- Dynamic viscosities of a series of 1-alkyl-3-methylimidazolium chloride ionic liquids and their binary mixtures with water at several temperatures
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Dynamic viscosities, densities, and refractive indices have been measured from T = 298.15 K to T = 343.15 K for 1-hexyl-3-methylimidazolium chloride, [C6mim][Cl], and 1-methyl-3-octylimidazolium chloride, [C 8mim]-[Cl]. Dynamic viscosities and densities have been determined over the whole composition range for water + [C6mim][Cl] and water + [C8mim][Cl] at T = (298.15, 313.15, 328.15, and 343.15) K and 0.1 MPa of pressure. Excess molar volumes and viscosity deviations for the binary systems at the above-mentioned temperatures were fitted to a Redlich-Kister equation to determine the fitting parameters and the root mean square deviations. Densities and viscosities of water + 1-butyl-3-methylimidazolium chloride, [C4mim][Cl], at T= (298.15, 313.15, 328.15, and 343.15) K and 0.1 MPa of pressure have been measured, and apparent molar volumes were determined.
- Gomez, Elena,Gonzalez, Begona,Dominguez, Angeles,Tojo, Emilia,Tojo, Jose
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- An efficient, eco-friendly, one-pot protocol for the synthesis of 2-oxazolines promoted by ionic liquid/indium chloride
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2-Oxazolines have been synthesized using a solventless ionic liquid melt in good yields at ambient temperatures. The efficiency of various Lewis acid catalysts for the same reaction has been compared. The effectiveness of different alkyl chains in the ionic liquids for the synthesis of oxazolines has been studied and a butylmethylimidazolinium chloride/indium chloride melt has been found to be the best media for promoting the reaction. CSIRO 2006.
- Kamakshi,Reddy, Boreddy S.R.
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- Adsorption of arsenic from aqueous solution using a zero-valent iron material modified by the ionic liquid [Hmim]SbF6
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The environmental and health impacts caused by arsenic (As) in wastewater make it necessary to carefully manage As wastes. In the present work, a composite of the ionic liquid [Hmim]SbF6and nano-iron (H/Fe) was used as an adsorbent to remove As(v) from aqueous solution. To better understand the removal effect of H/Fe on As(v) in aqueous solution, the reaction parameters of pH, reaction temperature, time and H/Fe dosage were systematically analyzed in detail. The results show that H/Fe has significant removal efficiency toward As(v), and that the adsorption of As(v) by 0.5 g H/Fe reaches its maximum adsorption capacity within 2 h. The adsorption of As(v) on H/Fe is a non-linear, time-varying process. The initial adsorption reaction is fast; however, unlike at the beginning, the later reaction involves sustained slow absorption, resulting in a distinct two-phase adsorption characteristic. Redox reaction may be one of the mechanisms responsible for the slow adsorption of As(v) on H/Fe. At the same time, the As(v) removal effect of H/Fe is greatly restricted by the pH. Electrostatic adsorption, adsorption co-precipitation and redox reactions act together on H/Fe in the As(v) removal process. This study provides a basis for further clarifying the adsorption, adsorption rules and mechanism of As(v) on H/Fe and a feasible method for the improvement of As(v) removal efficiency of zero-valent iron materials.
- Wu, Fenghui,Zhao, Chenyang,Qu, Guangfei,Yan, Zhoupeng,Zeng, Yingda,Chen, Bangjin,Hu, Yinghui,Ji, Wei,Li, Yingli,Tang, Huimin
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- Determination of thermal diffusivities, thermal conductivities, and sound speeds of room-temperature ionic liquids by the transient grating technique
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We report measurements of thermal diffusivity of several room-temperature ionic liquids (RTILs) using the transient grating method. Measurements are carried out using ionic liquids with small concentrations of an inert dye that is excited by the 532 nm output of a Nd:YAG laser in a grating with a fringe spacings of (92 and 104) μm. The experiments give thermal diffusivities from which thermal conductivities can be determined, sound speeds, and acoustic damping parameters for seven ionic liquids. In this study, we have used combinations of the cation 1-butyl-3-methylimidazolium ([BMIm]+) with the anions tetrafluoroborate ([BF4]-), hexafluorophosphate ([PF6]-), and bis(trifluoromethylsulfonyl)imide ([Tf2N]-) and combinations of the anion [Tf2N]- with the cations 1-ethyl-3-methylimidazolium ([EMIm]+), 1-pentyl-3-methylimidazolium ([PMIm]+), 1-hexyl-3-methylimidazolium ([HMIm]+), and 1-octyl-3-methylimidazolium ([OMIm]+) to determine the effect of anion and cation on the thermophysical properties of the RTILs. Results obtained indicate that the anion exerts a strong influence not only on the sound speed but also on the thermal diffusivity and acoustic damping of the RTILs. For RTILs with the same cation [BMIm]+, changing the anion from [BF 4]- to either [PF6]- or [Tf 2N]- leads to decreases in the sound speed, thermal diffusivity, and thermal conductivity. The size of the cation, however, does not significantly influence the sound speed or the thermal diffusivity of the RTILs.
- Frez, Clifford,Diebold, Gerald J.,Tran, Chieu D.,Yu, Shaofang
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- Solution enthalpies of ionic liquid 1-hexyl-3-methylimidazolium chloride
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The molar enthalpies of solution of ionic liquid (IL) [C 6mim][Cl] (1-hexyl-3-methylimidazolium chloride) at various molalities in water were measured by a solution-reaction isoperibol calorimeter at 298.15 K. According to Pitzer's electrolyte solution theory, the molar standard enthalpy of solution of [C6mim][Cl], Δ solHm0 and Pitzer's parameters, βMX(0)L, β;MX(1)L, and CMXφL, were obtained. In terms of the experimental data in literature, the mean contribution per methylene (-CH2-) group to the standard molar enthalpies of solution of [Cxmim][Cl] is discussed.
- Fang, Da-Wei,Sun, Ying-Chun,Wang, Zhen-Wei
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- Measurement of high-pressure densities and atmospheric viscosities of ionic liquids: 1-hexyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide and 1-Hexyl-3-methylimidazolium chloride
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Atmospheric densities and viscosities of ionic liquids, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C 6C1Im][Tf2N]) and 1-hexyl-3-methylimidazolium chloride ([C6C1Im][Cl]), were measured with a Stabinger viscometer at temperatures from (293 to 373) K. High-pressure densities (p ≤ 200 MPa) for [C6C1Im][Tf2N] and [C 6C1Im][Cl] were measured with a bellows type apparatus at temperatures from (312 to 452) K. Samples were analyzed for the water and 1-methylimidazole content before and after the measurements. For [C 6C1Im][Tf2N], combined expanded uncertainties were estimated to be (1.0 and 1.8) kg·m-3 for atmospheric and high-pressure density, respectively, and 0.85 % for viscosity. For [C 6C1Im][Cl], combined expanded uncertainties were estimated to be (1.1 and 2.5) kg·m-3 for atmospheric and high-pressure density, respectively, and 1.59 % for viscosity. The measured densities and viscosities of [C6C1Im][Tf2N] in this work agreed with some of the available literature values within their experimental uncertainties. The effect of colored impurities and the source of sample on densities and viscosities of [C6C1Im][Cl] were determined to be less than the experimental uncertainties. The [C6C 1Im][Tf2N] did not decompose over the full temperature range during the measurements, while [C6C1Im][Cl] decomposed at temperatures greater than 392 K.
- Iguchi, Masayuki,Hiraga, Yuya,Sato, Yoshiyuki,Aida, Taku Michael,Watanabe, Masaru,Smith Jr., Richard L.
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- Properties and catalytic activity of magnetic and acidic ionic liquids: Experimental and molecular simulation
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The exploitation of dual functional magnetic and acidic ionic liquids (MAILs) for hydrolysis of cellulose to platform chemicals can solve some practical challenges through easy separation of products and efficient catalyst recyclability. In this work, seven Cnmim/FeCl4 MAILs were synthesized and investigated with combined experimental and molecular dynamics. The MAILs contained FeCl4- anions and exhibited a typical hard magnetic materials behavior with rather strong magnetic susceptibilities. These MAILs were stable up to 250-310 C, the decomposition was started up at 250/310-480-810 C in two steps with the formation of the undecomposed residue. The Gibbs energy for the reaction of glucose/xylose conversion to 5-hydroxymethylfurfural by metal chlorides in the CnmimCl ionic liquid was studied using the density functional theory calculations and the results that C3mim/WCl3 may be the most hopeful catalyst. The MAILs have the potential to open up promising new catalytic systems because of their easy product separation and efficient catalyst recyclability.
- Zhou, Cunshan,Yu, Xiaojie,Ma, Haile,Huang, Xingyi,Zhang, Henan,Jin, Jian
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- Photophysical properties of lanthanide (Eu 3+, Tb 3+) hybrid soft gels of double functional linker of ionic liquid-modified silane
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Four kinds of luminescent hybrid soft gels have been assembled by introducing the lanthanide (Eu3+, Tb3+) tetrakis β-diketonate into the covalently bonded imidazolium-based silica through electrostatic interactions. Here, the imidazolium-based silica matrices are prepared from imidazolium-derived organotriethoxysilanes by the sol-gel process, in which the imidazolium cations are strongly anchored within the silica matrices while anions can still be exchanged following application for functionalization of lanthanide complexes. The photoluminescence measurements indicated that these hybrid soft gels exhibit characteristic red and green luminescence originating from the corresponding ternary lanthanide ions (Eu 3+, Tb3+). Further investigation of photophysical properties reveals that these soft gels have inherited the outstanding luminescent properties from the lanthanide tetrakis β-diketonate complexes such as strong luminescence intensities, long lifetimes and high luminescence quantum efficiencies. Ternary lanthanide luminescent hybrid soft gels Gel-Im+[LaL4]- were prepared by linking the europium/terbium tetrakis β-diketonate complexes into the silicon framework, which provides a representative method to assemble lanthanide-functionalized porous materials with chemical bonds.
- Li, Qiu-Ping,Yan, Bing
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- Phase diagram data for several salt + salt aqueous biphasic systems at 298.15 K
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Phase diagrams corresponding to aqueous biphasic systems of salt (the organic ionic liquid of salts [C4min]Cl, [C6mim]Cl, and [C8mim]Cl) + salt (K3PO4, K2CO 3) + water were deter
- Deng, Yuefeng,Chen, Ji,Zhang, Dongli
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- Hydrogels dispersed by doped rare earth fluoride nanocrystals: Ionic liquid dispersion and down/up-conversion luminescence
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Two typical kinds of rare earth fluoride nanocrystals codoped with rare earth ions (Eu3+ and Tm3+/Er3+,Yb3+) are synthesized and dispersed in ionic liquid compound (1-chlorohexane-3- methylimidazolium chloride, abbreviated as [C6mim][Cl]). Assisted by agarose, the luminescent hydrogels are prepared homogeneously. The down/up-conversion luminescence of these hydrogels can be realized for the dispersed rare earth fluoride nanocrystals. The results provide a strategy to prepare luminescent (especially up-conversion luminescent) hydrogels with ionic liquid to disperse rare earth fluoride nanocrystals.
- Yan, Zhi-Yuan,Jia, Li-Ping,Yan, Bing
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- Infrared spectroscopic study of absorption and separation of CO using copper(i)-containing ionic liquids
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Absorption of carbon monoxide by copper(i)-containing ionic liquids, [Cnmim][CuX2] (Cnmim = 1-alkyl-3-methylimidazolium, n = 2, 4, 6, X = Cl, Br, I) has been investigated using in situ high pressure infrared spectroscopy. For each liquid, observation of a ν(CO) band in the region 2075-2090 cm-1 indicates the formation of copper(i) monocarbonyl complexes, assigned as [Cu(CO)X2]-. The rate of growth and equilibrium intensity of the ν(CO) absorption is dependent on applied CO pressure. Binding of CO is reversible such that complete desorption occurs rapidly on heating above 100 °C and the liquids are robust over multiple gas absorption/desorption cycles. For the series of [C6mim][CuX2] salts the CO absorption ability follows the order Cl ≥ Br> I. Selective absorption of CO from CO/H2 and CO/N2 gas mixtures is demonstrated by measuring the changes in headspace CO content upon absorption and desorption of gas. For [C6mim][CuCl2], a single absorb-vent-desorb cycle yields product gas containing ～95% CO starting from a 1:1 CO/N2 mixture, increasing to ～98% CO starting from a 4:1 CO/N2 mixture. This is particularly promising in view of the similar boiling points of CO and N2 that hinders their separation by cryogenic distillation.
- Repper, Stephen E.,Haynes, Anthony,Ditzel, Evert J.,Sunley, Glenn J.
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- Dicyanoaurate(I) salts with 1-alkyl-3-methylimidazolium: Luminescent properties and room-temperature liquid forming
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Room-temperature ionic liquids containing dicyanoaurate(I) anions were prepared utilizing 1-alkyl-3-methylimidazolium cations, and display luminescence possibly due to the oligomerization of the significant fraction of Au(CN) 2 anions in the li
- Yoshida, Yukihiro,Fujii, Junichi,Saito, Gunzi,Hiramatsu, Takaaki,Sato, Naoki
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- Liquid-liquid interfacial tension of equilibrated mixtures of ionic liquids and hydrocarbons
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Ionic liquids are possible alternative solvents for the separation of aromatic and aliphatic hydrocarbons by liquid-liquid extraction. Interfacial tension is an important property to consider in the design of liquid-liquid extraction processes. In this work, the liquid-liquid interfacial tension and the mutual solubility at 25 °C have been measured for a series of biphasic, equilibrated mixtures of an ionic liquid and a hydrocarbon. In particular, the ionic liquids 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (with the alkyl substituent being ethyl, hexyl or decyl), 1-ethyl-3- methylimidazolium ethylsulfate, and 1-ethyl-3-methylimidazolium methanesulfonate have been selected, as well as the hydrocarbons benzene, hexane, ethylbenzene, and octane. The selected sets of ionic liquids and hydrocarbons allow the analysis of the influence of a series of effects on the interfacial tension. For example, the interfacial tension decreases with an increase in the length of the alkyl substituent chain of the cation or with an increase of the degree of charge delocalisation in the anion of the ionic liquid. Also, the interfacial tension with the aromatic hydrocarbons is markedly lower than that with the aliphatic hydrocarbons. A smaller effect is caused by variation of the size of the hydrocarbon. Some of the observed trends can be explained from the mutual solubility of the hydrocarbon and the ionic liquid. Science China Press and Springer-Verlag Berlin Heidelberg 2012.
- Rodriguez, Hector,Arce, Alberto,Soto, Ana
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- Synthesis, structure, and physico-optical properties of manganate(II)-based ionic liquids
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Several ionic liquids (ILs) based on complex manganate(II) anions with chloro, bromo, and bis(trifluoromethanesulfonyl)amido (Tf2N) ligands have been synthesized. As counterions, n-alkyl-methylimidazolium (C nmin) cations of different chain length (alkyl = ethyl (C 2), propyl (C3), butyl (C4), hexyl (C 6)) were chosen. Except for the 1-hexyl-3-methylimidazolium ILs, all of the prepared compounds could be obtained in a crystalline state at room temperature. However, each of the compounds displayed a strong tendency to form a supercooled liquid. Generally, solidification via a glass transition took place below -40°C. Consequently, all of these compounds can be regarded as ionic liquids. Depending on the local coordination environment of Mn 2+, green (tetrahedrally coordinated Mn2+) or red (octahedrally coordinated Mn2+) luminescence emission from the 4T(G) level is observed.[1] The local coordination of the luminescent Mn2+ centre has been unequivocally established by UV/Vis as well as Raman and IR vibrational spectroscopies. Emission decay times measured at room temperature in the solid state (crystalline or powder) were generally a few ms, although, depending on the ligand, values of up to 25 ms were obtained. For the bromo compounds, the luminescence decay times proved to be almost independent of the physical state and the temperature. However, for the chloro- and bis(trifluoromethanesulfonyl)amido ILs, the emission decay times were found to be dependent on the temperature even in the solid state, indicating that the measured values are strongly influenced by nuclear motion and the vibration of the atoms. In the liquid state, the luminescence of tetrahedrally coordinated Mn2+ could only be observed when the tetrachloromanganate ILs were diluted with the respective halide ILs. However, for [C3mim][Mn(Tf2N)3], in which Mn 2+ is in an octahedral coordination environment, a weak red emission from the pure compound was found even in the liquid state at elevated temperatures.
- Pitula, Slawomir,Mudring, Anja-Verena
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- Enhanced antimicrobial activities of 1-alkyl-3-methyl imidazolium ionic liquids based on silver or copper containing anions
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We have developed a series of 1-alkyl-3-methylimidazolium tetrachlorocuprate(ii) and dibromoargentate(i) ionic liquids with enhanced antimicrobial activity when compared with 1-alkyl-3-methylimidazolium chloride ionic liquids. These new ionic liquids proved to be effective against a range of pathogenic bacteria and fungi.
- Gilmore, Brendan F.,Andrews, Gavin P.,Borberly, Gabor,Earle, Martyn J.,Gilea, Manuela A.,Gorman, Sean P.,Lowry, Andrew F.,McLaughlin, Martin,Seddon, Kenneth R.
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- Solvent-free sonochemical preparation of ionic liquids.
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[reaction: see text] An ultrasound-assisted preparation of a series of ambient-temperature ionic liquids, 1-alkyl-3-methylimidazolium (AMIM) halides, which proceeds via efficient reaction of 1-methyl imidazole with alkyl halides/terminal dihalides under solvent-free conditions, is described.
- Namboodiri, Vasudevan V,Varma, Rajender S
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- Crystalline and liquid crystalline organic-inorganic hybrid salts with cation-sensitized hexanuclear molybdenum cluster complex anion luminescence
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The salts [Cnmim]2[Mo6Cl14] (mim = methylimidazolium; n = 4, 6, 12, 16, 18) have been obtained by reaction of CnmimCl with MoCl2. Thermal analysis shows the melting point decreases with increasing alkyl chain length of the cation. The imidazolium chloromolybdates(II) with n = 6-18 decompose above 340 °C; [C18mim]2[Mo6Cl14] is thermally stable up to 390 °C. All compounds are insensititve to the constituents of the atmosphere. Of the higher melting salts [Cnmim] 2[Mo6Cl14] (n = 4, 6), high-quality single crystals could be obtained. Single-crystal X-ray structural analyses clearly show that the cluster complex anion [Mo6Cl14]2- has an electron-precise octahedral {Mo6} cluster. For [C 4mim]2[Mo6Cl14], two polymorphs differing in the cation alkyl-side-chain conformation were obtained. The less thermodynamically stable modification with a gauche conformation undergoes monotropic phase transition to the more stable form with the all-trans conformation. Long alkyl-side-chain salts, [Cnmim] 2[Mo6Cl14] with n = 16 and 18, exhibit thermotropic liquid-crystalline behaviour. All compounds show bright red luminescence centred at about 730 nm with a lifetime of about 0.15 ms, originating from the cluster complex anion, which can be sensitized by the imidazolium cations.
- Baecker, Joanna,Mihm, Svenja,Mallick, Bert,Yang, Mei,Meyer, Gerd,Mudring, Anja-Verena
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- Antibiofilm activities of 1-alkyl-3-methylimidazolium chloride ionic liquids
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Microbial biofilms are ubiquitous in nature and represent the predominant mode of growth of microorganisms. A general characteristic of biofilm communities is that they tend to exhibit significant tolerance to antimicrobial challenge compared with planktonic bacteria of the same species The antibiofilm activity of a series of 1-alkyl-3-methylimidazolium chloride ionic liquids has been evaluated against a panel of clinically significant microbial pathogens, including MRSA. A comparison of antimicrobial activity against planktonic bacteria and established biofilms is presented. In general, these ionic liquids possess potent, broad spectrum antibiofilm activity.
- Carson, Louise,Chau, Peter K. W.,Earle, Martyn J.,Gilea, Manuela A.,Gilmore, Brendan F.,Gorman, Sean P.,McCann, Maureen T.,Seddon, Kenneth R.
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- Densities, excess molar and partial molar volumes for water + 1-butyl- or, 1-hexyl- or, 1-octyl-3-methylimidazolium halide room temperature ionic liquids at T = (298.15 and 308.15) K
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Experimental densities for seven mixtures of water + 1-butyl-3- methylimidazolium iodide, [C4mim][I], + 1-hexyl-3-methylimidazolium chloride, [C6mim][Cl], + 1-hexyl-3-methylimidazolium bromide, [C 6mim][Br], + 1-hexyl-3-me
- Sastry, Nandhibatla V.,Vaghela, Nilesh M.,Macwan, Pradip M.
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- Densities and viscosities of binary mixtures of magnetic ionic liquids 1-alkyl-3-methylimidazolium tetrachloroferrate with ethyl acetate at temperatures (293.15 to 323.15) K
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The physicochemical properties of the binary mixtures of magnetic ionic liquids (MILs) are essential for industrial process designs of their applications. In this work, three MILs were synthesized and characterized, including 1-butyl-3-methylimidazolium tetrachloroferrate ([Bmim][FeCl4]), 1-hexyl-3-methylimidazolium tetrachloroferrate ([Hmim][FeCl4]) and 1-octyl-3-methylimidazolium tetrachloroferrate ([Omim][FeCl4]). Densities and viscosities of binary mixtures of these MILs with ethyl acetate (EA) were determined over the whole range of compositions at temperatures (293.15 to 323.15) K at 5 K intervals. The data of densities as a function of temperature were fitted with linear equation and viscosities were correlated with Vogel–Fucher–Tammann (VFT) equation. Results showed that the densities and viscosities of the binary mixtures decreased significantly with the IL concentration decreasing and with temperature increasing. Excess molar volumes (VE) and viscosity deviations (Δη) were calculated and fitted well with the Redlich-Kister equation. The negative VE and Δη over the entire composition range indicated that there were stronger interactions between MILs and EA than those among MILs and among EA.
- Li, Xiaohua,Zhou, Qing,Lu, Xingmei,Zhang, Suojiang
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- Lonization state and ion migration mechanism of room temperature molten dialkylimidazolium fluorohydrogenates
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The ionization state of room temperature molten salts, alkylimidazolium fluorohydrogenates (RMIm-(HF)2.3F: R = alkyl group, M =methyl group), was evaluated from the observed diffusion coefficient and viscosity, using the Stokes-Einstein relation. Assuming that the dissociation degree of the salt is acceptable for representation of the ionic state of the molten salts, the larger the cation size with elongation of the alkyl chain was, the higher the dissociation degree of the salt Further, we proposed that an idea of the "degree of ordering of cations and anions" was more suitable to represent the ionization state without solvent species. On the basis of this idea, the smaller the cation size of RMIm(HF)2.3F salt was, the higher the ordering of the ion, indicating formation of domain particles of aggregated ions as a unit of mobile species such as A(AX)m + and X(AX)n- for A+X- salt. It was found that highly ordered particles, with large numbers for m and n, showed a high diffusion coefficient. ? 2005 American Chemical Society.
- Saito, Yuria,Hirai, Kenichi,Matsumoto, Kazuhiko,Hagiwara, Rika,Minamizaki, Yoshihiro
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- An expeditious solvent-free route to ionic liquids using microwaves
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A microwave-assisted preparation of a series of ambient temperature ionic liquids, 1-alkyl-3-methylimidazolium (AMIM) halides, that proceeds via efficient reaction of 1-methylimidazole with alkyl halides/terminal dihalides under solvent-free conditions, is described.
- Varma,Namboodiri
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- Thermodynamic evaluation of imidazolium based ionic liquids with thiocyanate anion as effective solvent to thiophene extraction
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In order to have deep insight on the molecular interactions between thiophene (TS) and ionic liquids, the density, speed of sound and refractive index of binary liquid mixture of TS with 1-hexyl-3-methylimidazolium thiocyanate [HMIM][SCN], and 1-octyl-3-m
- Shekaari, Hemayat,Zafarani-Moattar, Mohammed Taghi,Niknam, Mehrdad
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- Purification of imidazolium ionic liquids for spectroscopic applications
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Ionic liquids are often contaminated by colored impurities. These impurities can be problematic for spectroscopic studies or for monitoring organic reactions by UV/Vis spectroscopy. The effect of different purification methods on the optical quality of colored ionic liquids was studied and compared. Yellowish ionic liquids can partially be decolorized by treatment with active charcoal or by recrystallization. Our experiments show column liquid chromatography is not always a good technique to prepare spectrograde imidazolium halide ionic liquids. Colorless and UV-transparent ionic liquids were synthesized by a method that can exclude the need for further purification steps.
- Nockemann, Peter,Binnemans, Koen,Driesen, Kris
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- Transition-metal- and phosphorus-free electrophilic trifluoromethylthiolation of indoles with sodium trifluoromethanesulfinates in ionic liquids
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An acid-promoted protocol has been developed to achieve the transition-metal- and phosphorus-free electrophilic trifluoromethylthiolation of indoles using sodium trifluoromethanesulfinates in an imidazolium-based ionic liquid ([Hmim]Br). [Hmim]Br not only acts as a recyclable solvent, but also as the reductant in this transformation. The advantages of this chemistry include simple operation, use of a recyclable solvent, avoidance of transition-metal and phosphorus, and gram-scale synthesis.
- Wang, Fei,Lu, Guo-Ping,Lin, Yamei
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supporting information
(2021/04/12)
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- Various metal organic frameworks combined with imidazolium, quinolinum and benzothiazolium ionic liquids for removal of three antibiotics from water
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In this research, imidazolium, quinolinum and benzothiazolium based ionic liquids (ILs) were immobilized on a metal organic framework (MOF) by solvent impregnation or capillary action. The synthesized IL@MOF composite materials were characterized by FTIR, XRD, SEM and TGA methods and then applied in removal of tetracyclines (TCs) from aqueous samples. The presence of ionic liquids significantly improved the adsorption efficiency of the metal organic framework, with 82% or higher removal percentage was obtained for the three target TCs while the pristine MOFs adsorption efficiency was below 50%. This could be attributed to the ability of ILs to make complex interaction with target drugs via multiple intermolecular forces. Experimental results revealed the effects of three significant factors including pH, temperature and solid-liquid ratio, and optimum adsorption efficiency could be achieved at pH 8 and 30 °C when solid-liquid ratio = 1:2 was adopted. The adsorption kinetics was properly fitted with pseudo-second order model and Redlich-Peterson model could be used to describe the adsorption isotherm for three antibiotics; moreover, the adsorption was an endothermic and spontaneous process in nature. Finally, the adsorbed TCs could be desorbed efficiently and the performance of the IL@MOF sorbent was further verified by actual water samples.
- Yohannes, Alula,Li, Jing,Yao, Shun
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- The one-pot synthesis of butyl-1H-indol-3-alkylcarboxylic acid derivatives in ionic liquid as potent dual-acting agent for management of BPH
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Based on the SAR of both α1-AR antagonists and 5α-reductase (5AR) inhibitors, the dual-acting agent 4-(1-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-1H-indol-3-yl)butanoic acid 4aaa was designed against BPH and synthesized by two steps of N-alkylation. One-pot protocol towards 4aaa was newly developed. With IL [C6min]Br as solvent, the yield of 4aaa was increased to 75.1% from 16.0% and the reaction time was shortened in 1.5 h from 48 h. 25 derivatives structurally based on arylpiperazine and indolyl butyric acid with alkyl linker were prepared. The protocol was futher extended to get another 14 derivatives wherein O-alkylation was involved, and applied to the synthesis of biologically efficient molecules DPQ and Aripiprazole. Expectedly, compound 4aaa exhibited dual inhibition of α1-AR and 5α-reductase, and exhibited no obvious cytotoxicity against human cells. The pharmacokinetic properties of 4aaa was also determined.
- Chen, Kaixuan,Jiang, Zhenzhou,Liu, Shuwen,Xi, Baomin,Yang, Fubiao,Zeng, Li-Yan,Zeng, Yunong
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- Ionic Liquids Catalyzed Friedel–Crafts Alkylation of Substituted Benzenes with CCl4 Toward Trichloromethylarenes
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Abstract: An ionic liquid catalyzed Friedel–Crafts alkylation reaction of substituted benzenes with CCl4 was developed. The reaction proceeded efficiently under mild conditions, gave corresponding trichloromethylarenes with diversity functional groups in moderate to good yields. The influence of Lewis acidity of ionic liquids on the conversion of the alkylation reaction has been investigated. Notably, the probable mechanism of this reaction has been proposed with the assistance of 27Al NMR spectroscopy. It was noteworthy that the predominance of [Al2Cl7]? species in EmimCl–AlCl3, N = 0.67 could be detected by 27Al NMR spectral analysis, and [AlCl4]? was generated at the beginning of reaction. Additionally, it was found that [AlCl4]? could be transformed into [Al2Cl7]? when the reaction finished. Some control experiments confirmed that the interaction between Lewis acidic species [Al2Cl7]? of the ionic liquid and CCl4 led to the change in speciation of aluminum during the alkylation reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Lyu, Xinyu,Wang, Wencheng,Sun, Yiqun,Zhao, Qian,Qiu, Tao
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p. 665 - 671
(2019/01/04)
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- Acid-induced chemoselective arylthiolations of electron-rich arenes in ionic liquids from sodium arylsulfinates: The reducibility of halide anions in [Hmim]Br
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An acid-induced protocol for the chemoselective arylthiolations of electron-rich arenes in ionic liquids from sodium arylsulfinates is introduced. The chemistry, in which [Hmim]Br (heaxylmethylimidazolium bromide) is used as both a solvent and a reducer, provides several advantages including odorless and simple operation, inexpensive reagents, recyclable solvents and gram-scale synthesis.
- Xu, Zhu-Bing,Lu, Guo-Ping,Cai, Chun
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p. 2804 - 2808
(2017/04/04)
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- 1,3-Dialkylimidazolium modified clay sorbents for perchlorate removal from water
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Sodium montmorillonite clays modified using 1-alkyl-3-methylimidazolium based ionic liquids with varying alkyl chain length viz. C4, C6, C8, C10 and C16 were used for perchlorate adsorption from water. Pristine MMT showed negligible adsorption whereas ionic liquid modified clays showed an increase in adsorption with increase in chain length of the exchanged cation. 1-Hexadecyl-3-methylimidazolium modified clay (C16-clay) with a d-spacing of 18.55 A showed a maximum adsorption of 0.16 mmol g-1 of clay. The d-spacing of the C16-clay decreased on adsorption of perchlorate to 13.70 A without a change in the composition of the modified clay, as confirmed by CHN analysis. Raman spectroscopic studies substantiated the conformational change from gauche to trans for the imidazolium cations on perchlorate adsorption. The adsorption followed the Freundlich isotherm with pseudo second order kinetics. The modified clays were thermally stable (200 °C) and regenerated by heating to 175 ± 5 °C in air and 95% regenerability was observed.
- Thomas, Eapen,Rekha, Krishnan G.,Bhuvaneswari, Soundiraraju,Vijayalakshmi, Kunduchi P.,George, Benny K.
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p. 80029 - 80036
(2017/04/03)
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- Schiff base ligands and their transition metal complexes in the mixtures of ionic liquid + organic solvent: A thermodynamic study
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Schiff bases and their metal complexes in the mixtures of ionic liquid (IL) + organic solvent have shown great potential in attractive oxidation catalytic processes. The efficiency of such a process is strongly dependent on the various molecular interactions occurring between components. Thermodynamic properties of these systems can provide valuable information about structural interactions. Therefore, in this work, the interactions of the IL 1-hexyl-3-methylimidazolium chloride ([HMIm]Cl) with Schiff bases in organic solvents were studied through the measurements of density, viscosity, and electrical conductivity. The effect of solvent on the interactions was examined by the solutions of IL + BPIC Schiff base + solvent (C2H6O-C3H8O-C4H10O). Moreover, the influence of Schiff base ligand and Schiff base complex structures was probed by the solutions of IL + DMA + ligand (salcn/salpr/salen) and IL + DMA + complex (VO(3-OMe-salen)/VO(salophen)/VO(salen)), respectively. Using the experimental data, some important thermodynamic properties, such as standard partial molar volume (Vf,IL0), experimental slope (Sv), viscosity B-coefficient, solvation number (B/Vf,IL0), and limiting molar conductivity (Λ0) were calculated and discussed in terms of solute-solvent (IL-DMF/alcohol) and solute-cosolute (IL-Schiff base) interactions.
- Shekaari, Hemayat,Kazempour, Amir,Khoshalhan, Maryam
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p. 2179 - 2191
(2015/02/19)
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- IONIC LIQUIDS FOR TRANSDERMAL DRUG DELIVERY
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IIONIC LIQUIDS FOR TRANSDERMAL DRUG DELIVERY ABSTRACT The compositions and methods described herein are topically applied to the skin with negligible or no skin irritation and can direct or prevent transport through the skin. The compositions contain neat ionic liquids, optionally in combination with a drug to be delivered. In a preferred embodiment, the compositions increase transdermal transport of the drug to be delivered. In some embodiments, the compositions disrupt bacterial biofilms. This is particularly beneficial in the treatment of antibiotic resistant skin infections. In other embodiments, the compositions direct delivery within the skin. In still other embodiments, the compositions prevent transfer of substances through the stratum corneum. The disclosed compositions and methods can be tuned and modified such that they can be used to treat or prevent a variety of different diseases and disorders.
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Page/Page column 20
(2015/05/19)
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- Does alkyl chain length really matter? Structure-property relationships in thermochemistry of ionic liquids
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DSC was used for determination of reaction enthalpies of synthesis of ionic liquids [Cnmim][Cl]. A combination of DSC with quantum chemical calculations presents an indirect way to study thermodynamics of ionic liquids. The indirect procedure for vaporization enthalpy was validated with the direct experimental measurements by using thermogravimetry. First-principles calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the CBS-QB3 and G3 (MP2) theory. Experimental DSC data for homologous series of alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were collected from the literature. We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies are linearly dependant on the alkyl chain length. The thermochemical properties of ILs generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization seem to be very close to those for molecular compounds.
- Verevkin, Sergey P.,Zaitsau, Dzmitry H.,Emel'Yanenko, Vladimir N.,Ralys, Ricardas V.,Yermalayeu, Andrei V.,Schick, Christoph
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- Microwave synthesis and properties of a series of N-alkyl-N-methylimidazolium chloride ionic liquids
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Seven N-alkyl-N-methylimidazolium chloride ionic liquids were synthesized under the organic-solvent-free condition with microwave irradiation. The structures were characterized and confirmed by 1H NMR and melting points were determined by differential scanning calorimetry (DSC). Their surface tensions and water adsorption properties were measured at room temperature. The results showed that there was a decrease in surface tension and water adsorption with an increasing substituting alkyl chain length in the 1-position of N of the cation. However the melting points increased with an increasing substituting alkyl chain length of the N of the cation.
- Pan,Wang,Pei
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experimental part
p. 6026 - 6030
(2010/12/19)
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- Influence of imidazolium bis(trifluoromethylsulfonylimide)s on the rotation of spin probes comprising ionic and hydrogen bonding groups
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The influence of the alkyl chain length in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide)s is studied to explore the rotation of piperidine-1-yloxyl derivatives substituted with either hydrogen bonding hydroxy group or ionic substituents, such as the cationic trimethylammonium or the anionic sulfate group placed at the 4 position. Structural variation of the ionic liquids results in differences of their viscosity influencing the rotation of the spin probes. The size of the average rotational correlation times of the spin probes dissolved in the ionic liquids depends further on the additional substituent in 4-position at these spin probes. The rotational correlation time exhibits a linear dependence on the ionic liquid viscosity in the case of the spin probe forming hydrogen bonding with the ionic liquids. In contrast to this, a deviation from the Stokes-Einstein behavior is found in the case of rotation of the charged spin probes in the 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide)s substituted with a longer alkyl chain. This effect may be explained by phase separation on a molecular level between the charged part of the ionic liquid and the longer alkyl chains bound at the imidazolium ion. Although the neutral and the cationic spin probes show only a slight dependence between ionic liquid structure variation and the hyperfine coupling constants, structural effects cause changes in the hyperfine coupling constants in the case of the anionic spin probes. These probes strongly interact with the imidazolium ion.
- Strehmel, Veronika,Rexhausen, Hans,Strauch, Peter
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experimental part
p. 1933 - 1940
(2010/09/05)
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- Conductivities of binary mixtures of ionic liquids with polar solvents
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Data for the conductivity, κ, of selected binary mixtures of the ionic liquids [emim][BF4], [bmim][BF4], [bmim][PF 6], [brmm][DCA], and [hmim][BF4] with polar solvents (water, propylene carbonate, dimethyl-sulfoxide, methanol, dichloromethane) at 25 °C are reported. Additionally, mixture densities, p, were determined to convert κ into molar conductivity, A. The obtained results were fitted by appropriate interpolation formulas. Where possible, data were compared with information from the literature. Electrode polarization and sample purity, including [BF4-] hydrolysis, were considered as possible sources of errors in κ. The effect of viscosity on the accuracy of p and thus A was checked.
- Stoppa, Alexander,Hunger, Johannes,Buchner, Richard
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experimental part
p. 472 - 479
(2010/04/05)
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- Improved 1-butene/isobutane alkylation with acidic ionic liquids and tunable acid/ionic liquid mixtures
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A new process for 1-butene/isobutane alkylation to yield C 8-alkylates is described using binary mixtures of certain acidic imidazolium ionic liquids (ILs) and strong acids such as sulfuric or trifluoromethanesulfonic (triflic) acid. Equivalent or better conversion (>95%), C8-alkylates selectivity (>70%) and trimethylpentane/ dimethylhexane selectivity (TMP/DMH > 7) were achieved with the IL/acid mixtures over the pure acids themselves. Six types of substituted 3-methyl-imidazolium ionic liquids were investigated, wherein acidity is imparted via either the cation with sulfonic acid groups or the anion (hydrogen sulfate) or both. Long-term studies up to 30+ recycles indicate that the catalyst stability was increased by sometimes greater than 30+% with the IL/acid mixtures over the pure acid. The ionic liquid is believed to tune the acidity, solubility, and interfacial properties, resulting in these enhanced results. In addition, this concept could also be applicable to Friedel-Crafts alkylation, acylation chemistries, or other acid-catalyzed reactions.
- Tang, Shengwei,Scurto, Aaron M.,Subramaniam, Bala
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experimental part
p. 243 - 250
(2011/05/07)
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- Kinetic study of thermal Z to e isomerization reactions of azobenzene and 4-dimethvlaniino-4′-nitroazobenzene in Ionic Liquids [1-R-3- methyliniidazolium bis(trifluoromethylsulfonyl)imide with R = Butyl, Pentyl, and Hexyl]
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Thermal Z to E isomerization reactions of azobenzene and 4-dimethylamino-4′-nitroazobenzene were examined in three ionic liquids of general formula 1-R-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (R = butyl, pentyl. and hexyl). The first-order rate constants and activation energies for the reactions of azobenzene measured in these ionic liquids were consistent with those measured in ordinary organic solvents, which indicated that the slow isomerization through the inversion mechanism with a nonpolar transition state was little influenced by the solvent properties, such as the vis cosity and dielectric constant, of ionic liquids. On the other hand, the rate constants and the corresponding frequency factors of the Arrhenius plot were significantly reduced for the isomerization of 4-dimethylamino-4′- nitroazobenzene in ionic liquids compared with those for the isomerization in ordinary organic molecular solvents with similar dielectric properties. Although these ionic liquids are viscous, the apparent viscosity dependence of the rate constant could not be explained either by the Kramers-Grote-Hynes model or by the Agmon-Hopfield model for solution reactions. It is proposed that the positive and the negative charge centers of a highly polar rotational transition state are stabilized by the surrounding anions and cations, respectively, and that the ions must be rearranged so as to form highly ordered solvation shells around the charge centers of the reactant in the transition state. This requirement for the orderly solvation in the transition state results in unusually small frequency factors of 104-107 s -1.
- Baba, Keita,Ono, Hajime,Itoh, Eri,Itoh, Sumitaka,Noda, Kyoko,Usui, Toshinori,Ishihara, Koji,Inamo, Masahiko,Takagi, Hideo D.,Asano, Tsutomu
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p. 5328 - 5333
(2008/02/12)
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- The HF/BF3-catalysed reaction of substituted benzenes with carbon monoxide
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The HF/BF3-catalysed reactions of phenol and anisole as well as substituted benzenes with CO were investigated as possible routes to commercially important aldehydes. The results confirmed that HF and BF 3 are required in (at least) stoichiometric amounts for effective formylation with CO. With the aim of effecting truly catalytic reaction conditions, the formylation reactions were carried out in ionic liquids. It was shown that phenol is a good substrate for formylation in certain ionic liquids. Georg Thieme Verlag Stuttgart.
- Willemse, J. Alexander,Bezuidenhoudt, Barend C. B.,Holzapfel, Cedric W.
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p. 2543 - 2550
(2008/02/04)
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- An in-depth look at the effect of Lewis acid catalysts on Diels-Alder cycloadditions in ionic liquids
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The present work explores in detail the Diels-Alder reaction between cyclopentadiene and a series of dienophiles, performed in an innovative medium such as an ionic liquid. The potential activation of different Lewis acid catalysts and their load effect when used in combination with this solvent have been explored, in order to settle the improvement on rates and selectivities.
- Silvero, Guadalupe,Arévalo, María José,Bravo, José Luis,ávalos, Martín,Jiménez, José Luis,López, Ignacio
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p. 7105 - 7111
(2007/10/03)
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- Organic salt conditioner, organic salt-containing composition, and uses thereof
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The present invention relates to the use of, and a composition containing, at least one non-polymeric organic salt with a melting point of less than 60° C. These organic salts may be imidazolium, pyrazolium, pyridinium, pyrimidinium or tetraalkylphosphonium salts. The inventinon composition may be used for washing (cleaning) and/or conditioning keratin materials, and especially the hair.
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- Separation of olefins from paraffins using ionic liquid solutions
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Methods for separating olefins from non-olefins, such as parafins, including cycloparaffins, oxygenates and aromatics, are provided. The methods use metal salts to complex olefins, allowing the non-olefins to be separated by a variety of methods, including decantation and distillation. The metal salts are dissolved in ionic liquids, which tend to have virtually no vapor pressure, and which poorly solubilize the non-olefins. Accordingly, the non-olefins phase separate well, and can be distilled without carrying over any of the ionic liquid into the distillate. Preferred salts are Group IB salts, more preferably silver salts. A preferred silver salt is silver tetrafluoroborate. Preferred ionic liquids are those which form stable solutions or dispersions of the metal salts, and which do not dissolve the non-olefins. Further, if the olefins are subject to isomerization, the ionic liquid is preferably relatively non-acidic. The methods involve forming a solution of a suitable olefin-complexing salt in an appropriate ionic liquid. An olefin-containing mixture is contacted with the ionic liquid/salt solution, and the olefins are adsorbed. After the paraffins are removed, the olefins can be isolated by desorption. The olefin-containing mixture can be in the gas phase, or in the liquid phase. The flow of olefin-containing mixtures over/through the ionic liquid can be, for example, co-current, counter-current, or staged in stirred tanks. Countercurrent is preferred as it is the most efficient. The methods can be optimized using combinatorial chemistry.
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Page column 9
(2008/06/13)
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- Alkylation process
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This invention relates to a process for the alkylation of aromatics by reacting an aromatic hydrocarbon with an olefin in the presence of an ionic liquid comprising (a) a compound of the formula Rn MX3-n wherein R is a C1-C6 alkyl radical, M is aluminium or gallium, X is a halogen atom and n is 0, 1 or 2 and, (b) a hydrocarbyl substituted imidazolium halide or a hydrocarbyl substituted pyridinium halide wherein at least one of the said hydrocarbyl substituents in the imidazolium halide is an alkyl group having 1-18 carbon atoms. The process allows ready separation of reaction products from the ionic liquid and improves selectivity to alkylated products.
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