- Fluid-phase behavior of {1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, [C6mim][NTf2], + C2-C8 n-alcohol} mixtures: Liquid-liquid equilibrium and excess volumes
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In the frame of the IUPAC Project entitled Thermodynamics of ionic liquids, ionic liquid mixtures, and the development of standarized systems, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, [C 6mim][NTf2], was selected as the model ionic liquid to perform round-robin measurements on a series of ionic liquid properties. In this work, the temperature-composition liquid-liquid equilibria of this ionic liquid with linear alkan-1-ols, CnH(2n+1)OH, with n = 4, 5, 6, and 8, were determined at a nominal pressure of 0.1 MPa and up to 50 MPa for n = 4, 5, and 6. Excess molar volumes, VE, of mixtures of this same ionic liquid with linear alkan-1-ols, CnH 2n+1OH, with n ranging from 2 to 5, were measured at a nominal pressure of 0.1 MPa. The consistency between the two sets of experimental data (phase diagrams and VE) was analyzed from a theoretical perspective; we noticed that as the alkyl chain length, n, of the linear alcohol varies both the pressure dependence of the phase diagrams and the critical excess molar volume change sign.
- Lachwa, Joanna,Morgado, Pedro,Esperanca, Jose M. S. S.,Guedes, Henrique J. R.,Canongia Lopes, Jose N.,Rebelo, Luis Paulo N.
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- Synthesis and properties of symmetrical N,N′-bis(alkyl)imidazolium bromotrichloroferrate(III) paramagnetic, room temperature ionic liquids with high short-term thermal stability
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A series of paramagnetic ionic liquids (PILs) based on N,N′-bis(alkyl)imidazolium bromotrichloroferrate(III), [(Cn)2Im][FeCl3Br] (Im = imidazole; Cn = ethyl, butyl, hexyl, octyl, decyl, dodecyl), was prepared and compared against the more traditional [CnC1Im][FeCl3Br] (C1 = methyl) analogs. Both series were extensively characterized by physical, chemical, and computational methods including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), spectroscopy (FTIR and UV‐vis-NIR), magnetic susceptibility, surface tensiometry, density, and viscosity. The X-ray crystal structure of [(C12)2Im][FeCl3Br] was also obtained. Notably, all ionic liquids prepared in this study show short-term thermal stabilities exceeding 300 °C in air and have melting points equal to or lower than 25 °C, which is surprisingly low for ionic liquids containing symmetrical cations. In addition, all presented ionic liquids have relatively low viscosities allowing for easier transitioning into applications. Physical property trends are discussed.
- Greeson, Kevin T.,Hall, Nicolas G.,Redeker, Neil D.,Marcischak, Jacob C.,Gilmore, Laina V.,Boatz, Jerry A.,Le, Tammy C.,Alston, Jeffrey R.,Guenthner, Andrew J.,Ghiassi, Kamran B.
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- A rapid dispersive liquid-liquid microextraction based on hydrophobic deep eutectic solvent for selective and sensitive preconcentration of thorium in water and rock samples: A multivariate study
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Thorium [Th(IV)] and its compounds are highly toxic and cause severe damage to bone and kidney through long term exposures. Conventional methods of Th(IV) detection are complicated and costly. In this study, we developed a new dispersive liquid-liquid microextraction (DLLME) based on hydrophobic deep eutectic solvent (HDES) for preconcentration of Th(IV) in water and rock samples prior to UV–Vis. spectrophotometric detection. The microextraction procedure was carried out by applying thorin as a chelating agent, cethyltrimethyl ammonium bromide (CTAB) as an ion pairing agent and a DES consisted of 1-hexyl-3-methylimidazolium and salicylic acid components as an extraction solvent. Central composite design (CCD) was applied to obtain the best condition of the microextraction procedure. The developed method is a green, facile, fast, selective and sensitive that could detect Th(IV) in the concentration range of 10–600 ng mL?1 with a limit of detection (LOD) and preconcentration factor of 2.1 ng mL?1 and 59, respectively. The relative standard deviation of five replicate measurements of Th(IV) at 100 ng mL?1 was 1.7%. Finally, the proposed method was successfully applied to the analysis of Th(IV) in water and rock samples, and desirable results were obtained.
- Sadeghi,Davami, Abdolbaset
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- Kinetics and solvent effects in the synthesis of ionic liquids: Imidazolium
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Ionic liquids (ILs) are being considered as a promising class of potentially environmentally-friendly ("green") solvents and materials for use in a variety of applications. However, ionic liquids are conventionally synthesized by batch, without known kine
- Schleicher, Jay C.,Scurto, Aaron M.
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- Exploration of the solvation behavior of the synthesized 1-hexyl-3-methylimidazolium bromide [C6mim][Br] ionic liquid with L-cysteine and N-acetyl L-cysteine) in aqueous medium at different temperatures
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The interactions of L-cysteine and N-acetyl L-cysteine with imidazolium-based ionic liquid 1-hexyl-3-methylimidazolium bromide [C6mim] [Br] as a function of temperature have been studied by a combination of volumetric and acoustic properties. Densities and speeds of the sound of L-cysteine and N-acetyl L-cysteine in (0.00, 0.005, 0.01, 0.03 and 0.05) mol.kg?1 aqueous solutions of 1-hexyl-3-methylimidazolium bromide have been measured at T = (288.15, 298.15, 308.15 and 318.15) K. From density data, the apparent molar volume (V?) the partial molar volume (V?0) and standard partial molar volumes of transfer (ΔV?0) for L-cysteine and N-acetyl L-cysteine from water to aqueous 1-hexyl-3-methylimidazolium bromide solutions have been calculated. Partial molar isentropic compression (K?,s) and partial molar isentropic compression of transfer (ΔK?, S0) have been calculated from the speed of sound data. The pair and triplet interaction coefficient have been calculated from both these properties. The parameters obtained have been used to describe the results in terms of (solute-solute), (solute-solvent) interactions, structure building and structure floating behavior of amino acids in aqueous 1-hexyl-3-methylimidazolium bromide solutions.
- Kumar, Harsh,Sharma, Ravinder,Kumar, Vaneet,Alothman, Asma A.
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- Solvent-free sonochemical synthesis and antifungal activity of 1-alkyl-3-methylimidazolium bromide [RMIM]Br ionic liquids
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In view of the continuous threat of opportunistic fungal infections to human health and the emerging importance of ionic liquids in therapeutic applications, we report the efficient one-pot synthesis of a series of 1-alkyl-3-methylimidazolium bromide [RMIM]Br ionic liquids through an ultrasound-assisted reaction of 1-methylimidazole and alkyl bromides (RBr) under solvent-free conditions. High product yields were obtained for all syntheses (>95%) under mild conditions (2-5 hours at 20-40 °C). The success of the synthetic method was confirmed through 1H-NMR, 13C-NMR and FT-IR spectroscopy. All products exhibited activity against the fungus C. albicans with clotrimazole and water as positive and negative controls, respectively. At a concentration of 1%, [OMIM]Br IL exhibited an antimycotic activity with an index of 1.5 which is comparable to that of 1% clotrimazole having an antimicrobial index of 1.3, signifying the potential of the product as a fungal growth inhibitor. Structure-Activity Relationship (SAR) studies showed that an increase in the alkyl chain length corresponds to an increase in the antifungal activity of the ionic liquids.
- Perez, Ser John Lynon P.,Arco, Susan D.
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- Deciphering aggregation behavior and thermodynamic properties of anionic surfactant sodium hexadecyl sulfate in aqueous solutions of ionic liquids [C5mim][Br] and [C6mim][Br]
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The present work aims to study the interactions of cationic imidazolium based ionic liquids i.e. 1-alkyl-3-methylimidazolium bromide ([Cnmim][Br], where n = 5 &6) with anionic surfactant sodium hexadecyl sulfate (SHS) in aqueous media employing the various techniques such as conductivity measurement, fluorescence spectroscopy, UV–visible spectroscopy and FT-IR spectroscopy. The temperature dependence of critical micelle concentration (CMC) determined using conductivity measurements at temperatures (298.15, 303.15 and 308.15) K at different concentrations (0.02, 0.05 and 0.1) wt. %, of ionic liquids (ILs) in aqueous medium was used to calculate the various thermodynamic parameters of micellization such as, standard free energy of micellization (ΔGm 0), standard enthalpy of micellization (ΔHm 0), and standard entropy of micellization (ΔSm 0). Further, fluorescence and UV–Visible spectroscopy have been utilized to confirm the CMC values obtained from conductivity measurements, which were found to be in good agreement. A continuous increment in CMC value was observed with the increase in concentration of ILs as well as in temperature. Further FT-IR Spectroscopic studies have been done to demonstrate the structural alterations occurring in the respective mixtures.
- Kumar, Harsh,Kaur, Gagandeep
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- Chromium speciation using task specific ionic liquid/aqueous phase biphasic system combined with flame atomic absorption spectrometry
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In this work, 1-alkyl-3-methylimidazolium based ionic liquids combined with salicylate or thiosalicylate anions as task specific ionic liquids were used to form a stable ionic liquids (IL)/aqueous biphasic systems for extraction of Cr(III) and Cr(VI) spec
- Sadeghi, Susan,Moghaddam, Ali Zeraatkar
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- Light-modulated aggregation behavior of some unsubstituted cinnamate-based ionic liquids in aqueous solutions
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Light modulation of the self-assembly behavior of ionic liquids in aqueous solution is of great importance from the viewpoint of fundamentals and technology. In this work, a new class of light-responsive ionic liquids composed of 1-alkyl-3-methylimidazolium cations, [Cnmim]+ (n = 4, 6, 8, 10, 12), and the trans-cinnamic acid ([CA]) anion was synthesized and characterized. These compounds were used to study the modulation action of UV light on the aggregation behavior of ionic liquids in aqueous solution. For this purpose, the critical aggregation concentration (CAC), ionization degree of the aggregates (α), standard Gibbs energy of aggregation (ΔG°m) and aggregate size of the ionic liquids were determined before and after UV light irradiation by conductivity and dynamic light scattering techniques. The percentage of cis-isomer of these ionic liquids was also reported at the photoisomerism equilibrium from HPLC measurements. It was found that the aggregation behavior of [Cnmim][CA] (n = 8, 10, 12) could be efficiently modulated by UV light in aqueous solution. After UV light irradiation, the values of CAC, α and ΔG°m increased, while the size of the aggregates decreased. These results have been rationalized from the photo-isomerization of the [CA] anion, hydrophilicity and structural features of the cis-isomer of the [CA] anion.
- Yang, Jie,Wang, Huiyong,Wang, Jianji,Guo, Xiaojia,Zhang, Yue
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- Structure of the room-temperature ionic liquid/SiO2 interface studied by sum-frequency vibrational spectroscopy
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In the study presented here, the structure of the RTIL/SiO2 interface has been examined by sum-frequency vibrational spectroscopy (SFVS). A series of hydrophobic RTILs composed of l-alkyl-3-methylimidazolium (C nmim, n = 6, 8 and 10) and bis(perfluoromethylsulfonyl)imide (BMSI) and bis(perfluoroethylsulfonyl)imide (BETI) anions have been examined. SFVS was used to determine the orientation of the cation as well as the structure of water at the RTIL/SiO2 interface. The alkyl chain of the imidazolium cation was determined to be nearly normal to the surface for all the RTILs examined. The conformational order of the alkyl chain on the cation was also determined and was found to be dependent on the length of the alkyl chain, with longer chains being more ordered with few gauche defects. The tilt of the imidazolium ring with respect to the surface normal was also determined and was found to be a??28?° for the BMSI salts with a reduction in the tilt angle to a??18?° for the BETI RTILs. The water at the surface associated with the RTIL was determined to be hydrogen-bonded either singly or doubly to the anions at the SiO2 interface. In addition, the nature of the hydrogen-bonding was found to be dependent on the amount of bulk water contained in the RTIL.
- Fitchett, Brian D.,Conboy, John C.
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- Interaction between Ionic Liquids and Gemini Surfactant: A Detailed Investigation into the Role of Ionic Liquids in Modifying Properties of Aqueous Gemini Surfactant
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Tuning physicochemical properties of aqueous surfactant solutions comprised of normal or reverse micelles by external additives is of utmost importance due to the enormous application potential of surfactant-based systems. Unusual and interesting properties of environmentally benign ionic liquids (IL) make them suitable candidates for this purpose. To understand and establish the role of IL in modifying properties of aqueous gemini surfactants, we studied the effect of the IL, 1-hexyl-3-methylimidazolium bromide ([Hmim][Br]) and 1-octyl-3-methylimidazolium bromide ([Omim][Br]) on the properties of the aqueous cationic gemini surfactant 1,6-hexanediyl-α,ω-bis(dimethyltetradecyl)ammonium bromide (14-6-14,2Br-). The behavioral changes were investigated by measuring the critical micelle concentration (CMC) using electrical conductance, surface tension, dye solubilization and fluorescence probe measurements at 298.15 K. It was observed that the CMC of 14-6-14,2Br- gemini surfactant decreases with addition of IL, thus favoring the micellization process. An increase in micellar size was observed at lower IL concentration using dynamic light scattering, with a decrease in aggregation number (N agg) determined from fluorescence probe quenching measurements. It is noteworthy that the extent of modulation of the micellar properties is different for both the IL due to their structural differences. IL behave like electrolytes at lower concentrations and cosurfactants at higher concentrations and form mixed micelles with the cationic gemini surfactant showing an increase in N agg.
- More, Utkarsh,Kumari, Pallavi,Vaid, Zuber,Behera, Kamalakanta,Malek, Naved I.
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- Synthesis and biological evaluation of some novel 1-alkyl-3-methylimidazolium carboxylate ionic liquids as potential antifungal agents
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In an effort to discover lead compounds that may be of importance as potent antifungal agents, a series of novel 1-alkyl-3-methylimidazolium carboxylate ionic liquids were efficiently synthesized through a solvent-free ultrasound-assisted quaternization reaction of 1-methylimidazole and alkyl bromides RBr (R = hexyl, octyl) followed by an anion exchange process with selected carboxylate anions (cinnamate, salicylate, crotonate, and oxalate). Quantitative yields obtained were in the range of 86–94%. Structure characterization was done using FT-IR, 1H-NMR, and 13C-NMR spectroscopic techniques. All the synthesized compounds showed in vitro antifungal activity against the fungus Candida albicans with the minimum inhibitory concentrations found to be less than or equal to 1%. Preliminary cytotoxicity assays (trypan blue exclusion and MTT) were performed on all ionic liquids and findings revealed higher lymphocyte viability in 1-hexyl-3-methylimidazolium carboxylate ionic liquids than in 1-octyl-3-methylimidazolium counterparts. No extensive toxicity effect was observed with the carboxylate anion variation. Among the tested compounds, 1-hexyl-3-methylimidazolium crotonate and 1-hexyl-3-methylimidazolium oxalate exhibited the lowest cytotoxicity in the trypan blue exclusion and MTT assays, respectively. Together, our results highlight the potential of carboxylate-based ionic liquids in the development of next-generation antifungal drugs.
- Perez, Ser John Lynon P.,Atayde, Eduardo C.,Arco, Susan D.
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- New ionic liquids with fluorous anions for supported liquid membranes and characterization
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This article reports the synthesis and the characterization of novel fluorous ionic liquids with fluorous anions to be used as carrier for fluorous supported liquid membrane in view of future applications to the extraction of metal ions. Dialkylimidazoliu
- Jean, Etienne,Villemin, Didier,Lebrun, Laurent
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- Ionic liquid as plasticizer for europium(iii)-doped luminescent poly(methyl methacrylate) films
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Flexible luminescent polymer films were obtained by doping europium(iii) complexes in blends of poly(methyl methacrylate) (PMMA) and the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C 6mim][Tf2N]. Different europium(iii) complexes have been incorporated in the polymer/ionic liquid matrix: [C6mim][Eu(nta) 4], [C6mim][Eu(tta)4], [Eu(tta) 3(phen)] and [choline]3[Eu(dpa)3], where nta is 2-naphthoyltrifluoroacetonate, tta is 2-thenoyltrifluoroacetonate, phen is 1,10-phenanthroline, dpa is 2,6-pyridinedicarboxylate (dipicolinate) and choline is the 2-hydroxyethyltrimethyl ammonium cation. Bright red photoluminescence was observed for all the films upon irradiation with ultraviolet radiation. The luminescent films have been investigated by high-resolution steady-state luminescence spectroscopy and by time-resolved measurements. The polymer films doped with β-diketonate complexes are characterized by a very intense 5D0 → 7F2 transition (up to 15 times more intense than the 5D0 → 7F 1) transition, whereas a marked feature of the PMMA films doped with [choline]3[Eu(dpa)3] is the long lifetime of the 5D0 excited state (1.8 ms).
- Lunstroot, Kyra,Driesen, Kris,Nockemann, Peter,Viau, Lydie,Mutin, P. Hubert,Vioux, Andre,Binnemans, Koen
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- The effect of 1-N-alkyl chain of ionic liquids [Cnmim] +Br- (n = 2, 4, 6, 8) on the aspect ratio of ZnO nanorods: Syntheses, morphology, forming mechanism, photoluminescence and recyclable photocatalytic activity
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Using a pure ionic liquid-assisted solid-state-like synthesis method under 80 °C, high quality zinc oxide (ZnO) nanorods in 1-alkyl-3-methylimidazolium and bromide anions ionic liquids [Cnmim]+Br- (n = 2, 4, 6, 8) were rea
- Wang, Li,Chang, Li-Xian,Wei, Lian-Qiang,Xu, Shen-Zhi,Zeng, Ming-Hua,Pan, Shi-Lie
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- Physicochemical properties of air and water stable rhenium ionic liquids
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Air and water stable ionic liquids (ILs) based on catalytic functional metal rhenium, [Cnmim][ReO4](n = 2,4,5,6)(1-alkyl-3- methylimidazolium perrhenate), are designed and synthesized. Their density and surface tension are measured i
- Fang, Da-Wei,Wang, Han,Yue, Shuang,Xiong, Ying,Yang, Jia-Zhen,Zang, Shu-Liang
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- Low-temperature heat capacity and standard thermodynamic functions of 1-hexyl-3-methyl imidazolium perrhenate ionic liquid
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Heat capacity for 1-hexyl-3-methyl imidazolium perrhenate ionic liquid [C6MIM][ReO4] in the temperature range from 79 to 396?K has been measured by a fully automated adiabatic calorimeter. For [C6MIM][ReO4], glass transition temperature, the melting temperature, standard molar heat capacity, enthalpy and entropy of solid–liquid phase transition were determined to be (202.164 ± 0.405) K, (226.198 ± 0.265) K, (480.702 ± 0.013) J?K?1?mol?1, (15.665 ± 0.195) kJ?mol?1 and (69.250 ± 0.780) J?K?1?mol?1, respectively. In addition, the thermodynamic characteristics and solid–liquid phase change behavior of [C6MIM][ReO4] were compared with the ones of [C7MIM][ReO4] reported in the literature. The thermodynamic functions (HT? H298.15), (ST? S298.15) and (GT? G298.15), for the compound in the experimental temperature range were calculated.
- Fang, Da-Wei,Liang, Kun-Hao,Hu, Xiao-Hong,Fan, Xiu-Ting,Wei, Jie
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- Thermodynamic study of aspirin in the presence of ionic liquid, 1-hexyl-3-methylimidazolium bromide in acetonitrile at T = (288.15 to 318.15) K
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In recent years, ionic liquids have received much attention in pharmaceutical processing. Thermophysical properties such as densities, viscosities, speeds of sound and refractive indices for systems containing aspirin (ASA), ionic liquid {1-hexyl-3-methyl
- Shekaari, Hemayat,Zafarani-Moattar, Mohammed Taghi,Mirheydari, Seyyedeh Narjes
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- Electrolytic conductivity of four imidazolium-based room-temperature ionic liquids and the effect of a water impurity
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The electrolytic conductivities (κ) of four hydrophobic room-temperature ionic liquids (RTILs) were measured at temperatures from (288.15 to 323.15) K. The measurements were made with a commercial conductivity cell with platinum black electrodes. In order to exclude atmospheric moisture, the conductivity cell was modified so that it could be sealed during measurements. The RTILs studied were 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-3-methylimidazolium hexafluorophosphate. The RTILs were dried under vacuum until the mass fraction of water (wH2O) was ≤10-5. Coulometric Karl Fischer titration was used to determine wH2O in each RTIL before and after measurements of κ. Most measurements were made on dried RTILs, but some measurements were performed intentionally at higher wH2O in order to study the effect of a water impurity on κ. For {water + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide}, κ was found to increase dramatically with increasing wH2O; for example, in going from wH2O=10-5to10-2, the fractional increase in κ was 0.36 {=(κwet - κ dried)/κdried}. This work illustrates the importance of measuring the water content in RTILs both before and after measurements of κ. Published by Elsevier Ltd.
- Widegren, Jason A.,Saurer, Eric M.,Marsh, Kenneth N.,Magee, Joseph W.
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- Interaction between polyethylene oxide and ionic liquid 1-hexyl-3-methyl-imidazolium bromide: Spectroscopic and viscometric methods
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In this research, the type of interactions between polyethylene oxide and 1-hexyl-3-methyl imidazolium bromide was studied by FT-IR and UV-Vis methods. The results of FT-IR and UV-Vis spectroscopy confirmed existence of hydrogen bonding between imidazoliu
- Mehrdad, Abbas,Taghizadeh, Mohammad Taghi,Niknam, Zahra
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- Ionic liquids: Differential scanning calorimetry as a new indirect method for determination of vaporization enthalpies
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Differential scanning calorimetry (DSC) has been used to measure enthalpies of synthesis reactions of the 1-alkyl-3-methylimidazolium bromide [C nmim][Br] ionic liquids from 1-methylimidazole and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The optimal experimental conditions have been elaborated. Enthalpies of formation of these ionic liquids in the liquid state have been determined using the DSC results according to the Hess Law. The ideal-gas enthalpies of formation of [Cnmim][Br] were calculated using the methods of quantum chemistry. They were used together with the DSC results to derive indirectly the enthalpies of vaporization of the ionic liquids under study. In order to validate the indirect determination, the experimental vaporization enthalpy of [C4mim][Br] was measured by using a quartz crystal microbalance (QCM). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of vaporization enthalpies of ionic liquids. ? 2012 American Chemical Society.
- Verevkin, Sergey P.,Emel'Yanenko, Vladimir N.,Zaitsau, Dzmitry H.,Ralys, Ricardas V.,Schick, Christoph
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- Properties of Bromine Fused Salts Based on Quaternary Ammonium Molecules and Their Relevance for Use in a Hydrogen Bromine Redox Flow Battery
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Bromine complexing agents (BCA) in aqueous electrolytes for hydrogen bromine flow batteries are used to reduce bromine‘s vapour pressure, while an insoluble and liquid fused salt is formed. The properties (concentrations, composition, conductivity and viscosity) of this fused salt are investigated in this study systematically ex situ by using 7 BCAs at different state of charge in HBr/Br2/H2O electrolytes with a theoretical capacity of 179.6 Ah L?1. Bromine is stored in the fused salt at concentrations up to 13.6 M, reaching theoretical volumetrical capacities up to 730 Ah L?1 in fused salts. The fused salt consists of a pure, bromine- and water-free ionic liquid of organic [BCA]+ cations and polybromides, and its conductivity bases on a hopping mechanism among the polybromides. Alkyl side chain length of the BCAs and distribution of polybromides influence strongly the conductivity and viscosity of the fused salts. 1-ethylpyridin-1-iumbromide results to be favoured BCA for application.
- Fischer, Peter,Küttinger, Michael,Loichet Torres, Paulette A.,Meyer, Emeline
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supporting information
(2022/02/21)
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- Quantum dots in which ionic liquids are ion-bonded and their preparation method
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A quantum dot particle in which an ionic liquid is ion-bonded is disclosed. The quantum dot particle includes a quantum dot having a core/shell nanostructure; and an ionic liquid compound represented by following Chemical Formula 1, bonded to the surface of the quantum dot, wherein the quantum dot and the ionic liquid compound form an ionic bond: wherein, R1 and R2 are each independently a branched or unbranched hydrocarbon group having 1 to 22 carbon atoms, and X? is a monovalent anion, wherein the hydrocarbon group includes a saturated or unsaturated group and may include one or more hetero atoms.
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- Transition-metal- and phosphorus-free electrophilic trifluoromethylthiolation of indoles with sodium trifluoromethanesulfinates in ionic liquids
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An acid-promoted protocol has been developed to achieve the transition-metal- and phosphorus-free electrophilic trifluoromethylthiolation of indoles using sodium trifluoromethanesulfinates in an imidazolium-based ionic liquid ([Hmim]Br). [Hmim]Br not only acts as a recyclable solvent, but also as the reductant in this transformation. The advantages of this chemistry include simple operation, use of a recyclable solvent, avoidance of transition-metal and phosphorus, and gram-scale synthesis.
- Wang, Fei,Lu, Guo-Ping,Lin, Yamei
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supporting information
(2021/04/12)
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- ZIF-8-porous ionic liquids for the extraction of 2,2,3,3-tetrafluoro-1-propanol and water mixture
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The design of stable ionic liquids (ILs) has become crucial for efficient liquid-liquid extraction (LLE) of alcohol and water. Porous ionic liquids (PILs), as a special class of ILs, have attracted attention by virtue of their unique porous structure and IL characteristics. In this research, a series of zeolitic imidazolate framework-8 based porous ionic liquids (ZIF-8-PILs) were synthesized by simply mixing a solution of zeolitic imidazolate framework-8 (ZIF-8) and rationally designed ILs. The introduction of ZIF-8 resulted in a unique liquid porous structure and molecular sieve for ZIF-8-PILs. The improved extraction properties endowed ZIF-8/[Bpy][NTf2] with more efficiency for the separation of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water with 88.1% TFP extraction rate and steady reuse. The excellent extraction performance of ZIF-8-PILs is discussed in relation to their textural property and unique intermolecular interaction.
- Wang, Zenghui,Zhao, Pingping,Wu, Jimin,Gao, Jun,Zhang, Lianzheng,Xu, Dongmei
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supporting information
p. 8557 - 8562
(2021/05/26)
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- Supramolecular polymeric aggregation behavior and its impact on catalytic properties of imidazolium based hydrophilic ionic liquids
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Ionic Liquids (ILs) self-assemble to form supramolecular polymeric clusters/aggregates. The aggregation behavior of ILs influences its activity in the organic synthesis. However, the precise role of ILs in organic reactions is still unknown. It is, therefore, important to comprehend the supramolecular polymeric aggregation behavior of ILs. We are exploring the supramolecular polymeric aggregation behavior of ILs using Electrospray Ionization Mass Spectrometry (ESI-MS). We have synthesized four hydrophilic ILs (1–4) and investigated their aggregation behavior and its impact on catalytic activity in Carbon-Carbon bond formation (Knoevenagel and Claisen-Schmidt condensation). Here, we show that the aggregation behavior of ILs depends on the type and nature of cation and anion. ESI-MS (?ve) spectra reveals two different type of aggregation i.e. [CnAn+1]? & [A2 + H+]?. We have found that catalytic activity increases with increased [CnAn+1]? supramolecular aggregation. Consequently, highest yield of products obtained in ILs which show decreased anion-anion aggregation [A2 + H+]? abundance in ESI-MS. We anticipate our results to be a starting point for the establishment of desired ILs for organic synthesis.
- Muhammad, Shoaib,Javed, Muhammad Naveed,Ali, Firdous Imran,Bari, Ahmed,Hashmi, Imran Ali
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- Influence of ionic liquid counterions on activity and selectivity of ethylene trimerization using chromium-based catalysts in biphasic media
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In recent years ionic liquids (ILs) have attracted much interest because of their widespread use in various fields. Several trimerization and oligomerization catalysts have been evaluated in ILs with different organic–inorganic hybrid structures. High catalytic activity and selectivity, easy product separation, and recycling of the catalyst are the advantages of a biphasic catalyst system compared to the homogeneous catalysts. In this study, the influence of IL counter-anions on activity and selectivity of the ethylene trimerization catalysts based on Cr-SNS-R was investigated. All synthesized materials were characterized using Fourier-transform infrared spectroscopy, 1H NMR, 13C NMR, UV–Vis. spectroscopy, thin-layer chromatography, and elemental analysis (CHNS). In ethylene trimerization reaction, the dodecyl substituent in the SNS ligand exhibited better activity and selectivity than the butyl substituent. The results revealed that the presence of BF4? as a counter-anion in the IL led to an increase in activity and selectivity compared to Br? and I? counter-anions. It was found that the BF4? counter-anion plays a conclusive role in the development of 1-hexene activity and selectivity to a maximum amount of 71,132 g1-C6/(gCr × h) and more than 99percent, respectively. Finally, the catalyst was reused thrice without losing its 1-hexene selectivity.
- Marefat, Mohamadreza,Ahmadi, Ebrahim,Mohamadnia, Zahra
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- Influence of 1-hexyl-3-methylimidazolium bromide ionic liquid on the volumetric and acoustic properties of amino acids (L-alanine and L-phenylalanine) at different temperatures
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In the present work, solute–solvent interactions in the studied aqueous ternary mixture of ionic liquid 1-hexyl-3-methylimidazolium bromide and amino acids (L-alanine and L-phenylalanine) were determined by using volumetric, acoustic, and spectroscopic pr
- Kumar, Harsh,Sharma, Ravinder
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- Preparation method of 1-R-3-methylimidazolyl ionic liquids with different chain lengths
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The invention discloses a preparation method of 1-R-3-methylimidazolyl ionic liquids with different chain lengths. The preparation method specifically comprises the following steps: step 1, under stirring, carrying out a thermostatic reaction on N-methylimidazole and 1-bromoalkane to obtain a first liquid; step 2, washing the first liquid with ethyl acetate until a supernatant is clear, and takinglower-layer liquid to obtain a second liquid; step 3, purifying the second liquid to obtain a crude product; and step 4, drying the crude product in vacuum to obtain the 1-R-3-methylimidazolyl ionicliquids with different chain lengths. The preparation method has the advantages that the preparation method is simple in process and easy to operate, used reagents are common, and cost is low; and the1-R-3-methylimidazolyl ionic liquids with different chain lengths and relatively high purity are prepared.
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Paragraph 0058-0063
(2020/05/11)
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- The one-pot synthesis of butyl-1H-indol-3-alkylcarboxylic acid derivatives in ionic liquid as potent dual-acting agent for management of BPH
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Based on the SAR of both α1-AR antagonists and 5α-reductase (5AR) inhibitors, the dual-acting agent 4-(1-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-1H-indol-3-yl)butanoic acid 4aaa was designed against BPH and synthesized by two steps of N-alkylation. One-pot protocol towards 4aaa was newly developed. With IL [C6min]Br as solvent, the yield of 4aaa was increased to 75.1% from 16.0% and the reaction time was shortened in 1.5 h from 48 h. 25 derivatives structurally based on arylpiperazine and indolyl butyric acid with alkyl linker were prepared. The protocol was futher extended to get another 14 derivatives wherein O-alkylation was involved, and applied to the synthesis of biologically efficient molecules DPQ and Aripiprazole. Expectedly, compound 4aaa exhibited dual inhibition of α1-AR and 5α-reductase, and exhibited no obvious cytotoxicity against human cells. The pharmacokinetic properties of 4aaa was also determined.
- Chen, Kaixuan,Jiang, Zhenzhou,Liu, Shuwen,Xi, Baomin,Yang, Fubiao,Zeng, Li-Yan,Zeng, Yunong
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- Probing CO2 Reduction Pathways for Copper Catalysis Using an Ionic Liquid as a Chemical Trapping Agent
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The key to fully leveraging the potential of the electrochemical CO2 reduction reaction (CO2RR) to achieve a sustainable solar-power-based economy is the development of high-performance electrocatalysts. The development process relies heavily on trial and error methods due to poor mechanistic understanding of the reaction. Demonstrated here is that ionic liquids (ILs) can be employed as a chemical trapping agent to probe CO2RR mechanistic pathways. This method is implemented by introducing a small amount of an IL ([BMIm][NTf2]) to a copper foam catalyst, on which a wide range of CO2RR products, including formate, CO, alcohols, and hydrocarbons, can be produced. The IL can selectively suppress the formation of ethylene, ethanol and n-propanol while having little impact on others. Thus, reaction networks leading to various products can be disentangled. The results shed new light on the mechanistic understanding of the CO2RR, and provide guidelines for modulating the CO2RR properties. Chemical trapping using an IL adds to the toolbox to deduce the mechanistic understanding of electrocatalysis and could be applied to other reactions as well.
- Etzold, Bastian J. M.,Hermans, Yannick,Hofmann, Jan P.,Katsounaros, Ioannis,Reichert, Andreas M.,Schmatz, Patrick,Shen, Liu-Liu,Straub, Sascha-Dominic,Zhang, Gui-Rong
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supporting information
p. 18095 - 18102
(2020/09/09)
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- Various metal organic frameworks combined with imidazolium, quinolinum and benzothiazolium ionic liquids for removal of three antibiotics from water
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In this research, imidazolium, quinolinum and benzothiazolium based ionic liquids (ILs) were immobilized on a metal organic framework (MOF) by solvent impregnation or capillary action. The synthesized IL@MOF composite materials were characterized by FTIR, XRD, SEM and TGA methods and then applied in removal of tetracyclines (TCs) from aqueous samples. The presence of ionic liquids significantly improved the adsorption efficiency of the metal organic framework, with 82% or higher removal percentage was obtained for the three target TCs while the pristine MOFs adsorption efficiency was below 50%. This could be attributed to the ability of ILs to make complex interaction with target drugs via multiple intermolecular forces. Experimental results revealed the effects of three significant factors including pH, temperature and solid-liquid ratio, and optimum adsorption efficiency could be achieved at pH 8 and 30 °C when solid-liquid ratio = 1:2 was adopted. The adsorption kinetics was properly fitted with pseudo-second order model and Redlich-Peterson model could be used to describe the adsorption isotherm for three antibiotics; moreover, the adsorption was an endothermic and spontaneous process in nature. Finally, the adsorbed TCs could be desorbed efficiently and the performance of the IL@MOF sorbent was further verified by actual water samples.
- Yohannes, Alula,Li, Jing,Yao, Shun
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- Ionic Liquids Catalyzed Friedel–Crafts Alkylation of Substituted Benzenes with CCl4 Toward Trichloromethylarenes
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Abstract: An ionic liquid catalyzed Friedel–Crafts alkylation reaction of substituted benzenes with CCl4 was developed. The reaction proceeded efficiently under mild conditions, gave corresponding trichloromethylarenes with diversity functional groups in moderate to good yields. The influence of Lewis acidity of ionic liquids on the conversion of the alkylation reaction has been investigated. Notably, the probable mechanism of this reaction has been proposed with the assistance of 27Al NMR spectroscopy. It was noteworthy that the predominance of [Al2Cl7]? species in EmimCl–AlCl3, N = 0.67 could be detected by 27Al NMR spectral analysis, and [AlCl4]? was generated at the beginning of reaction. Additionally, it was found that [AlCl4]? could be transformed into [Al2Cl7]? when the reaction finished. Some control experiments confirmed that the interaction between Lewis acidic species [Al2Cl7]? of the ionic liquid and CCl4 led to the change in speciation of aluminum during the alkylation reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Lyu, Xinyu,Wang, Wencheng,Sun, Yiqun,Zhao, Qian,Qiu, Tao
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p. 665 - 671
(2019/01/04)
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- Method for preparing alpha, alpha-dimethyl benzyl alcohol under dual catalyst and solvent-free conditions
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The present invention relates to a method for preparing alpha, alpha-dimethyl benzyl alcohol under dual catalyst and solvent-free conditions. The method comprises the following steps of 1) preparing an ionic liquid catalyst; 2) adding cumene, the ionic liquid catalyst and an inorganic salt catalyst into a reactor with a reflux device, introducing a certain amount of air into the reactor as an oxygen source, and enabling cumene to perform an oxidation reaction under a solvent-free condition; and 3) after the reaction is finished, performing standing, wherein after the material in the reactor islayered, the upper-layer material is a reaction product alpha-dimethyl benzyl alcohol and the lower-layer material is a mixed catalytic system formed by the ionic liquid catalyst and the inorganic salt catalyst; and 4) separating the upper-layer material to obtain the reaction product alpha-dimethyl benzyl alcohol. The method is a brand-new synthesis mechanism, is low in cost and is suitable forlarge-scale industrial production.
- -
-
Paragraph 0102; 0104; 0105
(2019/12/31)
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- Simultaneous determination of Brilliant Green and Crystal Violet dyes in fish and water samples with dispersive liquid-liquid micro-extraction using ionic liquid followed by zero crossing first derivative spectrophotometric analysis method
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In this study, dispersive liquid-liquid micro-extraction using ionic liquid (IL-DLLME) combined with zero crossing first derivative spectrophotometric method was applied to quantitative determination of triphenylmethane dyes in binary mixtures. The 1-methyl-3-octylimidazolium hexafluorophosphate [OMIM][PF6] ionic liquid was used to extract Brilliant Green (BG) and Crystal Violet(CV) dyes from aqueous solutions. The amplitude of the zero crossing first derivative spectra at 670 nm and 532 nm were selected for the determination of BG and CV, respectively. Significant factors influencing the extraction of BG and CV such as sample pH, kind of extraction solvent, amount of extractant, extraction and centrifuging times and ionic strength were investigated. Under the optimal conditions, the calibration curves for the simultaneous determination of both dyes were found to be linear in the range of 10–500 μg L?1 with detection limits (LODs) of 2.7 μg L?1 and 1.4 μg L?1 for BG and CV, respectively. The relative standard deviation (RSD%) for five replicate simultaneous determinations of BG and CV were 4.7% and 1.7%, respectively. Extraction efficiencies of the BG and CV dyes in the presence of interfering ions were also investigated. Sample preparation based on the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction combined with the IL-DLLME method and zero crossing first derivative spectrophotometric detection was applied for the simultaneous analysis of BG and CV in fish and water samples with quantitative recoveries.
- Sadeghi, Susan,Nasehi, Zohreh
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p. 134 - 142
(2018/05/22)
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- Deciphering the anthelmintic activity of benzimidazolium salts by experimental and in-silico studies
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Inspired from the facts that majority of the drug administrated in the form of salts and “poison is in the dose”; herein, we have synthesized and characterized 1-methyl-3-alkylbenzimidazolium and 1-methyl-3-alkylimidazolium derived ionic salts with varying N-alkyl chains and different anions. These ionic salts were evaluated for their vermicidal activity (VA) and cell viability test against the Pheretima posthuma and A549 cell lines (human alveolar basal epithelial cells), respectively. The morphological changes in the test organism were visualized by the Scanning Electron Spectroscopy (SEM) to get the mechanistic insight. Furthermore, results were compared with VA of 1-methyl-3-alkylimidazolium derivatives to establish their structure-activity-relationship (SAR) of the fused benzene ring in 1-methyl-3-alkylimidazolium. The current findings suggested that the activity of these salts depends on the nature of N-alkyl side-chain, anionic moieties, varying partial charge on quaternary nitrogen (due to different anions) lipophilicity and types of cationic core fused with imidazolium ring. These findings were complemented by the quantitative-structure-activity-relationship (QSAR), molecular docking approaches to unfold the features accountable for their activities and binding patterns of the ligand-receptor complex respectively. ADME/T assessment of the ionic salts shows that twelve compounds qualified the ADMET profiling test & encompasses the drug-likeness features.
- Ranjan, Prabodh,Athar, Mohd,Vijayakrishna, Kari,Meena, Lalit K.,Vasita, Rajesh,Jha, Prakash C.
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p. 156 - 168
(2018/07/25)
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- Infrared spectroscopic study of absorption and separation of CO using copper(i)-containing ionic liquids
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Absorption of carbon monoxide by copper(i)-containing ionic liquids, [Cnmim][CuX2] (Cnmim = 1-alkyl-3-methylimidazolium, n = 2, 4, 6, X = Cl, Br, I) has been investigated using in situ high pressure infrared spectroscopy. For each liquid, observation of a ν(CO) band in the region 2075-2090 cm-1 indicates the formation of copper(i) monocarbonyl complexes, assigned as [Cu(CO)X2]-. The rate of growth and equilibrium intensity of the ν(CO) absorption is dependent on applied CO pressure. Binding of CO is reversible such that complete desorption occurs rapidly on heating above 100 °C and the liquids are robust over multiple gas absorption/desorption cycles. For the series of [C6mim][CuX2] salts the CO absorption ability follows the order Cl ≥ Br> I. Selective absorption of CO from CO/H2 and CO/N2 gas mixtures is demonstrated by measuring the changes in headspace CO content upon absorption and desorption of gas. For [C6mim][CuCl2], a single absorb-vent-desorb cycle yields product gas containing ～95% CO starting from a 1:1 CO/N2 mixture, increasing to ～98% CO starting from a 4:1 CO/N2 mixture. This is particularly promising in view of the similar boiling points of CO and N2 that hinders their separation by cryogenic distillation.
- Repper, Stephen E.,Haynes, Anthony,Ditzel, Evert J.,Sunley, Glenn J.
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supporting information
p. 2821 - 2828
(2017/03/11)
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- Physicochemical properties of [Cnmim][TFA] (n = 2, 3, 4, 5, 6) ionic liquids
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A series of ionic liquids based on trifluoroacetic acid, namely, [Cnmim][TFA] (n = 2, 3, 4, 5, 6) (1-alkyl-3-methylimidazolium trifluoroacetate), were designed and synthesized. The density, surface tension and refractive index were measured in the temperature range of 293.15 to 343.15 ± 0.05 K, and some physicochemical properties of the ILs were calculated. Using the concept of molar surface Gibbs free energy, the traditional E?tv?s equation was improved into a modified E?tv?s equation, in which the intercept and the slope represented the molar surface enthalpy and the molar surface entropy, respectively, for [Cnmim][TFA] (n = 2, 3, 4, 5, 6). The thermal expansion coefficient (α) of [Cnmim][TFA] was calculated according to the interstitial model, and the order of magnitude of the calculated values was in good agreement with the corresponding experimental values. A new hypothesis was proposed, stating that the interstitial molar surface Gibbs free energy (gs) is not determined by the type of IL. From the refractive index and the molar surface Gibbs free energy, an equation to predict the surface tension of ILs was derived and the predicted values were highly correlated with the corresponding experimental values. Finally, a new polarity scale for ILs was developed, and the polarity order of the [Cnmim][TFA] (n = 2, 3, 4, 5, 6) ILs was estimated.
- Fang, Da-Wei,Zhang, Fang,Jia, Rui,Shan, Wei-jun,Xia, Li-xin,Yang, Jia-zhen
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p. 11616 - 11625
(2017/02/26)
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- Acid-induced chemoselective arylthiolations of electron-rich arenes in ionic liquids from sodium arylsulfinates: The reducibility of halide anions in [Hmim]Br
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An acid-induced protocol for the chemoselective arylthiolations of electron-rich arenes in ionic liquids from sodium arylsulfinates is introduced. The chemistry, in which [Hmim]Br (heaxylmethylimidazolium bromide) is used as both a solvent and a reducer, provides several advantages including odorless and simple operation, inexpensive reagents, recyclable solvents and gram-scale synthesis.
- Xu, Zhu-Bing,Lu, Guo-Ping,Cai, Chun
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p. 2804 - 2808
(2017/04/04)
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- Ionic liquid-mediated deoxydehydration reactions: Green synthetic process for bio-based adipic acid
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A novel recyclable Re-catalyzed deoxydehydration (DODH) reaction was developed with an ionic liquid (IL) as a reaction medium for an efficient synthesis of adipic acid (1), one of the commercially important dicarboxylic acids, from biomass galactaric acid. The carefully designed solubility of ILs allowed a homogeneous DODH reaction to produce muconate 3 in excellent yields, a key intermediate for 1. Use of the IL also enabled an efficient separation of the DODH product 3 from the reaction mixture by simple decantation. The recovered IL layer containing the expensive Re catalyst was reused up to four times, yielding 3 without much decrease in yields. The target compound 1 was also produced in an excellent yield with the catalytic hydrogenation of 3 followed by the acidic hydrolysis. Thus, the overall process for bio-based adipic acid would become much more cost-effective, eco-friendly, and industrially viable, which could be applied to various biomass conversions.
- Shin, Nara,Kwon, Sohyun,Moon, Sojeong,Hong, Chae Hwan,Kim, Young Gyu
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supporting information
p. 4758 - 4765
(2017/07/17)
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- Selenium ionic liquid and preparation method thereof
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The invention discloses a selenium ionic liquid and a preparation method thereof. The structural formula of the selenium ionic liquid is as shown in (I). The preparation method of the selenium ionic liquid comprises the following steps: taking a certain amount of N-methylimidazole, heating, using a constant-pressure dropping funnel to dropwise add a certain amount of bromo-nalkane, and then carrying out condensation backflow reaction operation to obtain an intermediate coarse product; washing the coarse product with an appropriate amount of mixed solution of ethyl acetate and acetonitrile at a mole ratio of 1:1-10:1, and drying to obtain a purified intermediate for standby use; dissolving the purified intermediate and KSeO2(OCH3) into CH3OH, mixing in room temperature, filtering, carrying out rotary evaporation to remove the solvent, and carrying out vacuum drying to obtain a target object ionic liquid. The ionic liquid disclosed by the invention is characterized in that a selenide is grafted onto the ionic liquid, and reactions at homogeneous phase and ordinary pressure can be realized, so that the volatilization of low-molecular selenide is overcome, and the reaction activity is improved.
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Paragraph 0047
(2017/08/24)
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- Halogen-free ionic liquids in naphtha desulfurization and their recovery
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Ionic liquids of the general formula C+A? where C+ represents an organic cation, specifically, but not limited to the imidazolium, pyridinium, isoquinolinium, ammonium types, which have aliphatic and aromatic substituents, while A? represents a carboxylate, aromatic and aliphatic anion. The ionic liquids are synthesized under conventional heating or microwave irradiation This invention is also related to the application of ionic liquids to remove sulfur compounds of naphthas through a liquid-liquid extraction and the recovery and reuse of ionic liquids by the application of heat, reduced pressure and washing with solvents.
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Page/Page column 5
(2018/01/20)
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- Inhibition of C(2)-H Activity on Alkylated Imidazolium Monocations and Dications upon Inclusion by Cucurbit[7]uril
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The inclusions of 1-methyl-3-alkylimidazolium cations (ICn+, n = 4, 6, and 8) and 3,3′-bis(3-(1-methylimidazolium))-1,n-alkane (DICn2+, n = 4, 6, and 8) in the macrocyclic cucurbit[7]uril result in a decrease (up to 25-fold) of the C(2)-H/D exchange rate constants and an increase in the C(2)-H pKa values (ΔpKa = 0.34 to 1.45). The alkyl chain lengths were found to play an important role in the extent of C(2)-H activity inhibition, upon complexation with cucurbit[7]uril.
- Li, Shengke,Wyman, Ian W.,Wang, Chunming,Wang, Yitao,Macartney, Donal H.,Wang, Ruibing
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p. 9494 - 9498
(2016/10/14)
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- Dual functionality of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids: Surfactants with catalytic function
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A series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6-C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst in an oxirane ring opening reaction in epoxidized fatty acid methyl esters (FAME). Their co-catalytic activities were determined and discussed as a function of their structure and surface properties. It was found that the co-catalytic properties, both conversion and selectivity, of alkylimidazolium hydrogen sulfate ionic liquids noticeably depended on the alkyl chain lengths, and in consequence their properties.
- Nowicki, Janusz,?uczak, Justyna,Stańczyk, Dorota
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p. 11591 - 11601
(2016/02/09)
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- Extraction of polysaccharides from Japanese cedar using phosphonate-derived polar ionic liquids having functional groups
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Extraction of polysaccharides from Japanese cedar using ionic liquids has been demonstrated. To this aim, eleven types of phosphonate ionic liquids have been synthesized, their properties investigated, and applied to biomass processing. All ionic liquids prepared display strong hydrogen-bonding characteristics of Kamlet-Taft parameters (β > 1.1) which enabled the effective extraction of polysaccharides from Japanese cedar. In particular, 15wt% of polysaccharides was extracted from Japanese cedar powder using 1-(3-methoxypropyl)-3-methyl-imidazolium ethyl ethylphosphonate. Since the ionic liquid is easily prepared using conventional reagents and might be applicable to large-scale reactions, it is expected that practical polysaccharide extraction using the ionic liquid might be possible from a wide variety of biomass resources.
- Fukaya, Yukinobu,Asai, Ryo-Ichi,Kadotani, Shiho,Nokami, Toshiki,Itoh, Toshiyuki
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p. 879 - 886
(2016/10/12)
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- Facile aromatic nucleophilic substitution (SNAr) reactions in ionic liquids: An electrophile-nucleophile dual activation by [Omim]Br for the reaction
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A facile aromatic nucleophilic substitution (SNAr) reaction in recyclable [Omim]Br under relatively mild conditions has been described. An electrophile-nucleophile dual activation by [Omim]Br is also discovered based on control experiments, 1H NMR and IR spectroscopies. This chemistry provides an efficient and metal-free approach for the generation of Caryl-X (XS, N, O) bonds, many of which are significant synthetic intermediates or drugs, making this methodology attractive to both synthetic and medicinal chemistry.
- Zhang, Xiao,Lu, Guo-Ping,Cai, Chun
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supporting information
p. 5580 - 5585
(2016/10/21)
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- Ultrafast dynamics in aromatic cation based ionic liquids: A femtosecond raman-induced kerr effect spectroscopic study
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We studied the ultrafast dynamics of 40 aromatic cation based ionic liquids (ILs) by means of femtosecond Ramaninduced Kerr effect spectroscopy. The low-frequency Kerr spectra (ca. 0.3700 cm1) of the ILs were obtained from the Kerr transients by Fourier-Transform deconvolution analysis. The low-frequency Kerr spectra in the frequency range less than 200 cm-1 coming mainly from the intermolecular vibrations for the ILs were discussed in terms of (i) anion dependence, (ii) imidazolium cations vs. pyridinium cations, (iii) alkyl group dependence, and (iv) effect of methylation in aromatic cations. Several liquid properties, such as density, viscosity, electrical conductivity, and surface tension, of the present sample ILs at 293K were also estimated in this study. We clarified that the aromatic cation based ILs show a different relation of the first moment of the low-frequency spectral band to the bulk liquid parameter, which is the square root of surface tension divided by liquid density, from aprotic molecular liquids. The slope of the first moment to the bulk parameter for the aromatic cation based ILs is gentler than that for aprotic molecular liquids.
- Shirota, Hideaki,Kakinuma, Shohei,Takahashi, Kotaro,Tago, Akito,Jeong, Hocheon,Fujisawa, Tomotsumi
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supporting information
p. 1106 - 1128
(2016/10/11)
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- Selective hydrogenation of phenol to cyclohexanone in water over PD@N-doped carbon derived from ionic-liquid precursors
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In this report, a kind of mesoporous N-doped carbon (CN-x) derived from N-containing ionic-liquid (IL) precursors were synthesized, and Pd@CN-x prepared by a simple ultrasound-assisted method showed higher catalytic activity for the selective hydrogenation of phenol and its derivatives under mild reaction conditions in water than commercial Pd@C and other common Pd heterogeneous catalysts. The catalytic activities of Pd@CN-x derived from different ILs were different, and further study into the influencing factors, including physical properties, N species of CN-x, and Pd status of Pd@CN-x, were performed. Being picky: N-Doped carbon (CN-x) derived from N-containing ionic-liquid precursors are used as Pd nanoparticle supports for the selective hydrogenation of phenol to cyclohexanone with high activity and selectivity under mild reaction conditions. The activities of the Pd@CN-x catalysts derived from a variety of ionic liquids are different, and studies on the physical properties, Pd status, and N species of the catalysts are performed.
- Xu, Xuan,Li, Haoran,Wang, Yong
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p. 3328 - 3332
(2015/04/16)
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- Volumetric Properties of Aqueous Ionic-Liquid Solutions at Different Temperatures
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Density measurements were carried out for aqueous solutions of the ionic liquids [BMIm]Cl, [BMIm]Br, [BMIm][BF4], [HMIm]Br, [OMIm]Br, [MMIm][MSO4], and [EMIm][ESO4] at T = (288.15-318.15) K. The measured densities were use
- Shekaari, Hemayat,Zafarani-Moattar, Mohammed Taghi,Kazempour, Amir,Ghasedi-Khajeh, Zakiyeh
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p. 1750 - 1755
(2015/06/25)
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- Special effect of ionic liquids on the extraction of flavonoid glycosides from Chrysanthemum morifolium Ramat by microwave assistance
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A microwave-assisted extraction approach based on ionic liquids of different chain lengths was successfully applied to the extraction of ten flavonoid glycosides from the flowering heads of Chrysanthemum morifolium Ramat. The pretreated sample was quantified by HPLC-ESI-MSn. The main components were identified as flavonoid glycosides, including three luteolin glycosides, three apigenin glycosides, three kaempferide glycosides, and one acacetin glycoside according to the characteristics of the corresponding CID mass spectrometric patterns. Eight ionic liquids from the imidazolium family with different chain lengths, namely, 1-alkyl-3-methylimidazolium bromide, [Cnmim]Br, (n = 2-16) were studied as extraction medium in water. Results indicated that alkyl chain length had an irregular impact on the extraction efficiency. Moreover, the best extraction efficiency was achieved by 1-dodecyl-3-methylimidazolium bromide aqueous solution ([C12mim]Br). Besides the alkyl chain length of the cations, other factors influencing extraction efficiency were systematically investigated, including concentration of the IL solutions, extraction time, matrix-to-solvent ratio and irradiation power.
- Zhou, Ying,Wu, Datong,Cai, Pengfei,Cheng, Guifang,Huang, Chaobiao,Pan, Yuanjiang
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p. 7683 - 7699
(2015/05/20)
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- Improvement of the Friedel-Crafts benzoylation by using bismuth trifluoromethanesulfonate in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid under microwave irradiation
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Bismuth trifluoromethanesulfonate (bismuth triflate) catalyzed the Friedel-Crafts benzoylation of activated aromatic compounds when dissolved in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]OTf) ionic liquid. Immobilization of bismuth triflate (5 mol %) in [BMIM]OTf allowed the synthesis of aryl ketones in good to excellent yields with short reaction times under microwave irradiation. This catalytic system was easily recovered and reused several times without any significant loss of the activity.
- Hoangtran, Phuong,Bichle Do, Ngoc,Ngocle, Thach
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p. 205 - 208
(2014/01/06)
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- Deep oxidative desulfurization of dibenzothiophene with molybdovanadophosphoric heteropolyacid-based catalysts
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Three hydrophobic Keggin-type heteropolyacid catalysts, [C 3H3N2(CH3)(C2H 4)]5PMo10V2O40 ([C 2mim]PMoV), [C3H3N2(CH 3)(C4H8)]5PMo10V 2O40 ([C4mim]PMoV) and [C3H 3N2(CH3)(C6H12)] 5PMo10V2O40 ([C6mim]PMoV) , were synthesized by reacting molybdovanadophosphoric acid with imidazolium bromides, and characterized by spectroscopic methods. Their use as catalysts in the extractive catalytic oxidative desulfurization process using hydrogen peroxide as the oxidant and acetonitrile as phase transfer agent was studied. The catalytic properties decreased in the order: [C6mim]PMoV > [C4mim]PMoV > [C2mim]PMoV. The main factors influencing the rate of removal of dibenzothiophene (DBT) were investigated, including reaction temperature, the amounts of catalyst, H2O2 and acetonitrile. Nearly 100 % sulfur removal rate was achieved under optimal conditions. The catalyst could be recycled six times with only a slight decrease in activity. A reaction mechanism for DBT oxidation is proposed, in which the Keggin anions first obtain active oxygen from H2O2, then the DBT is oxidized to dibenzothiophene sulfones.
- Zhuang, Jiangzhou,Hu, Bing,Tan, Junjun,Jin, Xiaoying
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p. 213 - 220
(2014/03/21)
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- Excess molar properties for binary systems of CnMIM-BF 4 ionic liquids with alkylamines in the temperature range (298.15 to 318.15) K. Experimental results and theoretical model calculations
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The experimental densities ρ and speeds of sound u for pure 1-hexyl-3-methylimidazolium tetrafluoroborate ([C6mim][BF 4]), 1-octyl-3-methylimidazolium tetrafluoroborate ([C 8mim][BF4]), butylamine (BA), and octylamine (OA) from (293.15 to 323.15) K and binary mixtures of the ionic liquids (ILs) with amines at (298.15, 308.15, and 318.15) K have been reported. The isentropic compressibilities, κS, Rao's molar sound functions, R, intermolecular free lengths, Lf, excess molar volumes, VmE, and excess isentropic compressibilities, κSE for binary mixtures were derived. The VmE and κSE of the binary mixtures are negative and decrease with increasing temperature, with the exception of VmE being positive for [C6mim][BF4] and [C8mim] [BF4] + OA in the high IL mole fraction region. The Prigogine-Flory-Patterson (PFP) theory has been applied to interpret the u and VmE data.
- Malek, Naved I.,Ijardar, Sushma P.,Oswal, Shantilal B.
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p. 540 - 553
(2014/04/03)
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- The efficient hydroxyalkylation of phenol with formaldehyde to bisphenol F over a thermoregulated phase-separable reaction system containing a water-soluble Bronsted acidic ionic liquid
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The efficient hydroxyalkylation of phenol with formaldehyde to bisphenol F over a thermoregulated phase-separable reaction system containing a water-soluble Bronsted acidic ionic liquid was studied. The reaction system containing the water-soluble IL showed thermoregulated biphasic behavior with change of the alkyl chain length of IL, temperature and water amount. Four types of imidazolium-, ammonium-, phosphonium- and pyridinium-based water-soluble ionic liquids with different anions of dihydrogen phosphate [H2PO4]-, acetate [CH3COO] - and hydrogen sulfate [HSO4]- were used as both Bronsted acidic catalysts and thermoregulated solvents. Among them, [C6MIM][HSO4] gave a high yield of 80.5% and a selectivity of 96.9% for bisphenol F, and the optimal reaction conditions were stirring speed 450 rpm, phenol-formaldehyde ratio 6:1, IL catalyst molar concentration 12.5%, reaction temperature 90 °C and reaction time 1 h. [C 6MIM][HSO4] could be recovered by simple decantation and could retain its original activity even after six recycling-uses [C nMIM][HSO4] with the alkyl chain length n = 6 found to be the most suitable for the synthesis of bisphenol F because of both the formation of a thermoregulated monophasic reaction system at 90 °C to enhance the reaction efficiency and as a thermoregulated phase-transition solvent to facilitate its recovery from the reaction system. the Partner Organisations 2014.
- Wang, Qing,Wu, Zhi Min,Li, Yongfei,Tan, Ying,Liu, Ning,Liu, Yuejin
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p. 33466 - 33473
(2014/08/18)
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- Highly efficient conductivity modulation of cinnamate-based light-responsive ionic liquids in aqueous solutions
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A new class of cinnamate-based light-responsive ionic liquids was synthesized and characterized, and these ionic liquids with longer alkyl chains showed a remarkable increase in ionic conductivity under UV light irradiation in aqueous solutions.
- Yang, Jie,Wang, Huiyong,Wang, Jianji,Zhang, Yue,Guo, Zhongjia
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supporting information
p. 14979 - 14982
(2014/12/11)
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- Conductometric study of ionic liquids in the presence of N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base in acetonitrile solutions at 298.15 K
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In recent years, Schiff bases and their metal complexes in the presence of ionic liquids (ILs) have been used in synthesis of various chemical compounds. To better understanding of ionic liquid influence on these processes, it is required to obtain information about the ion association behavior of the ionic liquids. Therefore, in this work, the molar conductivities of the ILs [RMIm]X (R= propyl, pentyl, and hexyl; X= Br- and Cl-) in different concentrations of N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base + acetonitrile solutions were determined at 298.15 K. The obtained conductivity data were analyzed by low concentration Chemical Model (lcCM) conductivity equation to calculate the limiting molar conductivities (Λ0) and ion association constants (KA). The results show that BPIE, alkyl chain length of cation, and anion type have effect on the ionic association process of the ILs. The Λ0 and KA values decrease as the Schiff base concentration, alkyl chain length of cation, and anion size increase in the solution. The association constants were also used to calculate the standard Gibbs energy (ΔG0A) of ion-pairing association. The resulted ΔG0A values are negative and become more negative as the alkyl chain length of the cation and the size of anion increase. The large negative values of the standard Gibbs energy obtained for [HMIm]Br indicates the more spontaneity and the more feasibility of the association process for this ionic liquid.
- Shekaari, Hemayat,Kazempour, Amir,Khoshalhan, Maryam
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p. 360 - 365
(2015/02/19)
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- Acidic-functionalized ionic liquid as an efficient, green, and metal-free catalyst for benzylation of sulfur, nitrogen, and carbon nucleophiles to benzylic alcohols
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A series of HSO4- functionalized ILs was synthesized and used as efficient, green, and metal-free catalysts for benzylation. Notably, the catalytic system has wide substrate scopes and the ionic liquid catalysts were applied to investigate three different types of nucleophiles to give the desired benzylation products with moderate to excellent yields.
- Chu, Xue-Qiang,Jiang, Ran,Fang, Yi,Gu, Zheng-Yang,Meng, Hua,Wang, Shun-Yi,Ji, Shun-Jun
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p. 1166 - 1174
(2013/02/25)
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- Densities, excess molar and partial molar volumes for water + 1-butyl- or, 1-hexyl- or, 1-octyl-3-methylimidazolium halide room temperature ionic liquids at T = (298.15 and 308.15) K
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Experimental densities for seven mixtures of water + 1-butyl-3- methylimidazolium iodide, [C4mim][I], + 1-hexyl-3-methylimidazolium chloride, [C6mim][Cl], + 1-hexyl-3-methylimidazolium bromide, [C 6mim][Br], + 1-hexyl-3-me
- Sastry, Nandhibatla V.,Vaghela, Nilesh M.,Macwan, Pradip M.
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