- Ionic liquid-assisted synthesis of Pt nano thin films at toluene–water interface: Enhanced CO tolerance in methanol fuel cells and adsorptive removal of p-nitrophenol from water
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In this investigation, we report a one-pot method for the synthesis of Pt/ionic liquid nano thin films at organic-aqueous media at room temperature without using any harsh conditions. Synthesized Pt/ionic liquid thin films were characterized with common analytical techniques. Transmission electron microscope images confirmed the formation of spherical particles having a size distribution in the range of 4–12 nm. Ionic liquids have a key role in the control of better size distribution and prevent from agglomeration of nanostructures by preparing a shell around particles. These catalysts were applied for the reduction of toxic p-nitrophenol into non-toxic p-aminophenol and exhibited good catalytic activity. Also, they exhibit excellent CO tolerance in methanol oxidation process of fuel cells. This method provides a novel, rapid, low cost and economical alternative for the reduction of toxic organic pollutants in water and also to prepare high quality catalysts with low metal loading for methanol fuel cells. Pt/1-aminoethyl-3-methylimidazolium bromide exhibits better CO tolerance than Pt/1-methyl-3-octylimidazolium chloride and Pt/1-methyl-3-octylimidazolium tetrafluoroborate thin films.
- Sharfand, Saba Hamzepour,Hoseini, S. Jafar,Bahrami, Mehrangiz
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- Synthesis, Characterization, Surface Properties and Micellization Behaviour of Imidazolium-based Ionic Liquids
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Abstract: Ionic liquids (IL) have emerged as a prospective new material for a wide range of industrial applications, owing to their unique structures and properties. Hence, understanding the structure–property relationships of IL is very important for both fundamental and industrial applications. In this study, a series of imidazolium-based IL with different chain lengths, namely C8mimBF4, C10mimBF4 and C12mimBF4, were synthesized. Their molecular structures were confirmed by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) analysis. Thermal gravimetric analysis (TGA) revealed that the IL synthesized were thermally stable in the desired temperature range. Dynamic light scattering (DLS) results of IL was analyzed in order to understand the effect of alkyl length on micellar size. Conductivity and surface tension measurements were carried out to determine the adsorption and aggregation characteristics in aqueous solutions. The influences of temperature as well as alkyl chain length on viscosity were also investigated. Surface adsorption parameters such as surface excess, minimum area, effectiveness and efficiency were also determined from equilibrium surface tension data. A careful analysis of the thermodynamic aspects of air-ionic liquid aqueous systems reveals that free energies of adsorption are favoured over micellization for all systems.
- Pillai, Prathibha,Pal, Nilanjan,Mandal, Ajay
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- The conductivity of imidazolium-based ionic liquids from (-35 to 195) °c. A. variation of cations alkyl chain
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Data for the conductivity (κ) of the ionic liquids [emim][BF 4], [bmim][BF4], [hmim][BF4], and [omim][BF4] from (-35 to 195) °C are reported. The data can be well-fit with the Vogel-Fulcher-Tammann equation. Additionally, molar conductivities (Λ) were determined for the limited temperature range of (5 to 65) °C. Walden plots of these data indicate that the investigated compounds can be classified as "high-ionicity" ionic liquids. It is suspected that the large difference between the present κ values and some of the literature values is mainly due to the neglect of BF4-hydrolysis.
- Stoppa, Alexander,Zech, Oliver,Kunz, Werner,Buchner, Richard
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- Activation of hydrogen peroxide by the nitrate anion in micellar media
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We present the activation of hydrogen peroxide by micellar imidazolium nitratesviaH-bond formation in water, as shown by vibrational spectroscopy and supported by DFT calculations. Mechanistic insight into the interactions of the surfactant cation, the nitrate anion and H2O2is given. The micelles solubilise and epoxidise cyclooctene in the aqueous phase.
- Schmidt, Fabian,Zehner, Bastian,Kaposi, Marlene,Drees, Markus,Mink, János,Korth, Wolfgang,Jess, Andreas,Cokoja, Mirza
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- Physical and excess properties for binary mixtures of 1-methyl-3- octylimidazolium tetrafluoroborate, [Omim][BF4], ionic liquid with different alcohols
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In recent years, ionic liquids have increasingly gained importance as green solvents. The potential of these organic salts, which are moisture and air stable at room temperature, for new chemical processes and technologies is beginning to be recognized. R
- Arce, Alberto,Rodil, Eva,Soto, Ana
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- Antibacterial Activity of Imidazolium-Based Ionic Liquids Investigated by QSAR Modeling and Experimental Studies
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Predictive QSAR models for the inhibitors of B. subtilis and Ps. aeruginosa among imidazolium-based ionic liquids were developed using literary data. The regression QSAR models were created through Artificial Neural Network and k-nearest neighbor procedures. The classification QSAR models were constructed using WEKA-RF (random forest) method. The predictive ability of the models was tested by fivefold cross-validation; giving q2 = 0.77–0.92 for regression models and accuracy 83–88% for classification models. Twenty synthesized samples of 1,3-dialkylimidazolium ionic liquids with predictive value of activity level of antimicrobial potential were evaluated. For all asymmetric 1,3-dialkylimidazolium ionic liquids, only compounds containing at least one radical with alkyl chain length of 12 carbon atoms showed high antibacterial activity. However, the activity of symmetric 1,3-dialkylimidazolium salts was found to have opposite relationship with the length of aliphatic radical being maximum for compounds based on 1,3-dioctylimidazolium cation. The obtained experimental results suggested that the application of classification QSAR models is more accurate for the prediction of activity of new imidazolium-based ILs as potential antibacterials.
- Hodyna, Diana,Kovalishyn, Vasyl,Rogalsky, Sergiy,Blagodatnyi, Volodymyr,Petko, Kirill,Metelytsia, Larisa
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- Excess molar volumes and liquid-liquid equilibria of the ionic liquid 1-methyl-3-octyl-imidazolium tetrafluoroborate mixed with butan-1-ol and pentan-1-ol
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Experimental densities were measured for the system 1-methyl-3-octyl- imidazolium tetrafluoroborate [OMIM][BF4] + butan-1-ol, + pentan-1-ol at 298.15 K and ambient pressure using a vibrating tube densimeter, taking into account the influence of the viscosity correction. Excess molar volumes V E have been determined. VE is quite small and negative in the alcohol-rich range of the mixture composition and positive in the alcohol-poor range. LLE data of [OMIM][BF4] + pentan-1-ol have been measured using a laser light scattering cell for detecting cloud points at different compositions in the temperature range of 282-292 K. A miscibility gap with an upper critical solution temperature (UCST) of 292 K has been found.
- Heintz, Andreas,Klasen, Dagmar,Lehmann, Jochen K.,Wertz, Christiane
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- Tribromide Ionic Liquids: Probing the Charge Distribution of the Anion by XPS
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Abstract: We investigate a typical trihalide ionic liquid, 1-octyl-3-methylimidazolium tribromide, using X?ray photoelectron spectroscopy. The electronic environment of the anion is analyzed in detail. The Br 3d binding energies of the two components are both higher than that measured for 1-octyl-3-methylimidazolium bromide, due to the delocalization of the negative charge spreading over three atoms within the anion. The basicity of [Br3]– is estimated based upon N 1s binding energy. It is found similar to that of [BF4]–.
- Deng, Aimin,Men, Shuang,Rui, Mu
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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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- Interactions of CO2 with the homologous series of СnMIMBF4 ionic liquids studied in situ ATR-FTIR spectroscopy: spectral characteristics, thermodynamic parameters and their correlation
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In this work, in situ ATR-FTIR spectroscopy was used to study the interaction of CO2 and a series of 1-alkyl-3-methylimidazolium tetrafluoroborate СnMIMBF4 (n = 2, 4, 6, 8, 10) ionic liquids. A detailed analysis of the infrared spectra acquired from ionic liquids and sorbed СО2 was performed as ionic liquids with different the alkyl chain lengths were subjected to changing pressures of СО2 and temperature. With a longer alkyl chain length, an increase in the shift of the CH stretching vibrations bands of alkyl groups and BF stretching vibrations of BF4? anions is observed during CO2 sorption. This indicates the disaggregation of alkyl chains and anions. There is a correlation with the position of the wavenumber of the ν3 asymmetric stretching CO2 band and the length of the alkyl chain. It was found that some of the CO2 adsorbed by ionic liquids does not interact with the ionic liquid but is “free” in the bulk of the alkyl chains. For the first time, ATR-FTIR spectroscopy was used to determine the thermodynamic parameters of CO2 sorption in ionic liquids. It was demonstrated that the values of enthalpy and entropy obtained by analysis of the ATR-FTIR spectra are consistent the data obtained by other methods. A correlation was found between the enthalpy of sorption of CO2 and the wavenumber of the ν3 band. This opens up the possibility of using CO2 as an IR-sensitive probe molecule to characterize the acid-base properties of ionic liquids and determine the enthalpy of CO2 sorption.
- Adonin, Nikolai Y.,Kazarian, Sergei G.,Martyanov, Oleg N.,Nesterov, Nikolai S.,Prikhod'ko, Sergei A.,Shalygin, Anton S.
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- Ionic liquid-mediated solvothermal synthesis of 4,4′-methylenediphenyl diisocyanate (MDI): An efficient and environment-friendly process
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4,4′-Methylenediphenyl diisocyanate (4,4′-MDI) is an immensely important intermediate employed in the manufacturing of polyurethanes. Many synthetic routes have been developed over the decades for the synthesis of 4,4′-MDI compounds on a large scale; these compounds are highly toxic and hazardous in nature. In this study, an environment-friendly route is proposed for the synthesis of 4,4′-MDI using 4,4′-diaminodiphenylmethane and dimethyl carbonate (DMC) as starting materials, which are nontoxic in nature. The synthesis of ionic liquids (ILs) and their utilization in the decomposition reaction are systematically investigated. Imidazole-functionalized ionic liquids were prepared for the synthesis of 4,4′-MDI, and their thermal performances were evaluated by TGA. We found that in comparison with other imidazole-functionalized ionic liquids, 1-ethoxycarbonylmethyl-3-methylimidazolium tetrafluoroborate ([EAmim]BF4) exhibited preferable thermal activity for the decomposition of 4,4′-methylenediphenyl dimethylcarbamate (4,4′-MDC). Moreover, these ILs were more effective when they were combined with zinc as a catalyst, which enhanced the decomposition of MDC. Under optimal conditions, the yield of MDI compared to that of Zn(OAc)2-[EAmim]BF4 catalyst increased up to 96%. The mechanism of the enhanced performance of ionic liquids by catalytic activity of zinc acetate was also investigated.
- Duan,You,Liu,Ma,Zhou,Zhang,Zhang
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supporting information
p. 12243 - 12255
(2018/07/24)
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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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- Preparation process of dexmedetomidine hydrochloride for ICU (intensive care unit) sedation and analgesia
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The invention discloses a preparation process of dexmedetomidine hydrochloride for ICU (intensive care unit) sedation and analgesia. The preparation process includes the steps: first, stirring and reacting 1-(1-halogenated ethyl)-2, 3-dimethyl benzene and imidazole in ionic liquid under catalysis of ferric trichloride to obtain 4-[1-(2, 3-dimethyl phenyl) ethyl]-1H-imidazole; second, refluxing the 4-[1-(2, 3-dimethyl phenyl) ethyl]-1H-imidazole obtained in the first step and L-(+)-tartaric acid in absolute ethyl alcohol, and performing standing, cooling and suction filtration to obtain dexmedetomidine tartrate; third, stirring the dexmedetomidine tartrate in sodium hydroxide aqueous solution, extracting methylene dichloride, concentrating the solution, stirring the solution in saturated hydrochloric acid methanol solution to obtain the dexmedetomidine hydrochloride. The method is short in reaction time, high in yield, milder in condition and suitable for industrial popularization.
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Paragraph 0029; 0031; 0032
(2017/08/28)
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- Method for preparing dexmedetomidine hydrochloride for anesthesia and sedation during operation
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The invention discloses a method for preparing dexmedetomidine hydrochloride for anesthesia and sedation during an operation. The method comprises the following steps: (a) stirring and reacting 2,3-dimethyl styrene and imidazole in ionic liquid to obtain 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole in the presence of an iron salt; (b) reacting the 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole with L-(+)-tartaric acid, and performing suction filtering to obtain dexmedetomidine tartrate; (c) stirring the dexmedetomidine tartrate in an aqueous solution of sodium hydroxide, performing dichloromethane extraction and concentration, and stirring in a saturated hydrochloric acid methanol solution to obtain the dexmedetomidine hydrochloride. According to the method, the ionic liquid is used for alkylation reaction of the imidazole under catalysis of the iron salt, so that the reaction time is effectively shortened, and high yield is achieved; fewer steps are required, and the cost is lower; conditions in each step are mild, use of a large amount of lewis acid is avoided, and easiness for industrial production is achieved.
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Paragraph 0027; 0029
(2017/07/05)
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- Synthetic method of dexmedetomidine hydrochloride intermediate
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The invention discloses a synthetic method of a dexmedetomidine hydrochloride intermediate. The synthetic method comprises the following step: carrying out contact reaction on 1-(1-haloethyl)-2,3-dimethylbenzene and imidazole in ionic liquid in the presence of alkali and [1,1'-bis(diphenylphosphino) ferrocene] palladium dichloride to obtain the dexmedetomidine hydrochloride intermediate 4-[1-(2,3-dimethyl phenyl) ethyl]-1H-imidazole. The method is short in reaction time and high in yield, and has good selectivity for a target (S)-isomer.
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Paragraph 0029; 0031; 0032
(2017/08/28)
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- Comparative Investigation of the Ionicity of Aprotic and Protic Ionic Liquids in Molecular Solvents by using Conductometry and NMR Spectroscopy
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Electrical conductivity (σ), viscosity (η), and self-diffusion coefficient (D) measurements of binary mixtures of aprotic and protic imidazolium-based ionic liquids with water, dimethyl sulfoxide, and ethylene glycol were measured from 293.15 to 323.15 K. The temperature dependence study reveals typical Arrhenius behavior. The ionicities of aprotic ionic liquids were observed to be higher than those of protic ionic liquids in these solvents. The aprotic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, [bmIm][BF4], displays 100 % ionicity in both water and ethylene glycol. The protic ionic liquids in both water and ethylene glycol are classed as good ionic candidates, whereas in DMSO they are classed as having a poor ionic nature. The solvation dynamics of the ionic species of the ionic liquids are illustrated on the basis of the 1H NMR chemical shifts of the ionic liquids. The self-diffusion coefficients D of the cation and anion of [HmIm][CH3COO] in D2O and in [D6]DMSO are determined by using 1H nuclei with pulsed field gradient spin-echo NMR spectroscopy.
- Thawarkar, Sachin,Khupse, Nageshwar D.,Kumar, Anil
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p. 1006 - 1017
(2016/04/09)
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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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- A silver and water free metathesis reaction: A route to ionic liquids
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A versatile, cheaper, silver and water-free metathesis reaction was developed for imidazolium, phosphonium and pyrrolidinium based ionic liquids (ILs) associated with different anions such as dicyanamide, thiocyanate, tetrafluoroborate and bis(trifluoromethylsulfonyl)imide. This route, using the melt of amine chloride as a solvent and reagent, favours the ion exchange reaction using anion salts of Na or Li, yielding ionic liquids in high purity (≥99.5%) and high yields (≥90%). This route is particularly well adapted for water miscible ILs preparation.
- Srour, Hassan,Rouault, Helene,Santini, Catherine C.,Chauvin, Yves
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supporting information
p. 1341 - 1347
(2013/06/05)
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- Interaction between the ionic liquids 1-alkyl-3-methylimidazolium tetrafluoroborate and Pluronic P103 in aqueous solution: A DLS, SANS and NMR study
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The effect of three ionic liquids (ILs) 1-alkyl 3-methyl imidazlolium tetraflouroborates (Cnmim BF4 n = 4, 6, 8) on micellar solutions of an ethylene oxide-propylene oxide block copolymer (PEO-PPO-PEO), Pluronic P103 was examined from scattering and NMR techniques. The ILs alter the cloud point and micelle size dependant on their alkyl chain length and the results are discussed in terms of their behavior as cosolvent/cosurfactant. Cloud point data support the hydrogen bonding between the imidazolium cation and P103 while dynamic light scattering (DLS) and small angle neutron scattering (SANS) reveal that presence of ionic liquid is not conducive to the micelle formation of P103. The selective nuclear Overhauser effect (NOESY) indicates that the PPO block of the P103 interacts with the alkyl group of the C nmim+ cation by hydrophobic interaction. Through this kind of interactions, Cnmim BF4 and P103 can form mixed micelles. This result indicates that the presence of ILs hinders the micelle formation of P103 in solution and promotes P103 to orient at air/water interface.
- Parmar, A.,Bahadur, P.,Aswal, V. K.
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p. 137 - 143,7
(2012/12/11)
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- Efficient synthesis of 1,3-dialkylimidazolium-based ionic liquids: The modified continuous Radziszewski reaction in a microreactor setup
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By making use of a modified Radziszewski reaction, it is demonstrated that water-soluble 1,3-dialkylimidazolium-based ionic liquids can be produced in good yields (70-90%) and purities (>95%) starting from readily available, cost-effective monoalkylamines, glyoxal, formaldehyde, and mineral or organic acids. The homosubstituted 1,3-dialkylimidazolium salts feature high thermal stabilities similar to those of their heterosubstituted counterparts, and relatively low viscosities, thus fulfilling the requirements for solvent application. The effect of various parameters has been studied with the goal of improving yields for both the batchwise and continuous synthesis (making use of a microreactor setup), allowing for the production of a wide variety of ionic liquids and the introduction of functionalities. The applicability of these ionic liquids is demonstrated on the example of cellulose dissolution and the dehydration of fructose to 5-hydroxymethylfurfural.
- Zimmermann, Johannes,Ondruschka, Bernd,Stark, Annegret
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scheme or table
p. 1102 - 1109
(2011/04/24)
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- Synthesis of imidazolium and pyridinium-based ionic liquids and application of 1-alkyl-3-methylimidazolium salts as pre-catalysts for the benzoin condensation using solvent-free and microwave activation
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An efficient one-pot procedure for the synthesis of ionic liquids based on nitrogen-containing heterocycles, imidazolium or pyridinium under 'green chemistry' conditions has been described. Imidazolium salts and DBU have been found to catalyze efficiently the benzoin condensation giving good yields within very short reaction time using solvent-free microwave activation conditions.
- Aupoix, Audrey,Pégot, Bruce,Vo-Thanh, Giang
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scheme or table
p. 1352 - 1356
(2010/04/02)
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- Dimethyl carbonate synthesis catalyzed by DABCO-derived basic ionic liquids via transesterification of ethylene carbonate with methanol
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Easily prepared DABCO-derived (1,4-diazobicyclo[2.2.2]octane) basic ionic liquids were developed for an efficient synthesis of dimethyl carbonate (DMC) via the transesterification of ethylene carbonate (EC) with methanol. 1-Butyl-4-azo-1-azoniabicyclo[2.2.2]octane hydroxide ([C4DABCO]OH) exhibited high catalytic activity and 81% DMC yield together with 90% EC conversion was obtained under mild reaction conditions. Notably, the catalyst could be recycled for four times without loss of catalytic activity. Moreover, a possible mechanism was also discussed.
- Yang, Zhen-Zhen,He, Liang-Nian,Dou, Xiao-Yong,Chanfreau, Sébastien
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supporting information; experimental part
p. 2931 - 2934
(2010/06/16)
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- Lewis basic ionic liquids-catalyzed conversion of carbon dioxide to cyclic carbonates
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A series of easily prepared Lewis basic ionic liquids were developed for cyclic carbonate synthesis from epoxide and carbon dioxide at low pressure without utilization of any organic solvents or additives. Notably, quantitative yields together with excellent selectivity were attained when 1,8-diazabicyclo[5.4.0]undec-7-enium chloride ([HDBU]Cl) was used as a catalyst. Furthermore, the catalyst could be recycled over five times without appreciable loss of catalytic activity. The effects of the catalyst structure and various reaction parameters on the catalytic performance were investigated in detail. This protocol was found to be applicable to a variety of epoxides producing the corresponding cyclic carbonates in high yields and selectivity. Therefore, this solvent-free process thus represents an environmentally friendly example for the catalytic conversion of carbon dioxide into value-added chemicals by employing Lewis basic ionic liquids as catalyst. A possible catalytic cycle for the hydrogen bond-assisted ring-opening of epoxide and activation of carbon dioxide induced by the nucleophilic tertiary nitrogen of the ionic liquid was also proposed.
- Yang, Zhen-Zhen,He, Liang-Nian,Miao, Cheng-Xia,Chanfreau, Sebastien
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supporting information; experimental part
p. 2233 - 2240
(2010/11/05)
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- Lewis basic ionic liquids-catalyzed synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under solvent-free conditions
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A series of easily prepared Lewis basic ionic liquids were developed as recyclable and efficient catalysts for selective synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 without utilization of any organic solvent or additive. Notably, high conversion, chemo- and regio-selectivity were attained when 1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane bromide ([C4DABCO]Br) was used as the catalyst. Furthermore, the catalyst could be recycled over four times without appreciable loss of catalytic activity. The effects of the catalyst structure and various reaction parameters on the catalytic performance were investigated in detail. This protocol was found to be applicable to a variety of aziridines producing the corresponding 5-aryl-2-oxazolidinones in good yields and excellent regioselectivities. Therefore, this solvent-free process thus represents an environmentally friendly process for ionic liquid-catalyzed conversion of CO2 into value-added chemicals. A possible catalytic cycle for CO2 activation induced by nucleophilic tertiary nitrogen of the ionic liquid was proposed, based on studies using in situ FT-IR spectroscopy under CO2 pressure.
- Yang, Zhen-Zhen,He, Liang-Nian,Peng, Shi-Yong,Liu, An-Hua
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supporting information; experimental part
p. 1850 - 1854
(2011/02/23)
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- An efficient protocol for the preparation of pyridinium and imidazolium salts based on the Mitsunobu reaction
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We report herein that, in the absence of any nucleophilic counterions, tertiary nitrogen nucleophiles such as pyridines and imidazoles can be alkylated with alcohols, by simply using their ammonium form as the acidic component of the Mitsunobu reaction. This led to efficient preparation of ionic liquids under mild conditions, avoiding the usual anion exchange step.
- Petit, Sylvain,Azzouz, Rabah,Fruit, Corinne,Bischoff, Laurent,Marsais, Francis
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p. 3663 - 3665
(2008/09/20)
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- Preparation of second generation ionic liquids by efficient solvent-free alkylation of N-heterocycles with chloroalkanes
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Non-conventional techniques, such as microwave (MW) and power ultrasound (US) as well as combined MW/US irradiation, have been used to promote one-pot synthesis of second-generation ionic liquids (ILs), cutting down reaction times and improving yields. However, the use of chloroalkanes in the alkylation of N-heterocycles requires more drastic conditions if results are to match those obtained with more reactive alkyl halides. The present paper describes a series of MW- or MW/US-promoted IL preparations starting from chloroalkanes and classic heterocycles (1-methylimidazole, pyridine and 1-methylpyrrolidine). When reactions were carried out under conventional heating in an oil bath they required longer reaction times and gave poorer yields. 1H-NMR analysis and ion-exchange chromatography showed that the present solventless procedure afforded ILs of satisfactory purity. The observed high yields (usually 70-98% isolated), and short reaction times showed that a straightforward access to ILs can be also achieved with the use of alkyl chlorides, resulting in a considerable reduction of costs.
- Cravotto, Giancarlo,Gaudino, Emanuela Calcio,Boffa, Luisa,Leveque, Jean-Marc,Estager, Julien,Bonrath, Werner
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p. 149 - 156
(2008/09/17)
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- How to predict the physical properties of ionic liquids: A volume-based approach
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(Chemical Equation Presented) The molecular volume Vm (that is, the sum of the ionic volumes Vion of the constituent ions) of an ionic liquid (IL) in combination with an anion-dependent empirical relationship is all one needs to predict physical properties such as viscosity, conductivity, and density of [N(CN)2]-, [BF4]-, [PF6]-, and [N(SO2CF3) 2]- ionic liquids, including those which may as yet only exist on paper.
- Slattery, John M.,Daguenet, Corinne,Dyson, Paul J.,Schubert, Thomas J. S.,Krossing, Ingo
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p. 5384 - 5388
(2008/03/15)
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- A speedy one-pot synthesis of second-generation ionic liquids under ultrasound and/or microwave irradiation
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The present work describes an efficient one-pot synthesis of second-generation ionic liquids (ILs), combining in one step the Menshutkin reaction and anion metathesis. Working in a closed vessel under microwaves, or better still under simultaneous ultrasound and/or microwave irradiation, in a few minutes a series of ILs with 1-methylimidazole or pyridine cores were obtained in high yields (80?97% isolated). Under conventional heating, ILs could not be prepared in one pot in acceptable times and yields, whereas our protocol, carried out with commercially available equipment, was highly effective and reproducible. Moreover, 1H NMR analysis and ion-exchange chromatography showed that the present solventless procedure afforded satisfyingly pure ILs. CSIRO 2007.
- Cravotto, Giancarlo,Boffa, Luisa,L'Eveque, Jean-Marc,Estager, Julien,Draye, Micheline,Bonrath, Werner
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p. 946 - 950
(2008/03/17)
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- One-pot and solventless synthesis of ionic liquids under ultrasonic irradiation
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A novel method is described for the one-pot synthesis of various ionic liquids in a competitive time. By using ultrasonic irradiation, different families of nitrogen-bearing ionic liquids can be obtained in a solvent-free or in aqueous medium, which gives a greener touch to the overall process. Georg Thieme Verlag Stuttgart.
- Estager, Julien,Lévêque, Jean-Marc,Cravotto, Giancarlo,Boffa, Luisa,Bonrath, Werner,Draye, Micheline
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p. 2065 - 2068
(2008/02/10)
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- METHOD FOR THE PRODUCTION OF ONIUM SALTS WITH TETRAFLUOROBORATE ANION HAVING A REDUCED HALIDE CONTENT
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The invention relates to a method for producing onium salts with tetrafluoroborate anion by reacting an onium halide with an oxonium tetrafluoroborate, sulfonium tetrafluoroborate, or triphenylcarbonium tetrafluoroborate.
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Page/Page column 21
(2008/06/13)
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- The HF/BF3-catalysed reaction of substituted benzenes with carbon monoxide
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The HF/BF3-catalysed reactions of phenol and anisole as well as substituted benzenes with CO were investigated as possible routes to commercially important aldehydes. The results confirmed that HF and BF 3 are required in (at least) stoichiometric amounts for effective formylation with CO. With the aim of effecting truly catalytic reaction conditions, the formylation reactions were carried out in ionic liquids. It was shown that phenol is a good substrate for formylation in certain ionic liquids. Georg Thieme Verlag Stuttgart.
- Willemse, J. Alexander,Bezuidenhoudt, Barend C. B.,Holzapfel, Cedric W.
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p. 2543 - 2550
(2008/02/04)
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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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- A Novel and Eco-friendly Method for the Preparation of Ionic Liquids
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A novel and eco-friendly method is described for the direct preparation of a series of ionic liquids containing alkylimidazolium-based cations and hexafluorophosphate-based (or tetrafluoroborate-based) anions in a one-pot procedure by using ionic liquids themselves as solvents.
- Xu, Dan-Qian,Liu, Bao-You,Luo, Shu-Ping,Xu, Zhen-Yuan,Shen, Yin-Chu
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p. 2626 - 2628
(2007/10/03)
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- Single step preparation of ionic fluids
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Preparation of ionic liquids (I) involves alkylating an amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation of (I), with a halide (II) then replacing the sulfate anion by the anion of (I), the process is carried out without isolation of the intermediate. In the preparation of ionic liquids of formula (I) involves alkylating the amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation A with a halide of formula (II) then replacing the sulfate anion X by the anion Yn-, the process is carried out without isolation of the intermediate. (A)n.(Yn-) (I) RX (II) n = 1 or 2; Yn- = BF4, BCl4, PF6, SbF6, AsF6, AlCl4, ZnCl3, CuCl2, SO4, CO3, R'COO, R'SO3 or (R'SO2)2N; R' = 1-12C linear, branched or cyclic alkyl, 5-18C aryl, (5-18C) aryl-(1-6C) alkyl or (1-6C) alkyl-(5-18C) aryl (all optionally halo-substituted); A = NR1R2R3R or PR1R2R3R; or 1-(R)-3-(R1)-imidazolium, (R1)-substituted 1-(R)-pyridinium, 1-(R)-2-(R1)-pyrazolium or 1-(R)-1,3,5-triazolium (all optionally ring-substituted by one or more of 1-6C alkyl, 1-6C alkoxy, 1-6C aminoalkyl, 5-12C aryl or (5-12C) aryl-(1-6C) alkyl); R1-R3 = H; 1-20C linear, branched or cyclic alkyl; Het or Het-(1-6C) alkyl; or Ar or Ar-(1-6C) alkyl; R = 1-20C linear, branched or cyclic alkyl; Het-(1-6C) alkyl; or Ar-(1-6C) alkyl; Het = heteroaryl containing 3-8C and at least one of N, O and S (optionally substituted by one or more of 1-6C alkyl and halo); Ar = 5-12C aryl (optionally substituted by one or more of 1-6C alkyl and halo); and X = halogen.
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- An improved preparation of 1,3-dialkylimidazolium tetrafluoroborate ionic liquids using microwaves
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An efficient microwave protocol is described for the preparation of room temperature ionic liquids consisting of alkyl imidazolium cations bearing tetrafluoroborate as anions.
- Namboodiri, Vasudevan V,Varma, Rajender S
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p. 5381 - 5383
(2007/10/03)
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- Halogenide-free preparation of ionic fluids
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Preparation of ionic liquids (I) involves alkylating an amine, phosphine, imidazole, pyridine, triazole or pyrazole corresponding to the cation of (I) with a sulfate diester (II), then replacing the sulfate anion by the anion of (I). Preparation of ionic liquids of formula (I) involves alkylating the amine, phosphine, imidazole, pyridine, triazole or pyrazole, corresponding to the cation A, with a sulfate diester of formula (II), then replacing the sulfate anion R4SO4 or R5SO4 by the anion Yn-. (An).(Yn-) (I) R4SO2R5 (II) n = 1 or 2; Yn- = BF4, BCl4, PF6, SbF6, AsF6, AlCl4, ZnCl3, CuCl2, SO4, CO3, R'COO, R'SO3 or (R'SO2)2N; R' = 1-12C linear, branched or cyclic alkyl, 5-18C aryl, (5-18C) aryl-(1-6C) alkyl or (1-6C) alkyl-(5-18C) aryl (all optionally halo-substituted); A = NR1R2R3R or PR1R2R3R; or 1-(R)-3-(R1)-imidazolium, (R1)-substituted 1-(R)-pyridinium, 1-(R)-2-(R1)-pyrazolium or 1-(R)-1,3,5-triazolium (all optionally ring-substituted by one or more of 1-6C alkyl, 1-6C alkoxy, 1-6C aminoalkyl, 5-12C aryl or (5-12C) aryl-(1-6C) alkyl); R1-R3 = H; 1-20C linear, branched or cyclic alkyl; Het or Het-(1-6C) alkyl; or Ar or Ar-(1-6C) alkyl; R, R4, R5 = 1-24C linear, branched or cyclic alkyl; Het-(1-6C) alkyl; or Ar'-(1-6C) alkyl; Het = heteroaryl containing 3-8C and at least one of N, O and S (optionally substituted by one or more of 1-6C alkyl and halo); Ar = 5-12C aryl (optionally substituted by one or more of 1-6C alkyl and halo); and Ar' = 5-24C aryl (optionally substituted by one or more of 1-6C alkyl and halo).
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- The phase behaviour of 1-alkyl-3-methylimidazolium tetrafluoroborates; ionic liquids and ionic liquid crystals
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Air- and water-stable 1-alkyl-3-methylimidazolium tetrafluoroborate salts with the general formula [Cn-mim][BF4] (n = 0-18) have been prepared by metathesis from the corresponding chloride or bromide salts. The salts have been characterised by 1H NMR and IR spectroscopy, microanalysis, polarising optical microscopy and differential scanning calorimetry. Those with short alkyl chains (n = 2-10) are isotropic ionic liquids at room temperature and exhibit a wide liquid range, whereas the longer chain analogues are low melting mesomorphic crystalline solids which display an enantiotropic smectic A mesophase. The thermal range of the mesophase increases with increasing chain length and in the case of the longest chain salt prepared, [C18-mim][BF4], the mesophase range is ca. 150°C.
- Holbrey, John D.,Seddon, Kenneth R.
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p. 2133 - 2139
(2007/10/03)
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