- Rapid, High-Yield Fructose Dehydration to 5-Hydroxymethylfurfural in Mixtures of Water and the Noncoordinating Ionic Liquid [bmim][OTf]
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The noncoordinating ionic liquid [bmim][OTf] (bmim=1-butyl-3-methylimidazolium) is an effective and versatile solvent for the high-yield dehydration of fructose to the platform chemical 5-hydroxymethylfurfural (HMF) over short reaction times. In contrast to prior studies in which low yields were obtained for this transformation in ionic liquids (ILs) with noncoordinating anions, this contribution reveals that the water content is an essential parameter for an efficient reaction in ILs. Achieving the optimum amount of water can increase the yield dramatically by regulating the acidity of the catalyst and partially suppressing the side reaction caused by self-condensation of HMF. Using acid catalysis in [bmim][OTf] with 3.5 % water content, yields above 80 % can be achieved at 100 °C in only 10 min, even at high (14 %) fructose loading. These results also suggest that [bmim][OTf] represents a superior medium for solvent extraction of HMF compared to halide-based ILs, allowing the option of isolation or further valorization of the HMF formed.
- Ghatta, Amir Al,Wilton-Ely, James D. E. T.,Hallett, Jason P.
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p. 4452 - 4460
(2019/09/06)
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- Solubilizing and Stabilizing Proteins in Anhydrous Ionic Liquids through Formation of Protein-Polymer Surfactant Nanoconstructs
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Nonaqueous biocatalysis is rapidly becoming a desirable tool for chemical and fuel synthesis in both the laboratory and industry. Similarly, ionic liquids are increasingly popular anhydrous reaction media for a number of industrial processes. Consequently, the use of enzymes in ionic liquids as efficient, environment-friendly, commercial biocatalysts is highly attractive. However, issues surrounding the poor solubility and low stability of enzymes in truly anhydrous media remain a significant challenge. Here, we demonstrate for the first time that engineering the surface of a protein to yield protein-polymer surfactant nanoconstructs allows for dissolution of dry protein into dry ionic liquids. Using myoglobin as a model protein, we show that this method can deliver protein molecules with near native structure into both hydrophilic and hydrophobic anhydrous ionic liquids. Remarkably, using temperature-dependent synchrotron radiation circular dichroism spectroscopy to measure half-denaturation temperatures, our results show that protein stability increases by 55 °C in the ionic liquid as compared to aqueous solution, pushing the solution thermal denaturation beyond the boiling point of water. Therefore, the work presented herein could provide a platform for the realization of biocatalysis at high temperatures or in anhydrous solvent systems.
- Brogan, Alex P. S.,Hallett, Jason P.
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p. 4494 - 4501
(2016/05/09)
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- Ionic-liquid-mediated active-site control of MoS2 for the electrocatalytic hydrogen evolution reaction
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The layered crystal MoS2 has been proposed as an alternative to noble metals as the electrocatalyst for the hydrogen evolution reaction (HER). However, the activity of this catalyst is limited by the number of available edge sites. It was previously shown that, by using an imidazolium ionic liquid as synthesis medium, nanometre-size crystal layers of MoS2 can be prepared which exhibit a very high number of active edge sites as well as a de-layered morphology, both of which contribute to HER electrocatalytic activity. Herein, it is examined how to control these features synthetically by using a range of ionic liquids as synthesis media. Non-coordinating ILs with a planar heterocyclic cation produced MoS2 with the de-layered morphology, which was subsequently shown to be highly advantageous for HER electrocatalytic activity. The results furthermore suggest that the crystallinity, and in turn the catalytic activity, of the MoS2 layers can be improved by employing an IL with specific solvation properties. These results provide the basis for a synthetic strategy for increasing the HER electrocatalytic activity of MoS2 by tuning its crystal properties, and thus improving its potential for use in hydrogen production technologies. Copyright
- Lau, Vincent Wing-Hei,Masters, Anthony F.,Bond, Alan M.,Maschmeyer, Thomas
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experimental part
p. 8230 - 8239
(2012/08/29)
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- A convenient synthesis of triflate anion ionic liquids and their properties
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A solvent- and halogen-free synthesis of high purity triflate ionic liquids via direct alkylation of organic bases (amines, phosphines or heterocyclic compounds) with methyl and ethyl trifluoromethanesulfonate (methyl and ethyl triflate) has been developed. Cheap and non-toxic dimethyl and diethyl carbonate serve as source for the methyl and ethyl groups in the preparation of methyl and ethyl triflate by this invented process. The properties of ionic liquids containing the triflate anion are determined and discussed.
- Ignat'ev, Nikolai V.,Barthen, Peter,Kucheryna, Andryi,Willner, Helge,Sartori, Peter
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experimental part
p. 5319 - 5338
(2012/08/28)
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- One-pot and solventless synthesis of ionic liquids under ultrasonic irradiation
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A novel method is described for the one-pot synthesis of various ionic liquids in a competitive time. By using ultrasonic irradiation, different families of nitrogen-bearing ionic liquids can be obtained in a solvent-free or in aqueous medium, which gives a greener touch to the overall process. Georg Thieme Verlag Stuttgart.
- Estager, Julien,Lévêque, Jean-Marc,Cravotto, Giancarlo,Boffa, Luisa,Bonrath, Werner,Draye, Micheline
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p. 2065 - 2068
(2008/02/10)
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- METHOD FOR PRODUCING ONIUM SALTS COMPRISING ALKYL ANIONS OR ARYL SULFONATE ANIONS OR ALKYL ANIONS OR ARYL CARBOXYLATE ANIONS HAVING A LOW HALIDE CONTENT
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The invention relates to a method for producing onium salts comprising alkyl anions or aryl sulfonate anions or alkyl carboxylate anions or acryl carboxylate anions by reacting an onium halide with an alkyl silyl ester or trialkyl silyl ester of an alkyl sulfonic acid or aryl sulfonic acid or an alkyl carboxylic acid or aryl carboxylic acid or the anhydrides thereof.
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Page/Page column 37
(2008/06/13)
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- A PURIFICATION METHOD OF IONIC LIQUIDS TO OBTAIN THEIR HIGH PURITY
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Disclosed is an ionic liquid purification method for preparing high purity ionic liquids which can be used as solvents for organic, inorganic and biochemical reactions or as electrolytic solutions of storage batteries, secondary batteries, or fuel batteries, by removing organic halide salts, organic salts, halide residues, acid residues, excess alkali metals and so on, from unpurified ionic liquids using liquid/liquid continuous extraction.
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