- Induction of lignin solubility for a series of polar ionic liquids by the addition of a small amount of water
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Addition of a small amount of water was found to induce the lignin solubilizing ability in several polar ionic liquids which showed no lignin solubility in the absence of water. Similarly, addition of water was found to enhance lignin solubility in many polar ionic liquids. Though addition of water lowered the proton accepting ability of these ionic liquids, their proton donating ability was found to increase. The lignin dissolution by ionic liquids was newly found to be a function of both the proton accepting ability and proton donating ability of the ionic liquids. Water is a poor solvent for polysaccharides, and water addition has therefore been confirmed to be effective to improve the selective extraction yield of lignin from cedar powder under mild conditions.
- Akiba, Takashi,Tsurumaki, Akiko,Ohno, Hiroyuki
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- Study on enthalpy and molar heat capacity of solution for the ionic liquid [C2mim][OAc] (1-Ethyl-3-methylimidazolium acetate)
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An acetic acid ionic liquid (AcAIL) [C2mim][OAc] (1-ethyl-3-methylimidazolium acetate) was prepared by the neutralization method. Using the solution-reaction isoperibol calorimeter, molar enthalpies of solution, δsolHm, for the ionic liquid [C 2mim][OAc] with different molalities were measured in the temperature range from (288.15 to 308.15 ± 0.01) K with an interval of 5 K. In terms of Archer's method, the standard molar enthalpies of solution, δsolHmθ, for [C2mim] [OAc] were obtained in the temperature range of (288.15 to 308.15 ± 0.01) K. Plotting δsolHmθ against (T - 298.15) K, a good straight line was obtained, with the slope of the line being the standard molar heat capacity of solution, δCp,m θ = 411 J·K-1·mol-1, for [C2mim][OAc], and the specific heat capacity of solution, δCpθ = 2.4 J·g -1·K-1, was also obtained.
- Ma, Xiao-Xue,Li, Long,Wei, Jie,Duan, Wen-Bin,Guan, Wei,Yang, Jia-Zhen
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- A novel and simple procedure to synthesize chitosan-graft-polycaprolactone in an ionic liquid
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An ionic liquid, 1-ethyl-3-methylimidazolium acetate (EMIMAc), was synthesized and employed as a homogeneous and green reaction media to prepare chitosan-graft-polycaprolactone (CS-g-PCL) via ring-opening polymerization, using stannous octoate (Sn(Oct)2) as a catalyst. The structures and compositions of copolymers could be facilely controlled by the reaction conditions and feed ratios. The grafting content of polycaprolactone (PCL) could reach as high as 630%. The chemical structures of the copolymers were systematically characterized by 1H NMR, Fourier transform infrared spectroscopy (FTIR) and wide-Angle X-ray diffraction (WAXD), while thermal properties were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal stability and glass transition temperature (Tg) of the graft copolymers vary regularly with the change of PCL grafting content.
- Wang, Zhaodong,Zheng, Liuchun,Li, Chuncheng,Zhang, Dong,Xiao, Yaonan,Guan, Guohu,Zhu, Wenxiang
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- Theoretical and experimental investigation on dissolution and regeneration of cellulose in ionic liquid
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Density functional theory calculations and atoms in molecules theory were performed to investigate the mechanism of cellulose dissolution and regeneration in 1-ethyl-3-methylimidazolium acetate ([emim]Ac), and (1,4)-dimethoxy-β- D-glucose (Glc) was chosen as the model for cellulose. The theoretical results show that the interaction of [emim]Ac with Glc is stronger than that of Glc with Glc. Further studies indicate that the anion acetate of [emim]Ac forms strong H-bonds with hydroxyl groups of Glc. It is also observed that the H-bonds between [emim]Ac and Glc are weakened or even destroyed by the addition of water. In addition, both the original and regenerated cellulose samples were characterized with FT-IR, XRD, TGA and SEM. The experimental results prove that cellulose can be readily reconstituted from the [emim]Ac-based cellulose solution by the addition of water and the crystalline structure of cellulose is converted to cellulose II from cellulose I in the original cellulose.
- Ding, Zhen-Dong,Chi, Zhen,Gu, Wen-Xiu,Gu, Sheng-Ming,Liu, Jian-Hua,Wang, Hai-Jun
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- Catalytic conversion of cellulose to 5-hydroxymethyl furfural using acidic ionic liquids and co-catalyst
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Efficient catalytic conversion of microcrystalline cellulose (MCC) to 5-hydroxymethyl furfural (HMF), is achieved using acidic ionic liquids (ILs) as the catalysts and metal salts as co-catalysts in the solvent of 1-ethyl-3-methylimidazo-lium acetate ([emim][Ac]). A series of acidic ILs has been synthesized and tested in conversion of MCC to HMF. The effect of reaction conditions, such as reaction time, temperature, catalyst dosage, metal salts, water dosage, Cu2+ concentration and various acidic ILs are investigated in detail. The results show that CuCl2 in 1-(4-sulfonic acid) butyl-3-methylimidazolium methyl sulfate ([C4SO 3Hmim][CH3SO3]), is found to be an efficient catalyst for catalytic conversion of MCC to HMF, and 69.7% yield of HMF is obtained. A mechanism to explain the high activity of CuCl2 in [C4SO3Hmim][CH3SO3] is proposed. To the best of our knowledge, this report first proposes that the Cu2+ and [C4SO3Hmim][CH3SO3] show better catalytic performance in catalytic conversion of MCC to HMF.
- Ding, Zhen-Dong,Shi, Jin-Cai,Xiao, Jing-Jing,Gu, Wen-Xiu,Zheng, Chang-Ge,Wang, Hai-Jun
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- Thermal decomposition of carboxylate ionic liquids: Trends and mechanisms
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The thermal stability of a series of dialkylimidazolium carboxylate ionic liquids has been investigated using a broad range of experimental and computational techniques. Ionic liquids incorporating fluoroalkyl carboxylate anions were found to have profoundly differing thermal stabilities and decomposition mechanisms compared with their non-fluorinated analogues. 1-Ethyl-3-methylimidazolium acetate was observed to largely decompose via an SN2 nucleophilic substitution reaction when under inert gas conditions, predominantly at the imidazolium methyl substituent. The Arrhenius equations for thermal decomposition of 1-ethyl-3-methylimidazolium acetate, and the C2-methylated analogue 1-ethyl-2,3-dimethylimidazolium acetate, were determined from isothermal Thermogravimetric Analysis experiments. The low thermal stability of 1-ethyl-3-methylimidazolium acetate has important implications for biomass experiments employing this ionic liquid. For these two ionic liquids, ion pair and transition state structures were optimised using Density Functional Theory. The activation barriers for the SN2 nucleophilic substitution mechanisms are in good agreement with the experimentally determined values.
- Clough, Matthew T.,Geyer, Karolin,Hunt, Patricia A.,Mertes, Juergen,Welton, Tom
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- Halogen-free ionic liquids and their utilization as cellulose solvents
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This work demonstrates a novel synthesis route to halogen-free ionic liquids. A one-pot synthetic reaction route avoiding the use of toxic and high-energetic alkyl halides was developed to reduce the environmental impact of the synthesis process of ionic liquids. However, the elimination of halogens and alkyl halides in the preparation of ionic liquids is not just an environmental issue: the aforementioned species are also among the most common and persistent contaminants in today's Ionic Liquids (ILs). Thus, this paper introduces a range of quaternized nitrogen based ionic liquids, including both aromatic and non-aromatic components, all prepared without alkyl halides in any step of the process. Moreover, bio-renewable precursors such as (bio-)alcohols and carboxylic acids were employed as anion sources and alkylation media, thus avoiding halogen contamination or halogen-containing anions. The IL's prepared were designed to dissolve cellulose, some of which was included in a cellulose dissolution study using a sulphite cellulose from the company Domsj?.
- Gr?svik, John,Eliasson, Bertil,Mikkola, Jyri-Pekka
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- Ionic fluids containing both strongly and weakly interacting ions of the same charge have unique ionic and chemical environments as a function of ion concentration
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Liquid multi-ion systems made by combining two or more salts can exhibit charge ordering and interactions not found in the parent salts, leading to new sets of properties. This is investigated herein by examining a liquid comprised of a single cation, 1-ethyl-3-methylimidazolium ([C2mim]+), and two anions with different properties, acetate ([OAc]-) and bis(trifluoromethylsulfonyl)imide ([NTf2]-). NMR and IR spectroscopy indicate that the electrostatic interactions are quite different from those in either [C2mim][OAc] or [C2mim][NTf2]. This is attributed to the ability of [OAc]- to form complexes with the [C2mim]+ ions at greater than 1:1 stoichiometries by drawing [C2mim]+ ions away from the less basic [NTf2]- ions. Solubility studies with molecular solvents (ethyl acetate, water) and pharmaceuticals (ibuprofen, diphenhydramine) show nonlinear trends as a function of ion content, which suggests that solubility can be tuned through changes in the ionic compositions.
- Wang, Hui,Kelley, Steven P.,Brantley, Jimmy W.,Chatel, Gregory,Shamshina, Julia,Pereira, Jorge F. B.,Debbeti, Varun,Myerson, Allan S.,Rogers, Robin D.
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- Ionic parachor and its application in acetic acid ionic liquid homologue 1-alkyl-3-methylimidazolium acetate {[Cnmim][OAc](n = 2,3,4,5,6)}
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Five acetic acid ionic liquids (AcAILs) [Cnmim][OAc](n = 2,3,4,5,6) (1-alkyl-3-methylimidazolium acetate) were prepared by the neutralization method and characterized by 1HNMR spectroscopy and differential scanning calorimetry (DSC). The values of their density and surface tension were measured at 298.15 ± 0.05 K. Since the AcAILs can strongly form hydrogen bonds with water, the small amounts of water are difficult to remove from the AcAILs by common methods. In order to eliminate the effect of the trace water, the standard addition method (SAM) was applied to these measurements. As a new concept, ionic parachor was put forward. [OAc] - was seen as a reference ion, and its individual value of ionic parachor was determined in terms of two extrathermodynamic assumptions. Then, the values of ionic parachors of a number of anions, [NTf2] -, [Ala]-, [AlCl4]-, and [GaCl 4]-, were obtained by using the value of the ionic parachor of the reference ion; the parachor and surface tension of the investigated ionic liquids in literature were estimated. In comparison, the estimated values correlate quite well with their matching experimental values.
- Guan, Wei,Ma, Xiao-Xue,Li, Long,Tong, Jing,Fang, Da-Wei,Yang, Jia-Zhen
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- Preparation of corn starch-g-polystyrene copolymer in ionic liquid: 1-Ethyl-3-methylimidazolium acetate
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The copolymer of starch grafted with polystyrene (starch-g-PS) was synthesized with high grafting percentage by utilizing the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) as solvent and potassium persulfate as initiator. The effect of various parameters upon the polymerization were studied including: initiator concentration, styrene:starch weight ratio, the reaction time and temperature. Grafting percentages were calculated using an FT-IR calibration method, with values up to 114%. The resulting copolymer was characterized using FT-IR, SEM, WAXD and TGA, which demonstrated that polystyrene side chains were evenly distributed on the starch backbone. Our results indicate that ionic liquid dissolution of starch, prior to polystyrene grafting, is a versatile methodology for the synthesis of amphiphilic, polysaccharide-based graft copolymers, having high grafting percent.
- Men, Yongjun,Du, Xiyan,Shen, Jianan,Wang, Leli,Liu, Zhengping
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- Simple and recyclable ionic liquid based system for the selective decomposition of formic acid to hydrogen and carbon dioxide
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Exploitation of hydrogen as an energy carrier requires the development of systems for its storage and delivery. Formic acid has been proposed as valuable hydrogen carrier compound, due to its relatively high hydrogen content (53 g L-1), the latter being easily and cleanly released in catalytic reactions under mild conditions (HCOOH → H2 + CO2). Ionic liquids are interesting solvents for homogeneous catalyzed formic acid decomposition systems as their extremely low volatility avoids solvent contamination of the produced hydrogen stream. In this paper an outstandingly simple, robust and active catalyst system is presented, namely RuCl3 dissolved in 1-ethyl-2,3-dimethylimidazolium acetate (RuCl3/[EMMIM] [OAc]). This system proved to be fully recyclable over 10 times. Turnover frequencies (TOF) of 150 h-1 and 850 h-1 were obtained at 80 °C and 120 °C, respectively.
- Berger,Assenbaum,Taccardi,Spiecker,Wasserscheid
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- Nonaqueous lyotropic ionic liquid crystals: Preparation, characterization, and application in extraction
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A class of new ionic liquid (IL)-based nonaqueous lyotropic liquid crystals (LLCs) and the development of an efficient IL extraction process based on LC chemistry are reported. The nonaqueous LLCs feature extraordinarily high extraction capacity, excellent separation selectivity, easy recovery, and biocompatibility. This work also demonstrates that the introduction of self-assembled anisotropic nanostructures into an IL system is an efficient way to overcome the intrinsically strong polarity of ILs and enhances the molecular recognition ability of ILs. The distribution coefficients of IL-based LLCs for organic compounds with H-bond donors reached unprecedented values of 50-60 at very high feed concentrations (>100 mg mL-1), which are 800-1000 times greater than those of common ILs as well as traditional organic and polymer extractants. The IL-based nonaqueous LLCs combining the unique properties of ILs and LCs open a new avenue for the development of high-performance extraction methods. Putting order into ionic liquids: Ionic liquid (IL)-based nonaqueous lyotropic liquid crystals (LLCs) exhibit extraordinarily high extraction capacity, excellent separation selectivity, and easy recycling. The introduction of self-assembled nanostructures into IL systems is an efficient way to enhance the recognition ability for H-bond donor molecules. The IL-based LLCs successfully combine the unique properties of ILs and LCs and provide a new platform for high-performance separation.
- Liu, Xianxian,Yang, Qiwei,Bao, Zongbi,Su, Baogen,Zhang, Zhiguo,Ren, Qilong,Yang, Yiwen,Xing, Huabin
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- Theoretical and experimental investigation of the interactions between [emim]Ac and water molecules
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Density functional theory (DFT) calculations, atom in molecules (AIM) theory, natural bond orbital (NBO) analysis and infrared (IR) spectroscopy were performed to investigate the interactions between water molecules and ionic liquid 1-ethyl-3-methylimidazolium acetate ([emim]Ac). It was found that [emim]Ac interacts with water molecules mainly via H-bonds, and the anionic part of [emim]Ac plays a major role in the interaction with H2O. The energies of H-bonds were estimated from spectral shifts of hydroxy antisymmetric stretching vibration. Moreover, the experimental results also indicated that hydroxy of water mainly interacts with the COO- of [emim]Ac. Further studies indicated that the intensity of hydroxy stretching vibrations tend to be stronger with the increase of the concentration of water. In addition, the frequency of hydroxy stretching vibrations showed clearly red-shift, and the COO- vibrational frequency gradually shifted to the lower wavenumber region, which were indicative of extended hydrogen bonded network.
- Ding, Zhen-Dong,Chi, Zhen,Gu, Wen-Xiu,Gu, Sheng-Ming,Wang, Hai-Jun
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- Bronsted acids in ionic liquids: How acidity depends on the liquid structure
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Gutmann Acceptor Number (AN) values have been determined for Bronsted acid-ionic liquid mixtures, over a wide compositional range. Four systems of general formula [C2mim][A]-HA (A- = bistriflamide, [NTf2]-; triflate, [OTf]-; mesylate, [OMs]-; or acetate, [OAc]-, [C2mim]+ = 1-ethyl-3-methylimidazolium cation) were studied. A library of Bronsted acidic systems of varying acidity was constructed and the AN parameter was found to be a convenient approach for quantifying their acidity. HOAc, HOMs and HOTf, when dissolved in ionic liquids, were found to associate with the respective anions to form hydrogen-bonded anionic clusters, [A(HA)x]-. In contrast, HNTf2 was solubilised as a discrete, undissociated molecule. AN values were sensitive to the presence of anionic clusters; acidity could be buffered to a particular AN by binding the solubilised acid in the anionic cluster form. Overall, a simple way to manipulate and quantify the Bronsted acidity of acid-ionic liquid mixtures was demonstrated, and measured AN values were related to liquid speciation. This journal is
- McCune, Jade A.,He, Peizhao,Petkovic, Marina,Coleman, Fergal,Estager, Julien,Holbrey, John D.,Seddon, Kenneth R.,Swadba-Kwasny, Malgorzata
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- Organocatalytic upgrading of the key biorefining building block by a catalytic ionic liquid and N-heterocyclic carbenes
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The present study of rapid degradation of the key biorefining building block 5-hydroxymethylfurfural (HMF) in an ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), has led to highly selective and efficient upgrading of HMF to 5,5′-di(hydroxymethyl)furoin (DHMF), a promising C12 kerosene/jet fuel intermediate. This HMF upgrading reaction is carried out under industrially favourable conditions (i.e., ambient atmosphere and 60-80 °C), catalyzed by N-heterocyclic carbenes (NHCs), and complete within 1 h; this process selectively produces DHMF with yields up to 98% (by HPLC or NMR) or 87% (unoptimized, isolated yield). Mechanistic studies have yielded four lines of evidence that support the proposed carbene catalytic cycle for this upgrading transformation catalyzed by the acetate IL and NHCs.
- Liu, Dajiang,Zhang, Yuetao,Chen, Eugene Y.-X.
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- An environmental friendly approach for the synthesis of the ionic liquid 1-ethyl-3-methylimidazolium acetate and its dissolubility to 1, 3, 5-triamino-2, 4, 6-trinitrobenzene
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The ionic liquid 1-ethyl-3-methylimidazolium acetate ([Emim] Ac) is a good solvent for the famous insensitive high explosive 1,3,5-triamino-2,4,6- trinitrobenzene (TATB). In this work, a novel one-pot method has been proposed to synthesize [Emim] Ac using 1-methylimidazole and bromethyl as starting materials, and the reaction conditions have been optimized experimentally. Results show that the one-pot method has advantages of high yield and easy purification process. The synthesized [Emim] Ac has been successfully used to recrystallize TATB, whose exothermic peak increases from 382.9°C to 392.1°C, imply that the purity of recycled TATB is higher. In addition, the dissolution mechanism of TATB in the ionic liquid has been analyzed based on FTIR spectra.
- Zhu,Li,Xu,Yang
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- Water sorption by ionic liquids: Evidence of a diffusion-controlled sorption process derived from the case study of [BMIm][OAc]
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The hydrophilicity of ionic liquids (ILs) could be exploited as desiccants or in sorption-driven heat transformation, yet reports of water sorption isotherms of pure ionic liquids are still scarce. Here, water sorption studies for the six pure hydrophilic ionic liquids with 1-ethyl-3-methylimidazolium [EMIm]+ or 1-butyl-3-methylimidazolium [BMIm]+ cations and acetate [OAc]?, formate [HCOO]? or lactate [Lac]? anions show a steady and high water uptake with a small hysteresis between absorption and desorption over the relative pressure range of p/p0 = 0 – 0.9 for the first time. Repeated static volumetric sorption measurements with different amounts or different surface area of the example IL [BMIm][OAc] reveal a slow and strongly diffusion-driven sorption process stemming from the absorption of surface-adsorbed water into the bulk IL. Extrapolation of the water uptake to very small IL amounts with negligible kinetic hindrance gives an equilibrium water uptake capacity of over 2100 mg/g(IL) at p/p0 = 0.9. Gravimetric control experiments at a relative humidity of 75.5 % confirm the time-dependence with the IL surface area at the gas–liquid-interface and the amount of the IL to reach the equilibrium uptake of 1040 mg/g at p/p0 = 0.75.
- Brandt, Philipp,Janiak, Christoph,Schmitz, Alexa,Spie?, Alex
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- Ready Access to Anhydrous Anionic Lanthanide Acetates by Using Imidazolium Acetate Ionic Liquids as the Reaction Medium
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Access to lanthanide acetate coordination compounds is challenged by the tendency of lanthanides to coordinate water and the plethora of acetate coordination modes. A straightforward, reproducible synthetic procedure by treating lanthanide chloride hydrates with defined ratios of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) has been developed. This reaction pathway leads to two isostructural crystalline anhydrous coordination complexes, the polymeric [C2mim]n[{Ln2(OAc)7}n] and the dimeric [C2mim]2[Ln2(OAc)8], based on the ion size and the ratio of IL used. A reaction with an IL : Ln-salt ratio of 5 : 1, where Ln=Nd, Sm, and Gd, led exclusively to the polymer, whilst for the heaviest lanthanides (Dy?Lu) the dimer was observed. Reaction with Eu and Tb resulted in a mixture of both polymeric and dimeric forms. When the amount of IL and/or the size of the cation was increased, the reaction led to only the dimeric compound for all the lanthanide series. Crystallographic analyses of the resulting salts revealed three different types of metal-acetate coordination modes where η2μκ2 is the most represented in both structure types.
- Bousrez, Guillaume,Renier, Olivier,Kelley, Steven P.,Adranno, Brando,Tahavori, Elnaz,Titi, Hatem M.,Smetana, Volodymyr,Tang, Si-Fu,Mudring, Anja-Verena,Rogers, Robin D.
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p. 13181 - 13189
(2021/08/16)
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- Carboxylate ionic liquid as well as preparation method and application thereof
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The invention provides carboxylate ionic liquid as well as a preparation method and application thereof. According to the carboxylate ionic liquid provided by the invention, an imidazole group or a pyridine group is introduced into the cationic part of the carboxylate ionic liquid and a carboxylic acid group is introduced into the anionic part of the carboxylate ionic liquid; and the ionic liquidcatalyst provided by the invention is simple and convenient in synthesis route, high in yield and easy to recover. Anion carboxylate radical in the carboxylate ionic liquid provided by the invention serves as an active site, so that synthesis of diol can be realized through high-efficiency and high-selectivity catalysis of hydration reaction of epoxy compounds under the condition of not adding other catalysts.
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Paragraph 0120; 0123; 0127-0129
(2019/10/23)
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- Preparing method of high-purity imidazole acetate ionic liquid
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The invention belongs to the technical field of ionic liquid synthesis, and particularly relates to a preparing method of high-purity imidazole acetate ionic liquid. The method includes the steps of making a 1-alkyl-3-methylimidazole halogenated product react with lithium perchlorate to obtain a high-purity 1-alkyl-3-methylimidazole perchlorate ionic liquid intermediate, and then conducting replacement reaction on the intermediate and potassium acetate or ammonium acetate to obtain the 1-alkyl-3-methylimidazole acetate ionic liquid. The raw materials are low in price and easy to obtain, the raw materials or middle byproducts are free of heavy metals or other pollutions, reaction is thorough, the reaction yield is 90.0% or above, the product purity is 99.0% or above, the content of halogenresidues in the product is smaller than or equal to 5 ppm, and the content of K ions or ammonium radicals in the product is 200 ppm or below.
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Paragraph 0051-0053
(2019/10/15)
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- Synthesis of propylene glycol ethers from propylene oxide catalyzed by environmentally friendly ionic liquids
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A series of acetate ionic liquids were synthesized using a typical two-step method. The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and alcohols under mild conditions. The basic strengths of the ionic liquids were evaluated by determination of their Hammett functions, obtained using ultraviolet-visible spectroscopy, and the relationship between their catalytic activities and basicities was established. The catalytic efficiencies of the ionic liquids were higher than that of the traditional basic catalyst NaOH. This can be attributed to the involvement of a novel reaction mechanism when these ionic liquids are used. A possible electrophilic-nucleophilic dual activation mechanism was proposed and confirmed using electrospray ionization quadrupole time-of-flight mass spectrometry. In addition, the effects of significant reaction parameters such as concentration of catalyst, molar ratio of alcohol to propylene oxide, reaction temperature, and steric hindrance of the alcohol were investigated in detail.
- Zhao, Cong,Chen, Shengxin,Zhang, Ruirui,Li, Zihang,Liu, Ruixia,Ren, Baozeng,Zhang, Suojiang
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p. 879 - 888
(2017/05/24)
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- Evidence for the spontaneous formation of N-heterocyclic carbenes in imidazolium based ionic liquids
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We present a study of the reactions of aldehydes in ionic liquids which gives evidence for the spontaneous formation of N-heterocyclic carbenes in ionic liquids based on 1,3-dialkyl substituted imidazolium cations from the lack of a deuterium isotope effect on the reaction of these ionic liquids with aldehydes.
- Daud,Bakis,Hallett,Weber,Welton
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supporting information
p. 11154 - 11156
(2017/10/17)
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- Method for preparing fructosazine by utilizing chitin-based biomass
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The invention relates to a method for preparing fructosazine by utilizing chitin-based biomass. The method comprises the following steps: adding a dry chitin-based biomass raw material, an imidazolium ionic liquid solution and an additive to dimethyl sulfoxide to obtain a mixture; uniformly mixing the obtained mixture to perform a reaction, wherein the mass ratio of the imidazolium ionic liquid to the chitin-based biomass raw material is 1: (2-100), and the mass ratio of the added chitin-based biomass raw material to an oxidant is 1: (1-50) to obtain an intermediate product; adding a crystallization solvent to the intermediate product, wherein the volume ratio of the intermediate product to the solvent is 1: 1 to 1: 10; completely dissolving the product; removing undissolved impurities to obtain a filter liquor; carrying out rotary evaporation concentration on the filter liquor; standing; and recrystallizing to prepare the final product. The method has the advantages of wide raw material resources, no pollution, simple preparation and high product purity.
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Paragraph 0032; 0033
(2016/10/07)
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- Method for preparing deoxyfructosazine through chitin biomass
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A method for preparing deoxyfructosazine through chitin biomass comprises the following steps: uniformly mixing a dry chitin biomass raw material, an imidazole ionic liquid solution and an additive in a dimethyl sulfoxide reaction medium for reaction to obtain an intermediate product; adding a crystal solvent in the intermediate product to completely dissolve the product, performing hot filtration to remove insoluble impurities, performing rotary evaporation concentration on a filtrate, and performing recrystallization to obtain the product, namely the deoxyfructosazine. The method has the advantages that the raw material source is wide, pollution is avoided, the preparation is simple, and the product purity is high.
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Paragraph 0032
(2017/01/26)
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- Efficient ionic liquid synthesis method
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The invention relates to an efficient ionic liquid synthesis method. The efficient ionic liquid synthesis method is characterized in that an ultrasonic and microwave synergistic heating manner is adopted in an ionic liquid synthesis process. Through the new method adopting the ultrasonic and microwave synergistic heating manner to synthetize the ionic liquid, the reaction time is shortened, the reaction temperature is reduced, the energy consumption is reduced, and the obtained target product, namely the ionic liquid, is high in purity and less in by-product, and has a potential possibility of large scale popularization.
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Paragraph 0013; 0014; 0015
(2017/01/02)
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- ONIUM SALT, LIQUID COMPOSITION CONTAINING SAID ONIUM SALT AND CELLULOSE, AND CELLULOSE RECOVERY METHOD
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The invention relates to an onium salt, a liquid composition containing the onium salt and cellulose, and a method for recovering cellulose. The invention makes it possible to provide an onium salt having an extremely high ability to dissolve cellulose at temperatures of 100° C. or lower. It also makes it possible to provide a liquid composition containing this onium salt and cellulose, as a composition suitable for the recovery of cellulose, and a method for recovering cellulose efficiently by using such a liquid composition containing the onium salt and cellulose.
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Paragraph 0146; 0147; 0148; 0188
(2016/02/19)
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- 1,3-Dimethylimidazolium-2-carboxylate: A zwitterionic salt for the efficient synthesis of vicinal diols from cyclic carbonates
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The development of efficient, cheap and recyclable catalysts for reactions under mild reaction conditions is a very attractive topic in green chemistry. Herein, a series of basic ionic liquids (ILs) were investigated as catalysts for the synthesis of vicinal diols via the hydrolysis of cyclic carbonates in order to improve this kind of synthetic process. The effects of the IL structure, the molar ratio of cyclic carbonate to water, and various reaction parameters on the catalytic performance were investigated in detail. It was found that 1,3-dimethylimidazolium-2-carboxylate, a simple halogen-free zwitterionic catalyst, showed high activity (a space-time yield of 1086 h-1) and excellent selectivity for the preparation of ethylene glycol via the hydrolysis of ethylene carbonate. The catalyst could be reused over six times without obvious loss of catalytic activity. Also, it was applicable to a variety of cyclic carbonates for the production of their corresponding vicinal diols with high yields and selectivities. A possible catalytic cycle for this kind of catalytic process was proposed based on the experimental results, NMR spectroscopy and theoretical calculations. This reaction protocol opens a new possibility for chemical synthesis as a substitution for traditional base or basic ILs. This journal is the Partner Organisations 2014.
- Sun, Jian,Yao, Xiaoqian,Cheng, Weiguo,Zhang, Suojiang
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supporting information
p. 3297 - 3304
(2014/06/10)
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- Esterification of carboxylate-based ionic liquids with alkyl halides
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A facile reaction of 1-ethyl-3-methylimidazolium acetate ([EMIm]Ac) with dichloromethane at room temperature was observed with esters among the products. This esterification can be exploited for mild solvent-free esterification with a range of other carboxylate-based ionic liquids and alkyl halides. The Royal Society of Chemistry.
- Zhao, Bin,Greiner, Lasse,Leitner, Walter
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body text
p. 2973 - 2975
(2011/04/24)
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- Reaction of elemental chalcogens with imidazolium acetates to yield imidazole-2-chalcogenones: Direct evidence for ionic liquids as proto-carbenes
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Mechanistic analysis of the reaction between elemental sulfur or selenium and 1,3-dialkylimidazolium acetate ionic liquids, in the absence of an external base or solvent, affords evidence for the equilibrium presence of carbene species in these ionic liqu
- Rodriguez, Hector,Gurau, Gabriela,Holbrey, John D.,Rogers, Robin D.
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supporting information; experimental part
p. 3222 - 3224
(2011/05/07)
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- METHOD FOR THE PRODUCTION OF DISUBSTITUTED IMIDAZOLIUM SALTS
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Process for preparing 1,3-disubstituted imidazolium salts of the formula I where R1 and R3 are each, independently of one another, an organic radical having from 1 to 20 carbon atoms, R2, R4 and R5 are each, independently of one another, an H atom or an organic radical having from 1 to 20 carbon atoms, X is the anion of a hydrogen acid having a pKa of at least 2 (measured at 25° C., 1 bar in water or dimethyl sulfoxide) and n is 1, 2 or 3, wherein a) an α-dicarbonyl compound, an aldehyde, an amine and the hydrogen acid of the anion X? are reacted with one another and b) the reaction is carried out in water, a solvent which is miscible with water or a mixture thereof.
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Page/Page column 5
(2010/10/19)
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- Method for the production of compounds with quaternary sp2-hybridised nitrogen atoms
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Process for preparing ionic compounds comprising cations containing quaternary sp2-hybridized nitrogen atoms, which comprises reacting compounds containing a double-bonded nitrogen atom with a dialkyl sulfate with participation of both alkyl groups of the dialkyl sulfate and, if appropriate, subjecting the resulting ionic compound containing sulfate anions to an anion exchange.
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- METHOD FOR PRODUCING HETEROCYCLIC QUATERNARY AMMONIUM AND/OR GUANIDINIUM COMPOUNDS
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The invention relates to a method for producing an intermediate product containing a heterocyclic quarternary ammonium and/or guanidium cation, for the synthesis of heterocyclic quaternary ammonium and/or guanidium compounds. According to said method, heterocyclic quaternary ammonium and/or guanidium carboxylates are oxidised with an oxidising agent in the presence of a metal from groups 8 to 10 of the periodical table, at a temperature of between 0 and 250 °C and a pressure of between 0.05 and 20 MPa abs.
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Page/Page column 32-33
(2008/06/13)
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- METHOD FOR THE PRODUCTION OF HETEROCYCLIC QUATERNARY AMMONIUM COMPOUNDS AND/OR GUANIDINE COMPOUNDS HAVING HIGH PURITY
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A method for the production of heterocylic quaternary ammonium compounds and/or guanidine compounds, wherein the carboxylate of the corresponding heterocyclic quaternary ammonium cation and/or guanidine cation containing the carboxylate anion of general formula R'-COO- (I), wherein R' represents hydrogen; C1- C7-alkyl; -OOC-(CH2)n- wherein n is equal to 0, 1 or 2; R"OOC-(CH2)n- wherein n is equal to 0, 1 or 2; -OOC-CH=CH-; R"OOC-CH=CH-; ethenyl; 2-propenyl; or a phenyl group which is unsubstituted or substituted by one to five independently selected groups from the series of C1- C6-alkyl, hydroxy, carboxylate (-COO-), carboxy (-COOH) and C1- C6- alkyloxy carbonyl (-COOR# wherein R# equals C1 - C6-alkyl) and R" equals hyrogen or C1- C6-alkyl; is reacted with an inorganic or organic protonic acid with a pKa-value of von 14 measured at 25 °C in an aqueous solution.
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Page/Page column 32-33
(2008/06/13)
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- MEHTOD FOR PRODUCING IONIC LIQUIDS
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The invention relates to a method for producing ionic liquids consisting first in reacting an ionic liquid with an alkylate, a hydrogencarbonate, a carbonate, a carboxylate or a hydroxide and, afterwards in neutralising with an acid. The inventive ionic liquids contain a phoshonium and/ or ammonium cation and an anion selected from a group comprising halogenides, aryl sulfonates, alkyl sulfonates, sulphates, hydroxysulfats, alkylsulfates, hydrogencarbonates, carbonates, triflates and carboxylates. The inventive method makes it possible to introduce any desired anion into the ionic liquids.
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Page/Page column 22-23
(2010/02/13)
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- METHOD FOR THE PRODUCTION OF COMPOUNDS WITH QUATERNARY SP2-HYBRIDISED NITROGEN ATOMS
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The invention relates to a method for the production of an ionic compound, comprising at least one cation with a quaternary sp2-hybridised nitrogen atom, whereby a compound with a double-bonded nitrogen atom is reacted with a dialkyl sulphate, using both alkyl groups of the dialkyl sulphate and the ionic compound thus obtained with sulphate anions is optionally subjected to an ion-exchange.
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Page/Page column 18
(2008/06/13)
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- METHOD FOR THE PRODUCTION OF PURIFIED 1,3-SUBSTITUTED IMIDAZOLIUM SALTS
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Disclosed is a method for producing purified 1,3-substituted imidazolium salts of general formula (I) by reacting a 1,3-substituted imidazolium salt of general formula (II) with a strong base at a temperature ranging between 20 and 250 °C while distilling off the formed 1,3-substituted imidazol-2-ylidene. According to the inventive method, the distilled 1,3-substituted imidazol-2-ylidene is contacted in a gaseous state with the protonic acid HaA (III), and/or the distilled 1,3-substituted imidazol-2-ylidene is directed in a gaseous or condensed state into a distillation receiver containing said protonic acid HaA (III).
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Page/Page column 22
(2008/06/13)
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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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