- Physical properties of 1-butyl-3-methylimidazolium methyl sulfate as a function of temperature
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Density, speed of sound, refractive index, dynamic viscosity, and surface tension measurements of 1-butyl-3-methylimidazolium methyl sulfate have been made as a function of temperature. The synthesis of the ionic liquid is given. The low viscosity of the ionic liquid suggests its use as a solvent in the extraction process for the separation of azeotropic mixtures. The thermal expansion coefficient of the ionic liquid was calculated from the density, and the results are discussed. An analysis of the influence of the alkyl chain length of the cation on the density was performed by comparison with recently published values.
- Pereiro, Ana B.,Verdia, Pedro,Tojo, Emilia,Rodriguez, Ana
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- Synthesis and characterization of physicochemical properties of imidazolium-based ionic liquids and their application for simultaneous determination of sulfur compounds
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Three types of imidazolium-based ionic liquids (IMILs) were synthesized and characterized by 13C and 1H NMR, FT-IR, and elemental analysis. Thermal stability and physicochemical properties of prepared IMILs were measured in the temperature range of 283.15 to 363.15 K. The physicochemical results revealed the entirely temperature-dependent properties and quietly decreasing through increasing the temperature. Electrochemical studies of the IMILs were also performed at the surface of screen-printed electrode cells. Consideration of these properties and determining the unique abilities of IMILs will help researchers through modern applications like liquid-liquid extraction, particular tasks of scavenging and removal of hydrogen sulfide and thiols from petroleum matrices.
- Shoja, Seyed Mohammad Reza,Abdouss, Majid,Beigi, Ali Akbar Miran
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- Synthesis method of 1-butyl-3-methylimidazole tetrafluoroborate ionic liquid
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The invention discloses a synthesis method of a 1-butyl-3-methylimidazole tetrafluoroborate ionic liquid. The method comprises the following steps: with N-butylimidazole and dimethyl sulfate as raw materials, carrying out a reaction in a pressure reactor to obtain an intermediate 1-butyl-3-methylimidazole methyl sulfate; and reacting the obtained intermediate 1-butyl-3-methylimidazole methyl sulfate with sodium tetrafluoroborate in a pressure reaction container, and carrying out filtering and concentrating to obtain the 1-butyl-3-methylimidazole tetrafluoroborate ionic liquid. The method has the advantages of simple process steps, strong operability, no generation of solid wastes in the synthesis process, environmental protection and high product yield.
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Paragraph 0022-0024
(2020/06/02)
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- METHOD FOR GENERATING OXYGEN FROM COMPOSITIONS COMPRISING IONIC LIQUIDS
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The present invention is directed to a method for generating oxygen comprising providing at least one oxygen source, providing at least one ionic liquid, providing at least one metal oxide compound, wherein the oxygen source is a peroxide compound, the ionic liquid is in the liquid state at least in the temperature range from ?10° C. to +50° C., and the metal oxide compound is an oxide of one single metal or of two or more different metals, said metal(s) being selected from the metals of groups 2 to 14 of the periodic table of the elements, and contacting the oxygen source, the ionic liquid, and the metal oxide compound.
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- A quick, simple, robust method to measure the acidity of ionic liquids
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Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of -1 to -9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe.
- Gr?svik, John,Hallett, Jason P.,To, Trang Quynh,Welton, Tom
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supporting information
p. 7258 - 7261
(2014/07/07)
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- Are alkyl sulfate-based protic and aprotic ionic liquids stable with water and alcohols? A thermodynamic approach
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The knowledge of the chemical stability as a function of the temperature of ionic liquids (ILs) in the presence of other molecules such as water is crucial prior to developing any industrial application and process involving these novel materials. Fluid phase equilibria and density over a large range of temperature and composition can give basic information on IL purity and chemical stability. The IL scientific community requires accurate measurements accessed from reference data. In this work, the stability of different alkyl sulfate-based ILs in the presence of water and various alcohols (methanol, ethanol, 1-butanol, and 1-octanol) was investigated to understand their stability as a function of temperature up to 423.15 K over the hydrolysis and transesterification reactions, respectively. From this investigation, it was clear that methyl sulfate- and ethyl sulfate-based ILs are not stable in the presence of water, since hydrolysis of the methyl sulfate or ethyl sulfate anions to methanol or ethanol and hydrogenate anion is undoubtedly observed. Such observations could help to explain the differences observed for the physical properties published in the literature by various groups. Furthermore, it appears that a thermodynamic equilibrium process drives these hydrolysis reactions. In other words, these hydrolysis reactions are in fact reversible, providing the possibility to re-form the desired alkyl sulfate anions by a simple transesterification reaction between hydrogen sulfate-based ILs and the corresponding alcohol (methanol or ethanol). Additionally, butyl sulfate- and octyl sulfate-based ILs appear to follow this pattern but under more drastic conditions. In these systems, hydrolysis is observed in both cases after several months for temperatures up to 423 K in the presence of water. Therein, the partial miscibility of hydrogen sulfate-based ILs with long chain alcohols (1-butanol and 1-octanol) can help to explain the enhanced hydrolytic stability of the butyl sulfate- and octyl sulfate-based ILs compared with the methyl or ethyl sulfate systems. Additionally, rapid transesterification reactions are observed during liquid-liquid equilibrium studies as a function of temperature for binary systems of (hydrogen sulfate-based ionic liquids + 1-butanol) and of (hydrogen sulfate-based ionic liquids + 1-octanol). Finally, this atom-efficient catalyst-free transesterification reaction between hydrogen sulfate-based ILs and alcohol was then tested to provide a novel way to synthesize new ILs with various anion structures containing the alkyl sulfate group. ? 2013 American Chemical Society.
- Jacquemin, Johan,Goodrich, Peter,Jiang, Wei,Rooney, David W.,Hardacre, Christopher
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p. 1938 - 1949
(2013/04/23)
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- Correlation between hydrogen bond basicity and acetylene solubility in room temperature ionic liquids
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Room temperature ionic liquids (RTILs) are proposed as the alternative solvents for the acetylene separation in ethylene generated from the naphtha cracking process. The solubility behavior of acetylene in RTILs was examined using a linear solvation energy relationship based on Kamlet-Taft solvent parameters including the hydrogen-bond acidity or donor ability (α), the hydrogen-bond basicity or acceptor ability (β), and the polarity/polarizability (π*). It is found that the solubility of acetylene linearly correlates with β value and is almost independent of α or π*. The solubility of acetylene in RTILs increases with increasing hydrogen-bond acceptor (HBA) ability of the anion, but is little affected by the nature of the cation. Quantum mechanical calculations demonstrate that the acidic proton of acetylene specifically forms hydrogen bond with a basic oxygen atom on the anion of a RTIL. On the other hand, although C-H???π interaction is plausible, all optimized structures indicate that the acidic protons on the cation do not specifically associate with the π cloud of acetylene. Thermodynamic analysis agrees well with the proposed correlation: the higher the β value of a RTIL is, the more negative the enthalpy of acetylene absorption in the RTIL is.
- Palgunadi, Jelliarko,Hong, Sung Yun,Lee, Jin Kyu,Lee, Hyunjoo,Lee, Sang Deuk,Cheong, Minserk,Kim, Hoon Sik
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experimental part
p. 1067 - 1074
(2011/06/19)
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- The effect of the ionic liquid anion in the pretreatment of pine wood chips
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The effect of the anion of ionic liquids on air-dried pine (Pinus radiata) has been investigated. All ionic liquids used in this study contained the 1-butyl-3-methylimidazolium cation; the anions were trifluoromethanesulfonate, methylsulfate, dimethylphosphate, dicyanamide, chloride and acetate. Using a protocol for assessing the ability to swell small wood blocks (10 × 10 × 5 mm), it was shown that the anion has a profound impact on the ability to promote both swelling and dissolution of biomass. Time course studies showed that viscosity, temperature and water content were also important parameters influencing the swelling process. We used Kamlet-Taft parameters to quantify the solvent polarity of the ionic liquids and found that the anion basicity described by the parameter β correlated with the ability to expand and dissolve pine lignocellulose. It is shown that 1-butyl-3-methylimidazolium dicyanamide dissolves neither cellulose nor lignocellulosic material.
- Brandt, Agnieszka,Hallett, Jason P.,Leak, David J.,Murphy, Richard J.,Welton, Tom
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supporting information; experimental part
p. 672 - 679
(2010/08/22)
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- METHOD FOR PRODUCING ONIUM ALKYL SULFATES WITH A LOW HALOGENIDE CONTENT
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The invention relates to a method for producing onium alkyl sulfates by reacting an onium halogenide with a symmetrically substituted dialkyl sulfate, the alkyl group thereof containing between 1 and 14 C atoms, with an unsymmetrically substituted dialkyl sulfate, one alkyl group containing between 4 and 20 C atoms, and the second alkyl group being methyl or ethyl, with an alkyl-trialkylsilyl sulfate, with an alkylacyl sulfate, or with an alkylsulfonyl sulfate, the reaction with the dialkyl sulphate taking place at room temperature.
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Page/Page column 29
(2008/06/13)
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- Lipase-catalyzed enantioselective acylation in a halogen free ionic liquid solvent system
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Lipase-catalyzed enantioselective transesterification was demonstrated using several types of imidazolium alkyl sulfate as a reaction medium. The desired optically pure acetate was successfully obtained under the conditions used, although reaction rate was inferior to that in imidazolium tetrafluoroborate.
- Itoh, Toshiyuki,Ouchi, Nozomi,Hayase, Shuichi,Nishimura, Yoshihito
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p. 654 - 655
(2007/10/03)
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- Halogenide-free preparation of ionic fluids
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Preparation of ionic liquids (I) involves alkylating an amine, phosphine, imidazole, pyridine, triazole or pyrazole corresponding to the cation of (I) with a sulfate diester (II), then replacing the sulfate anion by the anion of (I). Preparation of ionic liquids of formula (I) involves alkylating the amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation A, with a sulfate diester of formula (II), then replacing the sulfate anion R4SO4 or R5SO4 by the anion Yn-. (An).(Yn-) (I) R4SO2R5 (II) n = 1 or 2; Yn- = BF4, BCl4, PF6, SbF6, AsF6, AlCl4, ZnCl3, CuCl2, SO4, CO3, R'COO, R'SO3 or (R'SO2)2N; R' = 1-12C linear, branched or cyclic alkyl, 5-18C aryl, (5-18C) aryl-(1-6C) alkyl or (1-6C) alkyl-(5-18C) aryl (all optionally halo-substituted); A = NR1R2R3R or PR1R2R3R; or 1-(R)-3-(R1)-imidazolium, (R1)-substituted 1-(R)-pyridinium, 1-(R)-2-(R1)-pyrazolium or 1-(R)-1,3,5-triazolium (all optionally ring-substituted by one or more of 1-6C alkyl, 1-6C alkoxy, 1-6C aminoalkyl, 5-12C aryl or (5-12C) aryl-(1-6C) alkyl); R1-R3 = H; 1-20C linear, branched or cyclic alkyl; Het or Het-(1-6C) alkyl; or Ar or Ar-(1-6C) alkyl; R, R4, R5 = 1-24C linear, branched or cyclic alkyl; Het-(1-6C) alkyl; or Ar'-(1-6C) alkyl; Het = heteroaryl containing 3-8C and at least one of N, O and S (optionally substituted by one or more of 1-6C alkyl and halo); Ar = 5-12C aryl (optionally substituted by one or more of 1-6C alkyl and halo); and Ar' = 5-24C aryl (optionally substituted by one or more of 1-6C alkyl and halo).
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