- Water-based synthesis of hydrophobic ionic liquids for high-energy electrochemical devices
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In this work is described an innovative synthesis route for hydrophobic ionic liquids (ILs) composed of N-methyl-N-Alkylpyrrolidinium (or piperidinium) or imidazolium or tetralkylammonium cations and (perfluoroalkylsulfonyl)imide, ((CnF2n+
- Montanino, Maria,Alessandrini, Fabrizio,Passerini, Stefano,Appetecchi, Giovanni Battista
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- Fluorescence studies of protein thermostability in ionic liquids
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Using the single tryptophan residue in the sweet protein monellin as a spectroscopic handle, we show the extreme thermodynamic stabilization offered by an ionic liquid; Tun ~ 105°C in [C4mpy][Tf 2N] compared to 40°C in bulk water.
- Baker, Sheila N.,Mark McCleskey,Pandey, Siddharth,Baker, Gary A.
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- Melting behavior and ionic conductivity in hydrophobic ionic liquids
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Four room-temperature ionic liquids (RTILs) based on the N-butyl-N-methyl pyrrolidinium (Pyr14 +) and N-methyl-N-propyl pyrrolidinium cations (Pyr13 +) and bis(trifluoromethanesulfonyl)imide (TFSI-) and bis(fluorosulfonyl) imide (FSI-) anions were intensively investigated during their melting. The diffusion coefficients of 1H and 19F were determined using pulsed field gradient (PFG) NMR to study the dynamics of the cations, anions, and ion pairs. The AC conductivities were measured to detect only the motion of the charged particles. The melting points of these ionic liquids were measured by DSC and verified by the temperature-dependent full width at half-maximum (FWHM) of the 1H and 19F NMR peaks. The diffusion and conductivity data at low temperatures gave information about the dynamics at the melting point and allowed specifying the way of melting. In addition, the diffusion coefficients of 1H (DH) and 19F (DF) and conductivity were correlated using the Nernst-Einstein equation with respect to the existence of ion pairs. Our results show that in dependence on the cation different melting behaviors were identified. In the Pyr14based ILs, ion pairs exist, which collapse above the melting point of the sample. This is in contrast to the Pyr 13-based ILs where the present ion pairs in the crystal dissociate during the melting. Furthermore, the anions do not influence the melting behavior of the investigated Pyr14 systems but affect the Pyr 13 ILs. This becomes apparent in species with a higher mobility during the breakup of the crystalline IL.
- Kunze, Miriam,Montanino, Maria,Appetecchi, Giovanni B.,Jeong, Sangsik,Schoenhoff, Monika,Winter, Martin,Passerini, Stefano
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- Hybrid ionogel electrolytes for high temperature lithium batteries
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Hybrid ionogels fabricated using 1 M LiTFSI in N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPTFSI) crosslinked with ladder-like structured poly(methacryloxypropyl)silsesquioxane (LPMASQ) were investigated as high temperature ionogel electrolytes for lithium ion batteries. In addition to the exceedingly low crosslinker concentration (~2 wt%) required to completely solidify the ionic liquids, which provided high ionic conductivities comparable to the liquid state ionic liquid, these hybrid ionogels exhibited superior thermal stabilities (>400°C). Rigorous lithium ion battery cells fabricated using these hybrid ionogels revealed excellent cell performance at various C-rates at a variety of temperatures, comparable with those of neat liquid electrolytes. Moreover, these hybrid ionogels exhibited excellent cycling performance during 50 cycles at 90°C, sustaining over 98% coulombic efficiency. Highly advantageous properties of these hybrid ionogels, such as high ionic conductivity in the gel state, thermal stability, excellent C-rate performance, cyclability and non-flammability, offer opportunities for applications as high temperature electrolytes.
- Lee, Jin Hong,Lee, Albert S.,Lee, Jong-Chan,Hong, Soon Man,Hwang, Seung Sang,Koo, Chong Min
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- Esterification in ionic liquids: The influence of solvent basicity
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(Chemical Equation Presented) The second-order rate constant (k 2) for the esterification of methoxyacetic acid with benzyl alcohol is reported in a range of ionic and molecular solvents. The solvent effects on esterification rate are examined by using a linear solvation energy relationship based on the Kamlet-Taft solvent scales (α, β, and π*). It is shown that the hydrogen bond basicity of the solvent is the dominant parameter in determining the esterification rate and that the best rates are achieved in low basicity solvents.
- Wells, Thomas P.,Hallett, Jason P.,Williams, Charlotte K.,Welton, Tom
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- Heterocyclic bismuth(III) compounds with transannular N→Bi interactions as catalysts for the oxidation of thiophenol to diphenyldisulfide
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The reactions between the diorganobismuth(iii) bromides [RCH2N(CH2C6H4)2]BiBr [R = C6H5 (1), C6H5CH2 (2)] and appropriate silver salts resulted in new diorganobismuth(iii) compounds of the general formula [RCH2N(CH2C6H4)2]BiX [R = C6H5, X = ONO2 (3), OSO2CF3 (4), OSO2C6H4 (CHCH2)-4 (5); R = C6H5CH2, X = ONO2 (6)], based on a butterfly-like tetrahydro-dibenzo[c,f][1,5]azabismocine heterocyclic framework. The new species were structurally characterized in solution by 1H, 13C{H} and 19F{H} NMR and in the solid state by IR spectroscopy and single-crystal X-ray diffraction. The nitrogen atom is intramolecularly coordinated to bismuth, thus resulting in hypercoordinated species of type 12-Bi-5 (3 and 6) and 10-Bi-4 (4 and 5). In addition, compound 4 shows bismuth?π arene and compounds 3 and 6 bismuth?oxygen intermolecular interactions, thus leading to dimers in the solid state. These compounds were investigated as catalysts for the oxidation of thiophenol to diphenyl disulfide by using air as an oxidizing agent, both in cyclohexane and in an ionic liquid (1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide), at temperatures below 100 °C, affording high reaction rates (TON 34.8, with 100% conversion after 5 h) and a total selectivity to the targeted product.
- Toma, Ana M.,Ra?, Ciprian I.,Pavel, Octavian D.,Hardacre, Christopher,Rüffer, Tobias,Lang, Heinrich,Mehring, Michael,Silvestru, Anca,Parvulescu, Vasile I.
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- Effects of acetonitrile on electrodeposition of Ni from a hydrophobic ionic liquid
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The effects of addition of acetonitrile (ACN) on electrodeposition of nickel were investigated in a hydrophobic room-temperature ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing Ni(TFSA)2. Addition of ACN resulted in the change of the color of the ionic liquid. The UV-vis and FT-IR spectra of the electrolyte showed the coordination environment of Ni(II) changed gradually from [Ni(TFSA)3]- to [Ni(ACN)6]2+ with an increase in the concentration of ACN. The diffusion coefficient of Ni(II) in BMPTFSA was increased and the reduction potential of Ni(II) shifted to the more positive side in the presence of ACN. The nucleation/growth process of Ni was not affected by the change in the coordination environment of Ni(II) from the chronoamperometric results although the more nuclei formed on the electrode surface. SEM showed smoother deposit was obtained in Ni(TFSA) 2/BMPTFSA with ACN.
- Zhu, Yan-Li,Katayama, Yasushi,Miura, Takashi
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- Polyethylene glycol-functionalized siloxane hybrid gel polymer electrolytes for lithium ion batteries
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The compatibility of diacrylate terminated polyethylene glycol-block-polydimethylsiloxane-blockpolyethylene glycol was examined with an ionic liquid solution, 1 M LiTFSI in N-butyl-Nmethylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and through mild UV-curing, hybrid gel polymer electrolytes were fabricated for lithium ion battery application. Obtained hybrid gel polymer electrolytes exhibited good ionic conductivity, electrochemical stability, thermal stability, and mechanical pliancy and the polyethylene glycol domains functioned to increase the ionic dissociation to improve ion conduction compared with gel polymer electrolytes fabricated with a conventional organic crosslinker. Lithium ion battery cell tests with these hybrid gel polymer electrolytes revealed that these hybrid gel polymer electrolytes hold promise as next generation electrolytes.
- Lee, Albert S.,Lee, Jin Hong,Lee, Jong-Chan,Hong, Soon Man,Hwang, Seung Sang,Koo, Chong Min
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- Cyclic quaternary ammonium ionic liquids with perfluoroalkyltrifluoroborates: Synthesis, characterization, and properties
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New cyclic quaternary ammonium salts, composed of N-alkyl(alkyl ether)-N-methylpyrrolidinium, -oxazolidinium, -piperidinium, or -morpholinium cations (alkyl = nC4H9, alkyl ether = CH 3,OCH2, CH3,OCH2CH2) and a perfluoroalkyltrifluoroborate anion ([RFBF3] -, RF = CF3, C2F5, nC3,F7, nC4F9), were synthesized and characterized. Most of these salts are liquids at room temperature. The key properties of these salts - phase transitions, thermal stability, density, viscosity, conductivity, and electrochemical windowswere measured and compared to those of their corresponding [BF4] and [(CF3SO 2)2N]- salts. The structural effect on all the above properties was intensively studied in terms of the identity of the cation and anion, variation of the side chain in the cation (i.e., alkyl versus alkyl ether), and change in the length of the pertluoroalkyl group (RF) in the [RFBF3,]- ion. The reduction of Li + ions and reoxidation of Li metal took place in pure N-butyl-N-methyl pyrrolidinium pentafluoroethyltrifluoroborate as the supporting electrolyte. Such comprehensive studies enhance the knowledge necessary to design and optimize ionic liquids for many applications, including electrolytes. Some of these new salts show desirable properties, including low melting points, high thermal stabilities, low viscosities, high conductivities, and wide electrochemical windows, and may thus be potential candidates for use as electrolytes in high-energy storage devices. In addition, many salts are ionic plastic crystals.
- Zhou, Zhi-Bin,Matsumoto, Hajime,Tatsumi, Kuniaki
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- Pyrrolidinium imides: A new family of molten salts and conductive plastic crystal phases
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A new family of molten salts is reported, based on the N-alkyl, N-alkyl pyrrolidinium cation and the bis-(trifluoromethane sulfonyl)imide anion. Some of the members of the family are molten at room temperature, while the smaller and more symmetrical members have melting points around 100 °C. Of the room-temperature molten salt examples, the methyl butyl derivative exhibits the highest conductivity; at 2 × 10-3 S/cm this is the highest molten salt conductivity observed to date at room temperature among the ammonium salts. This highly conductive behavior is rationalized in terms of the role of cation planarity. The salts also exhibit multiple crystalline phase behavior below their melting points and exhibit significant conductivity in at least their higher temperature crystal phase. For example, the methyl propyl derivative (mp = 12 °C) shows ion conductivity of 1 × 10-6 S/cm at 0 °C in its higher temperature crystalline phase.
- MacFarlane,Meakin,Sun,Amini,Forsyth
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- Ag(I)/Ag electrode reaction in amide-type room-temperature ionic liquids
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Ag(I)/Ag electrode reaction was investigated in some amide-type room-temperature ionic liquids composed of different cations. The morphology of silver deposits and the electrochemical behavior were not sensitive to the difference in the cations of ionic liquids. On the other hand, it was suggested that the adsorption of bis(trifluoromethylsulfonyl)amide (TFSA-) is more important for electrodeposition of silver in both ionic liquids and aqueous solutions. The diffusion coefficients of silver cation in the ionic liquids indicated the silver cation is surrounded by TFSA- to form a bulky species. The rate of crystal growth of silver particles in the ionic liquids by electrochemical Ostwald ripening was much slower than that in a nitrate aqueous solution, suggesting the charge transfer in the ionic liquids is slower than that in the aqueous solution.
- Serizawa, Nobuyuki,Katayama, Yasushi,Miura, Takashi
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- Recombination of lophyl radicals in pyrrolidinium-based ionic liquids
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The recombination of photolytically generated lophyl radicals has been investigated by UV/Vis spectroscopy in 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imides (NTf2) in comparison with 1-butyl-3-methylimidazolium NTf2, dimethyl sulfoxide, and triacetin. The 1-alkyl-1-methylpyrrolidinium-based ionic liquids contain an alkyl substituent varying between butyl and decyl groups. Optically pure ionic liquids are used in these studies. Temperature-dependent investigation of lophyl radical recombination shows an increase in the radical recombination rate with increasing temperature in each solvent, which is caused by decreasing viscosity with increasing temperature. Furthermore, the viscosity of the 1-alkyl-1-methylpyrrolidinium NTf2 increases nearly linearly within the row of these ionic liquids. In contrast, the recombination of the photolytically generated lophyl radicals is significantly faster in the ionic liquids than in the traditional organic solvents under investigation. Moreover, the recombination rate increases with the length of the alkyl chain bound at the cation of the ionic liquid at a given temperature. This may be caused by an increase in the extent of lophyl radical recombination within the solvent cage. Solvent cage effects dominate in the case of lophyl radical recombination in ionic liquids bearing a long alkyl chain or if the temperature is near the melting temperature of the ionic liquid. The positive value of the activation entropy supports this hypothesis. The results obtained are important for discussion of bimolecular radical reactions in ionic liquids. Rate increases: Long alkyl chains bound at the cation of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids change the steric requirements on the transition state of the bimolecular lophyl radical recombination reaction (see picture). Recombination of the photolytically generated radicals is faster in the ionic liquids than in traditional organic solvents. Copyright
- Berdzinski, Stefan,Horst, Joachim,Strassburg, Petra,Strehmel, Veronika
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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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- Electrodeposition of palladium from palladium(II) acetylacetonate in an amide-type ionic liquid
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The electrodeposition of palladium from palladium(II) acetylacetonate (Pd(acac)2) was investigated in an ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide at room temperature. Potentiostatic cathodic reduction was conducted using a glassy carbon electrode at - 2.0 V vs. Ag/Ag(I). Metallic palladium was deposited on the electrode and palladium nanoparticles were observed with dispersed state in the ionic liquid. The mean particle size of the obtained palladium nanoparticles was 2.8 ± 0.6 nm.
- Yoshii, Kazuki,Oshino, Yosuke,Tachikawa, Naoki,Toshima, Kazunobu,Katayama, Yasushi
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- Physical-Chemical Characterization of Binary Mixtures of 1-Butyl-1-methylpyrrolidinium Bis{(trifluoromethyl)sulfonyl}imide and Aliphatic Nitrile Solvents as Potential Electrolytes for Electrochemical Energy Storage Applications
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In the scope of improving the energy and power densities of electrochemical double layer capacitors (EDLCs), the development of high performance electrolytes with enhanced operative voltages is imperative. The formulation of mixtures containing ionic liquids with organic molecular solvents is an important strategy in the pursuit of developing highly electrochemically stable and safe materials while retaining fast transport properties for high power applications. In this work, we report on the physical-chemical investigations into binary mixtures containing the ionic liquid 1-butyl-1-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl}imide with one mononitrile solvent, butyronitrile, and two dinitrile solvents, glutaronitrile and adiponitrile, as potential electrolytes for EDLCs. The thermal, volumetric, and transport properties of the binary mixtures are investigated as functions of the electrolyte composition and temperature. Furthermore, the electrolyte composition which exhibits the highest conductivity for each of the binary mixtures was determined, and its electrochemical stability is reported using a glassy carbon macrodisk electrode. (Graph Presented).
- Neale, Alex R.,Schütter, Christoph,Wilde, Patrick,Goodrich, Peter,Hardacre, Christopher,Passerini, Stefano,Balducci, Andrea,Jacquemin, Johan
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- Facile, high-yielding preparation of pyrrolidinium, piperidinium, morpholinium and 2,3-dihydro-1H-isoindolinium salts and ionic liquids from secondary amines
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High yield and purity heterocyclic ionic liquids can be obtained via the microwave irradiation of equimolar amounts of a secondary amine and of an α,ω-dibromoalkane (i.e., 1,4-dibromobutane, 1,5-dibromopentane, bis(2-bromoethyl)ether, or α,α′-dibromo-o-xylene) in water, in the presence of potassium carbonate, followed by anion exchange with lithium bis(trifluoromethanesulfonyl)imide, affording pyrrolidinum, piperidinium and morpholinium ionic liquids, respectively. Using this methodology, a large number of homologous ionic liquids can be prepared from a small number of readily available and relatively cheap starting materials, including a new class of ionic liquids based on the 2,3-dihydro-1H-isoindolinium ring system. Analysis (using SWOT and the GSK greenness assessments) of this synthetic method and comparison with current literature preparations reveals that this new method delivers significant benefits across a range of relevant parameters.
- Ward, Antony J.,Masters, Anthony F.,Maschmeyer, Thomas
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- Electrochemical Preparation of Platinum Nanoparticles from Bis(acetylacetonato)platinum(II) in Some Aprotic Amide-type Ionic Liquids
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Electrode reaction of bis(acetylacetonato)platinum(II), Pt(acac)2, and preparation of platinum (Pt) nanoparticles have been studied in 1-R-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (R = butyl, hexyl and decyl, which are abbreviated as BMPTFSA, HMPTFSA and DMPTFSA, respectively) ionic liquids by means of cyclic voltammetry and rotating disk electrode (RDE) method. Pt(acac)2 was suggested to be reduced to Pt via a two-electron transfer process at a glassy carbon electrode. The diffusion coefficient of Pt(acac)2 at 50 °C was estimated to be 1.3 × 10?7 cm2 s?1 in BMPTFSA, by RDE measurements. It has been demonstrated that Pt nanoparticles were able to be prepared at the glassy carbon RDE by potentiostatic electrolysis at ?1.8 and ?2.5 V in the ionic liquids containing Pt(acac)2. The prepared nanoparticles were characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy and electron diffraction. No pronounced variation in the average particle sizes of Pt was observed with the rotation rates at the RDE, indicating that the average particle size was independent of the rotation rate or current density. Pt nanoparticles of average sizes of 2.1 ± 0.8, 2.8 ± 0.8 and 3.0 ± 0.8 nm were obtained after electrolysis at ?1.8 V with a rotation rate of 1000 rpm in BMPTFSA, HMPTFSA and DMPTFSA, respectively, suggested that the average particle size may depend on the kind of the ionic liquid.
- Sultana, Sharmin,Tachikawa, Naoki,Yoshii, Kazuki,Toshima, Kazunobu,Magagnin, Luca,Katayama, Yasushi
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- Hybrid ionogel electrolytes derived from polyhedral oligomeric silsesquioxane for lithium ion batteries
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Inorganic-organic hybrid ionogels fabricated with 1 M LiTFSI in N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPTFSI) crosslinked with a fully methacryl-substituted Polyhedral Oligomeric Silsesquioxane (T8-MMA-POSS) were investigated as gel polymer electrolytes for lithium ion batteries. The effect of T8-MMA-POSS on physical properties of the ionogels was characterized in terms of dimensional stability, ion transport behaviour, and thermal stability. A mere 5 wt% concentration of the cross-linker was able to produce non-flowing hybrid ionogels, leading to high ionic conductivity with good mechanical properties. The lithium battery cell fabricated with ionogels revealed high specific capacity and excellent cycling performance with high Coulombic efficiency at elevated temperature, demonstrating that hybrid ionogels could be a promising candidate electrolyte for use in lithium ion batteries.
- Lee, Jin Hong,Lee, Albert S.,Lee, Jong-Chan,Hong, Soon Man,Hwang, Seung Sang,Koo, Chong Min
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- Does the cation really matter? the effect of modifying an ionic liquid cation on an SN2 process
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The rate of reaction of a Menschutkin process in a range of ionic liquids with different cations was investigated, with temperature-dependent kinetic data giving access to activation parameters for the process in each solvent. These data, along with molecular dynamics simulations, demonstrate the importance of accessibility of the charged centre on the cation and that the key interactions are of a generalised electrostatic nature. The Royal Society of Chemistry.
- Tanner, Eden E. L.,Yau, Hon Man,Hawker, Rebecca R.,Croft, Anna K.,Harper, Jason B.
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- Ultrafast dynamics of pyrrolidinium cation ionic liquids
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We have investigated the ultrafast molecular dynamics of five pyrrolidinium cation room temperature ionic liquids using femtosecond optical heterodyne-detected Raman-induced Kerr effect spectroscopy. The ionic liquids studied are N -butyl- N -methylpyrrolidinium bis(trifluoromethylsulfonyl)imide P 14 + NTf2-), N -methoxyethyl- N -methylpyrrolidinium bis(trifluoromethylsulfonyl)imide P 1EOE + NTf2-), N -ethoxyethyl- N -methylpyrrolidinium bis(trifluoromethylsulfonyl)imide P 1EOE + NTf2-), N -ethoxyethyl- N -methylpyrrolidinium bromide P 1EOE +, and N -ethoxyethyl- N -methylpyrrolidinium dicyanoamide P 1EOE + DCA-). For comparing dynamics among the five ionic liquids, we categorize the ionic liquids into two groups. One group of liquids comprises the three pyrrolidinium cations P 14 +, P 1EOM +, and P 1EOE + paired with the NTf2- anion. The other group of liquids consists of the P 1EOE + cation paired with each of the three anions NTf2-, Br-, and DCA-. The overdamped relaxation for time scales longer than 2 ps has been fit by a triexponential function for each of the five pyrrolidinium ionic liquids. The fast (~2 ps) and intermediate (~20 ps) relaxation time constants vary little among these five ionic liquids. However, the slow relaxation time constant correlates with the viscosity. Thus, the Kerr spectra in the range from 0 to 750 cm-1 are quite similar for the group of three pyrrolidinium ionic liquids paired with the NTf2- anion. The intermolecular vibrational line shapes between 0 and 150 cm-1 are fit to a multimode Brownian oscillator model; adequate fits required at least three modes to be included in the line shape.
- Shirota, Hideaki,Funston, Alison M.,Wishart, James F.,Castner Jr., Edward W.
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- Newly designed flow reactor as an original method of synthesis of ionic liquids by ion-exchange reactions
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Optimization of chemical reactions is often costly and requires a significant investment in both materials and time. The solution to this type of difficulty may be the use of continuous flow systems. With the use of the newly designed continuous flow system, the method of synthesizing ionic liquids (ILs) by ion exchange was optimized. The flow rate of the substrates and the selection of the packing of the column in which the reactions were carried out (random packing or a chemical compound in the form of a solid, which was the source of the anion exchanged) were also optimized. The purity of the obtained ionic liquids and the progress of the reaction was determined using ion chromatography. Additionally, for the ionic liquids, which were the starting compounds for the ion exchange reaction, the basic physicochemical properties were determined, thus extending the data library available for chemical compounds belonging to the group of ionic liquids.
- Pawlowska-Zygarowicz, Anna
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- Electrolyte and a battery with said electrolyte
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An electrolyte for a lithium-ion battery, and a battery incorporating the electrolyte. The electrolyte includes a lithium salt, a non-aqueous organic solvent which includes a carbonate-based solvent, a flame retardant, a film former, and a stabilizing medium. The flame retardant includes PYR1RPF6 (N-Methyl-N-alkylpyrrolidinium Hexafluorophosphate Salt).
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- Evaluation of ionic liquids as electrolytes for vanadium redox flow batteries
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Non-aqueous redox flow batteries (NARFBs) are promising electrochemical energy storage devices due to their wide electrochemical potential windows, generally >2 V of organic solvents. This study aims to investigate the suitability of ionic liquids (ILs) as electrolytes for NARFBs containing a vanadium metal complex. The electrochemistry of a single-component NARFBs employing vanadium (III) acetylacetonate (V(acac)3) was studied in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C4mim][NTF2], and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, [C4mpyr][NTF2], electrolytes. The electrochemical kinetics of the anodic and cathodic reactions was measured using cyclic voltammetry. The VII/VIII and VIII/VIV couples were quasi-reversible and together yielded a cell potential of 2.2 V in both ILs. Charge/discharge characteristics show that a coulombic efficiency for cycles 1–50 ranged from 88 to 92% using a V(acac)3/[C4mpyr][NTF2] cell.
- Bahadori, L.,Boyd, R.,Nockemann, P.,Shafeeyan, M. S.,Warrington, A.
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- Controlling the reactions of 1-bromogalactose acetate in methanol using ionic liquids as co-solvents
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The reactions of an acetobromogalactose in mixtures of methanol and one of seven different ionic liquids with varying constituent ions were studied. In general, small amounts of ionic liquid in the reaction mixture led to increases in the rate constant compared to methanol, whilst large amounts of ionic liquid led to decreases in the rate constant; this outcome differs significantly from previous reactions proceeding through this mechansim. Temperature dependent kinetic studies indicated that the dominant interaction driving these changes was between the ionic liquid and the transition state of the process. Through considering solvent parameters of ionic liquids, a relationship was found between the changes in the rate constant and both the hydrogen bond accepting ability and polarisability of the solvent, indicating that the interactions affecting reaction outcome are both specific and non-specific in nature; once more, these interactions were different to those observed in previous similar reactions. By changing the amount of ionic liquid in the reaction mixture, additional products not seen in the molecular solvent case were observed, the ratios of which are dependent on the anion of the ionic liquid and the proportion of ionic liquid in the reaction mixture. This demonstrates the importance of considering solvent effects on both the rate and product determining steps and the potential application of such changes is discussed.
- Gilbert, Alyssa,Haines, Ronald S.,Harper, Jason B.
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supporting information
p. 5442 - 5452
(2020/09/09)
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- Binary Mixtures of Aprotic and Protic Ionic Liquids Demonstrate Synergistic Polarity Effect: An Unusual Observation
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In this communication, we demonstrate the solute–solvent and solvent–solvent interactions in the binary mixtures of two aprotic ionic liquids, namely 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-butyl-1-methylpyrrolidinium bis(trifl
- Thawarkar, Sachin,Khupse, Nageshwar D.,Kumar, Anil
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p. 210 - 221
(2020/02/25)
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- Understanding the effects of ionic liquids on a unimolecular substitution process: Correlating solvent parameters with reaction outcome
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A unimolecular substitution process was studied in five different ionic liquids, with systematic variation of either the cation or anion, in order to determine the factors leading to the increase in the rate constant for the process relative to acetonitrile. It was found that both components of the ionic liquid, and the proportion of the salt in the reaction mixture, affect the rate constant. Activation parameters determined for the process suggest that there is a balance between interactions of the components of the ionic liquid with both starting material and transition state. A correlation was found between the rate constant and a combination of Kamlet-Taft solvent parameters; with the polarisability of the solvent being the most significant factor. As this reaction proceeds through both unimolecular and bimolecular pathways, competition experiments determined that the unimolecular pathway for the reaction can be favoured using small amounts of ionic liquid in the reaction mixture, demonstrating the potential to control reaction mechanisms using ionic liquids.
- Gilbert, Alyssa,Haines, Ronald S.,Harper, Jason B.
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supporting information
p. 675 - 682
(2019/01/24)
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- Correlating ionic liquid solvent effects with solvent parameters for a reaction that proceeds through a xanthylium intermediate
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A unimolecular nucleophilic substitution reaction that proceeds through a xanthylium carbocation was studied in seven ionic liquid solvents. It was found that the general trend in the rate constant with changing proportion of ionic liquid in the reaction mixture was different to that seen for other unimolecular processes, with the rate constant increasing as more ionic liquid was added to the reaction mixture. A significant correlation was found between the natural logarithm of the rate constant and a combination of the Kamlet-Taft solvent parameters. This relationship indicated that the principal interaction involved hydrogen bonding between the ionic liquid and some species along the reaction coordinate. Further, this correlation enables prediction of the effects that other ionic liquids will have on this, and other, reactions that proceed through a similar intermediate.
- Gilbert, Alyssa,Bucher, G?tz,Haines, Ronald S.,Harper, Jason B.
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supporting information
p. 9336 - 9342
(2019/11/13)
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- Understanding the behavior of mixtures of protic-aprotic and protic-protic ionic liquids: Conductivity, viscosity, diffusion coefficient and ionicity
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We have investigated the physicochemical properties such as electrical conductivity, viscosity and diffusion coefficient for the binary mixtures of protic ionic liquids with aprotic ionic liquids and of protic with protic ionic liquids at 298.15 K. A significant enhancement in the electrical conductivity is observed for the binary mixtures of ionic liquids, as compared to those of the constituent pure ionic liquids and varied with the composition of the mixtures. The viscosity of binary mixtures of protic with aprotic ionic liquids, 1?butyl?3?methylimidazoliumbis(trifluoromethylsulfonyl)imide [bmIm][NTf2], 1?butyl?1?methylpyrrolidiumbis(trifluoromethylsulfonyl)imide [bmPyrr][NTf2] and 1,3-dimethylimidazolium methyl sulfate, [mmIm][CH3SO4] decreases with an increase in the composition of the [HmIm][CH3COO]. On the contrary, the viscosity for binary mixtures of protic with protic ionic liquid, 1?methylpyrrolidium acetate [HmPyrr][CH3COO] and 4?methylmorpholine acetate [HmMorph][CH3COO] increases upon the addition of 1?methylimidazolium acetate [HmIm][CH3COO]. The self diffusion coefficients were determined for all the binary mixtures of ionic liquids by using Pulsed Gradient Spin Echo (PGSE) NMR method. Self diffusion coefficients of [bmIm][NTf2]-[HmIm][CH3COO], [bmPyrr][NTf2]-[HmIm][CH3COO], [mmIm][CH3SO4]-[HmIm][CH3COO] are enhanced, while those of [HmPyrr][CH3COO]-[HmIm][CH3COO] and [HmMorph][CH3COO]-[HmIm][CH3COO] decreases on addition of [HmIm][CH3COO]. This is converse in the case of viscosity. Furthermore, the above correlations were interpreted with the help of NMR spectroscopy on the basis of interactions of ions in the binary mixtures of ionic liquids. Finally, we have quantified the ionicity through the Nernst–Einstein equation and have confirmed the validity of the Walden rule for the binary mixture of ionic liquids.
- Thawarkar, Sachin,Khupse, Nageshwar D.,Shinde, Dinesh R.,Kumar, Anil
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p. 986 - 994
(2019/02/03)
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- An ionic compound, and an electrolyte solution and a secondary battery comprising an ionic compound
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An electrolyte for a secondary, battery and Si an electrolytic solution for a secondary battery and 1 a 2 secondary battery comprising the same are provided to improve the stability of a secondary battery by using an ionic compound having a structure represented by the following Chemical Formula I, No.No. STR84No.No. wherein X is an ionic compound having a structure represented by Structural Formula (I). No.No. STR84No.No. The compound of formula ( Claim The compound of formula ( Claim (by machine translation)
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Paragraph 0113; 0126; 0129-0130
(2020/04/17)
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- Dissolution of oligo(tetrafluoroethylene) and preparation of poly(tetrafluoroethylene)-based composites by using fluorinated ionic liquids
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Fluorophilic ionic liquids (ILs) showing enhanced compatibility with poly(tetrafluoroethylene) (PTFE) have been newly synthesised. The as-designed ILs contributed both to the dissolution of PTFE oligomers and to the preparation of composites with PTFE with no fear of bleed-out of the ILs.
- Tsurumaki, Akiko,Ohno, Hiroyuki
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supporting information
p. 409 - 412
(2018/02/27)
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- A method for preparing ionic liquid
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The invention provides a preparation method for an ionic liquid. The method comprises the following steps: a, reacting a tertiary amine compound, tertiary imine compound or tertiary phosphorus compound with carbonate so as to obtain an intermediate containing quaternary ammonium cation or quaternary phosphorus cation; and b, reacting the intermediate produced in the step a with an imine compound, or subjecting the intermediate produced in the step a to hydrolysis at first and then to a reaction with the imine compound or an imine salt. The imine type quaternary ammonium or quaternary phosphorus ionic liquid prepared by using the method is especially applicable to a halide-ion-sensitive electrochemical system, e.g., a lithium ion secondary battery and an electrochemical super capacitor. According to the method, raw materials are non-toxic and harmless; reaction conditions are mild; requirements on production equipment are not high; all the conventional reaction vessels applicable to liquid phase reactions can be used in principle; and operations like feeding, mixing, distilling and filtering are simple.
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Paragraph 0070; 0071
(2018/01/11)
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- Thermophysical and Electrochemical Properties of Ethereal Functionalised Cyclic Alkylammonium-based Ionic Liquids as Potential Electrolytes for Electrochemical Applications
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A series of hydrophobic room temperature ionic liquids (ILs) based on ethereal functionalised pyrrolidinium, piperidinium and azepanium cations bearing the bis[(trifluoromethyl)sulfonyl]imide, [TFSI]?, anion were synthesized and characterized. Their physicochemical properties such as density, viscosity and electrolytic conductivity, and thermal properties including phase transition behaviour and decomposition temperature have been measured. All of the ILs showed low melting point, low viscosity and good conductivity and the latter properties have been discussed in terms of the IL fragility, an important electrolyte feature of the transport properties of glass-forming ILs. Furthermore, the studied [TFSI]?-based ILs generally exhibit good electrochemical stabilities and, by coupling electrochemical experiments and DFT calculations, the effect of ether functionalisation at the IL cation on the electrochemical stability of the IL is discussed. Preliminary investigations into the Li-redox chemistry at a Cu working electrode are also reported as a function of ether-functionality within the pyrrolidinium-based IL family. Overall, the results show that these ionic liquids are suitable for electrochemical devices such as battery systems, fuel cells or supercapacitors.
- Neale, Alex R.,Murphy, Sinead,Goodrich, Peter,Hardacre, Christopher,Jacquemin, Johan
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p. 2040 - 2057
(2017/08/10)
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- The impact of ionic liquids on the coordination of anions with solvatochromic copper complexes
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Solvatochromic transition metal (TM)-complexes with weakly associating counter-anions are often used to evaluate traditional neutral solvent and anion coordination ability. However, when employed in ionic liquids (IL) many of the common assumptions made are no longer reliable. This study investigates the coordinating ability of weakly coordinating IL anions in traditional solvents and within IL solvents employing a range of solvatochromic copper complexes. Complexes of the form [Cu(acac)(tmen)][X] (acac = acetylacetonate, tmen = tetramethylethylenediamine) where [X]- = [ClO4]-, Cl-, [NO3]-, [SCN]-, [OTf]-, [NTf2]- and [PF6]- have been synthesised and characterised both experimentally and computationally. ILs based on these anions and imidazolium and pyrrolidinium cations, some of which are functionalised with hydroxyl and nitrile groups, have been examined. IL-anion coordination has been investigated and compared to typical weakly coordinating anions. We have found there is potential for competition at the Cu-centre and cases of anions traditionally assigned as weakly associating that demonstrate a stronger than expected level of coordinating ability within ILs. [Cu(acac)(tmen)][PF6] is shown to contain the least coordinating anion and is established as the most sensitive probe studied here. Using this probe, the donor numbers (DNs) of ILs have been determined. Relative donor ability is further confirmed based on the UV-Vis of a neutral complex, [Cu(sacsac)2] (sacsac = dithioacetylacetone), and DNs evaluated via23Na NMR spectroscopy. We demonstrate that ILs can span a wide donor range, similar in breadth to conventional solvents.
- Kuzmina,Hassan,Patel,Ashworth,Bakis,White,Hunt,Welton
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supporting information
p. 12185 - 12200
(2017/09/25)
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- Rationalising the effects of ionic liquids on a nucleophilic aromatic substitution reaction
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The nucleophilic aromatic substitution reaction between 1-fluoro-2,4-dinitrobenzene and ethanol was examined in a series of ionic liquids across a range of mole fractions. Temperature-dependent kinetic analyses were undertaken to determine the activation parameters for this reaction at the highest mole fraction. As the mole fraction of ionic liquid was increased, the rate constant of the reaction also increased, however the microscopic origin of the rate enhancement was shown to be different between different ionic liquids and also between different solvent compositions. These results indicate a balance between microscopic interactions that result in the observed solvent effects and a qualitative method for analysing such interactions is introduced.
- Hawker, Rebecca R.,Wong, Michaela J.,Haines, Ronald S.,Harper, Jason B.
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p. 6433 - 6440
(2017/08/10)
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- Comprehensive Insights into the Thermal Stability, Biodegradability, and Combustion Chemistry of Pyrrolidinium-Based Ionic Liquids
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The use of ionic liquids (ILs) as advanced electrolyte components in electrochemical energy-storage devices is one of the most appealing and emerging options. However, although ILs are hailed as safer and eco-friendly electrolytes, to overcome the limitations imposed by the highly volatile/combustible carbonate-based electrolytes, full-scale and precise appraisal of their overall safety levels under abuse conditions still needs to be fully addressed. With the aim of providing this level of information on the thermal and chemical stabilities, as well as actual fire hazards, herein, a detailed investigation of the short- and long-term thermal stabilities, biodegradability, and combustion behavior of various pyrrolidinium-based ILs, with different alkyl chain lengths, counteranions, and cations, as well as the effect of doping with lithium salts, is described.
- Eshetu, Gebrekidan Gebresilassie,Jeong, Sangsik,Pandard, Pascal,Lecocq, Amandine,Marlair, Guy,Passerini, Stefano
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p. 3146 - 3159
(2017/08/18)
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- A Comparison among Viscosity, Density, Conductivity, and Electrochemical Windows of N-n-Butyl-N-methylpyrrolidinium and Triethyl-n-pentylphosphonium Bis(fluorosulfonyl imide) Ionic Liquids and Their Analogues Containing Bis(trifluoromethylsulfonyl) Imide Anion
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Ionic liquid consists of an organic cation and generally an inorganic anion. The properties of liquids can be modulated by changing the anion or the cation or both. Two ionic liquids derived from the anion [FSI] were synthesized and characterized: (N-n-butyl-N-methylpyrrolidinium bis(fluorosulfonyl imide), [BMPYR][FSI]) and triethyl-n-pentylphosphonium bis(fluorosulfonyl)imide), [P2225][FSI]). We also report the comparison with [TFSI] based ionic liquids, namely: (N-n-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide), [BMPYR][TFSI]), (N-n-butyl-N-methylpiperidinium bis(trifluoromethylsulfonyl)imide), [BMP][TFSI]), triethyl-n-pentylphosphonium bis(trifluoromethylsulfonyl)imide), [P2225][TFSI]) and (triethyl(2-methoxyethyl) phosphonium bis(trifluoromethylsulfonyl imide), [P222201][TFSI]. Thermophysical properties, such as viscosity (298.15-373.15 K), density (298.15-373.15 K), conductivity (298.15-361.15 K), electrochemical (cutoff density current within 150 μA·cm-2), and thermal stability (303.15-973.15 K) were experimentally determined. The results showed that [FSI] derivatives exhibit better transport properties and lower thermal and electrochemical stability when compared with their [TFSI] counterparts.
- Sánchez-Ramírez, Nédher,Assresahegn, Birhanu Desalegn,Bélanger, Daniel,Torresi, Roberto M.
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p. 3437 - 3444
(2017/10/19)
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- Effect of cation structure on the oxygen solubility and diffusivity in a range of bis{(trifluoromethyl)sulfonyl}imide anion based ionic liquids for lithium-air battery electrolytes
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This paper reports on the solubility and diffusivity of dissolved oxygen in a series of ionic liquids (ILs) based on the bis{(trifluoromethyl)sulfonyl}imide anion with a range of related alkyl and ether functionalised cyclic alkylammonium cations. Cyclic voltammetry has been used to observe the reduction of oxygen in ILs at a microdisk electrode and chronoamperometric measurements have then been applied to simultaneously determine both the concentration and the diffusion coefficient of oxygen in different ILs. The viscosity of the ILs and the calculated molar volume and free volume are also reported. It is found that, within this class of ILs, the oxygen diffusivity generally increases with decreasing viscosity of the neat IL. An inverse relationship between oxygen solubility and IL free volume is reported for the two IL families implying that oxygen is not simply occupying the available empty space. In addition, it is reported that the introduction of an ether-group into the IL cation structure promotes the diffusivity of dissolved oxygen but reduces the solubility of the gas.
- Neale, Alex R.,Li, Peilin,Jacquemin, Johan,Goodrich, Peter,Ball, Sarah C.,Compton, Richard G.,Hardacre, Christopher
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p. 11251 - 11262
(2016/05/24)
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- Synthesis of traditional and ionic polymethacrylates by anion catalyzed group transfer polymerization
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The hydrophobic ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide was successfully used as solvent in group transfer polymerization of traditional methacrylates (methyl methacrylate, n-butyl methacrylate, and benzyl methacrylate) and of ionic liquid methacrylates (ILMAs). This demonstrates that this ionic liquid makes reaction conditions, which do not require the use of ultra-dried solvents. The ILMAs were N-[2-(methacryloyloxy)ethyl]-N,N-dimethyl-N-alkylammonium bis(trifluoromethylsulfonyl)imides bearing methyl, ethyl, propyl, butyl, or hexyl substituents. Increasing size of the alkyl substituent at the cation results in decreasing glass transition temperature in case of both ionic liquid methacrylates and polymers derived of them. Furthermore, the glass transition temperature is significantly higher for these polymers compared with the ionic liquid methacrylates, and the effect of glass transition temperature reduction with increasing size of the alkyl substituent is stronger for the polymers. A mechanism was proposed explaining the catalytic function of the ionic liquid used as solvent for polymerization.
- Strehmel, Veronika,Senkowski, Volker
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p. 2849 - 2859
(2016/01/12)
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- Method of using ionic liquids to improve the lubrication of chains, steel belts, wheel bearings, roller bearings, and electric motors
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A method in which an improved lubricating composition containing ionic liquids is used to enable operation of chains, steel belts, wheel bearings, roller bearings, sliding bearings and electric motors for at least 48 hours by reducing the evaporation loss and the lackification tendency of the lubricant due to the lubricant being protected against thermal and oxidative attack.
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- Steric, hydrogen-bonding and structural heterogeneity effects on the nucleophilic substitution of N-(p-fluorophenyldiphenylmethyl)-4-picolinium chloride in ionic liquids
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The nucleophilic substitution of N-(p-fluorophenyldiphenylmethyl)-4- picolinium chloride was investigated using water and a range of alcoholic nucleophiles in ionic liquid solvents. The reactivity patterns across the nucleophiles examined could be attributed to steric factors, which mediated the relative nucleophilicities. Reducing the hydrogen-bond acidity of the ionic liquid cation was found to generally increase the rate of reaction, however, the magnitude of this rate effect could be influenced by the steric bulk of the nucleophile and the structural heterogeneity of the ionic liquid. Preferential solvation phenomena in binary mixtures of ionic liquids were examined and suggest that the mechanism behind the hydrogen-bond solvation phenomenon arises from direct cation-mediated, rather than indirect anion-mediated, effects. The Royal Society of Chemistry 2013.
- Weber, Cameron C.,Masters, Anthony F.,Maschmeyer, Thomas
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p. 2534 - 2542
(2013/06/05)
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- Probing the importance of ionic liquid structure: A general ionic liquid effect on an SNAr process
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The effect of a range of ionic liquids, with systematic variations in the cation and anion, on the rate constant of an aromatic substitution process was investigated. Temperature-dependent kinetic data allowed calculation of activation parameters for the process in each solvent. These data demonstrate a generalised ionic liquid effect, with an increase in rate constant observed in each ionic solvent, though the microscopic origins of the rate constant enhancement differ with the nature of the ionic liquid.
- Tanner, Eden E. L.,Hawker, Rebecca R.,Yau, Hon Man,Croft, Anna K.,Harper, Jason B.
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p. 7516 - 7521
(2013/11/06)
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- A silver and water free metathesis reaction: A route to ionic liquids
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A versatile, cheaper, silver and water-free metathesis reaction was developed for imidazolium, phosphonium and pyrrolidinium based ionic liquids (ILs) associated with different anions such as dicyanamide, thiocyanate, tetrafluoroborate and bis(trifluoromethylsulfonyl)imide. This route, using the melt of amine chloride as a solvent and reagent, favours the ion exchange reaction using anion salts of Na or Li, yielding ionic liquids in high purity (≥99.5%) and high yields (≥90%). This route is particularly well adapted for water miscible ILs preparation.
- Srour, Hassan,Rouault, Helene,Santini, Catherine C.,Chauvin, Yves
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supporting information
p. 1341 - 1347
(2013/06/05)
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- Standard pKa scales of carbon-centered indicator acids in ionic liquids: Effect of media and structural implication
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Energetics of bond dissociation, especially the R-H bond heterolysis free energy (pKa), has played a central role in promoting chemistry to become a rational science. Despite the oceans of acidity studies in the literature, the current knowledge is limited to that in the classical molecular solvents and is unable to be extended to anticipate the acidity changes in ionic media. As the latter is now very popular for replacing volatile organic solvents, it becomes highly desirable to know how the driving force of bond cleavage is varied as the medium composition is switched from neutral molecules to the charged ions. Here we describe a general approach to measure absolute pKa's in pure ionic liquid (IL). The standard conditions warranting accurate measurement were outlined. The pKa's of the selected 18 C-H type indicator acids in four ILs were determined and a convenient indicator platform was constructed for easy expansion of acidity scales. These absolute pKa's make possible, for the first time, direct comparisons of bond energies in IL with those in molecular solvent and in the gas phase and should be able to serve as the standard parameters for calibrating computational methods suitable for the studies in ionic media. The effect of cation and anion in IL in relation to structure was analyzed.
- Deng, Hui,Li, Xin,Chu, Yuan,He, Jiaqi,Cheng, Jin-Pei
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p. 7291 - 7298
(2012/11/07)
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- H2O2/NaHCO3-mediated enantioselective epoxidation of olefins in NTf2-based ionic liquids and under ultrasound
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The bicarbonate-activated peroxide (BAP) system has been shown to constitute an excellent and versatile combination for the epoxidation of olefins. Herein, we demonstrate that the benign H2O 2/NaHCO3 oxidative combination can be used for the enantioselective epoxidation of olefins using a chiral manganese porphyrin as a catalyst. This unprecedented result was made possible by the use of an ionic liquid with ultrasound, which leads to the activation of Mn-porphyrin catalysis.
- Chatel, Gregory,Goux-Henry, Catherine,Mirabaud, Anais,Rossi, Thomas,Kardos, Nathalie,Andrioletti, Bruno,Draye, Micheline
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experimental part
p. 127 - 132
(2012/08/13)
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- Electrochemical and spectroscopic study of Ce(III) coordination in the 1-butyl-3-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid containing chloride ion
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Cyclic staircase voltammetry, controlled potential coulometry, and electronic absorption spectroscopy were used to probe the coordination and accessible oxidation states of Ce3+ dissolved in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BuMePyroTf 2N) before and after the addition of chloride ion as BuMePyroCl. Controlled potential coulometry indicated that the oxidation of Ce metal in this ionic liquid produces only Ce3+. Spectroscopic examination of the resulting solutions indicated that Ce3+ was weakly solvated by Tf2N- ions as [Ce(Tf2N)x] (x-3)-, x ≥ 3. This species can be reduced at negative potentials, probably to a related Ce2+ species, but the latter is unstable and quickly disproportionates to Ce3+ and Ce0; the latter appears to react with the ionic liquid. The addition of Cl- to solutions of [Ce(Tf2N)x](x-3)- causes the precipitation of CeCl3(s), providing a convenient route to the nondestructive recovery of Ce3+ from the ionic liquid. However, as the Cl- concentration is further increased, the CeCl3(s) redissolves as the octahedral complex, [CeCl6]3-, and the voltammetric and spectroscopic signature for [Ce(Tf2N) x](x-3)- disappears. Absorption spectroscopy indicated that the bulk controlled potential oxidation of solutions containing [CeCl 6]3- produces [CeCl6]2-. Although stable on the time scale of voltammetry, this species slowly reacts with the ionic liquid and is converted back to [CeCl6]3-.
- Chou, Li-Hsien,Cleland, Walter E.,Hussey, Charles L.
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p. 11450 - 11457,8
(2020/10/15)
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- Physical and electrochemical properties of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide
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The ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate 1-butyl-3-methylimidazolium trifluoromethanesulfonate and 1-butyl-1- methylpyrrolidinium bis(trifluoromethylsulfonyl)imide were prepared and several of their properties including viscosities, thermal stability, surface tension, refractive index, pH and density were investigated as a function of temperature. The coefficients of thermal expansion of the ionic liquids were also calculated from the experimental values of the density at various temperatures. The electrochemical stability of the ionic liquids, as electrolytes for voltammetric aspects, was studied at glassy carbon electrode. The results revealed a wide voltage range of the electrochemical window, which allowed studies on compounds such as furaldehydes.
- Shamsipur, Mojtaba,Beigi, Ali Akbar Miran,Teymouri, Mohammad,Pourmortazavi, Sayed Mahdi,Irandoust, Mohsen
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scheme or table
p. 43 - 50
(2011/12/01)
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- A recyclable triethylammonium ion-tagged diphenylphosphine palladium complex for the Suzuki-Miyaura reaction in ionic liquids
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Suzuki-Miyaura reactions of aryl bromides and arylboronic acids proceed in good to excellent yields in a pyrrolidinium ionic liquid by using a preformed air stable and easily handled triethylammonium-tagged diphenylphosphine palladium(ii) complex (2). The reaction requires short reaction times and mild temperature conditions and does not show any tendency towards the formation of palladium black. After extraction of the product, the catalyst containing ionic liquid phase is easily recycled for 6 times, with no significant loss of catalytic activity.
- Lombardo, Marco,Chiarucci, Michel,Trombini, Claudio
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supporting information; experimental part
p. 574 - 579
(2010/04/23)
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- A rationalization of the solvent effect on the Diels-Alder reaction in ionic liquids using multiparameter linear solvation energy relationships
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The Diels-Alder reaction between cyclopentadiene and three dienophiles (acrolein, methyl acrylate and acrylonitrile) having different hydrogen bond acceptor abilities has been carried out in several ionic liquids and molecular solvents in order to obtain information about the factors affecting reactivity and selectivity. The solvent effects on these reactions are examined using multiparameter linear solvation energy relationships. The collected data provide evidence that the solvent effects are a function of both the solvent and the solute. For a solvent effect to be seen, the solute must have a complimentary character; selectivities and rates are determined by the solvent hydrogen bond donation ability (α) in the reactions of acrolein and methyl acrylate, but not of acrylonitrile. The Royal Society of Chemistry 2008.
- Bini, Riccardo,Chiappe, Cinzia,Mestre, Veronica Llopsis,Pomelli, Christian Silvio,Welton, Thomas
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supporting information; experimental part
p. 2522 - 2529
(2009/02/02)
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- Europium-based ionic liquids as luminescent soft materials
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Low melting, highly luminescent: [C3mim] [Eu(Tf 2N)4] (1), [C4mim][Eu(Tf2N) 4], and [C4mpyr]2[Eu(Tf2N) 5] are the first lanthanide ionic liquids that do not need stabilization of the liquid state by neutral coligands. They show excellent photophysical properties, such as long lifetimes of luminescence at large EuIII concentration, small line width, and high color purity (see emission spectrum of 1 and photograph of a sample under UV light).
- Tang, Sifu,Babai, Arash,Mudring, Anja-Verena
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supporting information; experimental part
p. 7631 - 7634
(2009/04/11)
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- ANTISTATIC AGENT AND PLASTIC COMPOSITION COMPRISING THE SAME
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Disclosed is a salt formed of a pyrrolidinium cation or pyrrolidinium derivative cation and a perfluoroalkylsulfone-based anion. An antistatic agent comprising the above salt and a plastic composition comprising the above antistatic agent are also disclosed.
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Page/Page column 8-9
(2008/06/13)
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- Reversible electro-optic device employing aprotic molten salts and method
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A reversible electro-optic device includes a medium of variable transmittance to light. The medium includes a soluble redox couple of a first soluble metal containing species and a second soluble metal containing species. The metal of the soluble redox couple is capable of being electrodeposited. The medium also includes one or more anodic compound(s) capable of being oxidized. An alternate medium includes a soluble metal-containing species and a soluble anodic compound, where the soluble metal-containing species includes metal capable of being electrodeposited, and the anodic compound is capable of being oxidized to a soluble oxidized anodic compound. Another electro-optic device includes a medium of variable reflection to light.
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Page/Page column 9
(2008/06/13)
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