行阴阳离子的设计得到功能化离子液体,主要将其作为绿色溶剂应用于有机合成反应、催化反应和萃取分离过程。     

X-ray diffraction studies of electrochemical graphite intercalation compounds of ionic liquids

Electrochemical intercalation studies are used to characterize a series of ionic liquids composed of a variety of cationic and anionic species. Electrochemically, the ionic liquids are characterized by cyclic voltammograms and charge–discharge experiments for the intercalation and de-intercalation of the various cationic and anionic species into graphite. X-ray structure analysis is also performed to determine the relationship between the electrochemical behaviour of the ionic liquids, and the formation of intercalated graphitic compounds. Two different types of imidazolium cations are studied, specifically the di- and trisubstituted imidazolium. These cations are paired with the following anions: tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, bis(perfluoroethanesulfonyl)imide, nitrate and hydrogen sulfate. Results indicate stronger intercalation chemistry for the trisubstituted imidazoliums, correlating with the greater charge–discharge efficiencies found for these types of ionic liquids. Many of the anions exhibit very poor charge–discharge efficiencies, correlating to very poorly formed graphite intercalates. The exception to this is the hydrogen sulfate intercalate, which had low charge–discharge efficiencies but formed a well defined graphite intercalate. Only the imide based anions exhibited both high charge–discharge efficiencies and the formation of a clearly defined graphite intercalate.     

Accounting for the unique, doubly dual nature of ionic liquids from a molecular thermodynamic and modeling standpoint

The fascinating, complex behavior of ionic liquids is analyzed using a molecular perspective that emphasizes the doubly dual nature of ionic liquids underlying the existence of cations and anions forming high- and low-charge-density regions. Our work bridges the liquid, gas, and solid phases spanning 5 years of research on themes as diverse as the vaporization, liquid-liquid demixing, solidification, and thermophysical behavior of ionic liquids and their mixtures and solutions.