- 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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Read Online
- 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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Read Online
- White-light emission from HMIMBF4-TiO4(A) colloidal hybrid electrolyte and surface modification of TiO2 using ionic liquid in hybrid optoelectronic devices
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White-light emission from the colloidal hybrid electrolyte 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4)-TiO2(A) is discussed herein. The HMIMBF4-TiO2(A) hybrid electrolyte showed an increase in the lifetime as compared to bare anatase TiO2 (TiO2(A)). The blue emission at 420 nm from HMIMBF4 is attributed to the π-π? transition of the imidazolium moiety, and strong green and yellow emissions at 517 and 568 nm, respectively, are due to defect emissions of TiO2 NPs. In the HMIMBF4-TiO2(A) colloidal hybrid electrolyte, the combination of blue emission from the ionic liquid and defect emission from TiO2 NPs produced intense white light. Fabricated HyLEDs showed enhanced device efficiency by the surface modification of rutile TiO2 (TiO2(R)) using HMIMBF4 ionic liquid. HMIMBF4, with a thickness of 250/850 nm, exhibited maximum current efficiency (ηc-cd A-1) of 322.22/361.53, power efficiency (ηp-lm W-1) of 6.2/7.1, external quantum efficiency (ηex-%) of 322.22/361.53 and luminance (ηL-cd m-2) of 70.14/1490.95. Spontaneously aligned dipole polarization within the ionic liquid HMIMBF4 layer reduced the electron injection barrier and led to enhanced device efficiencies.
- Thanikachalam, Venugopal,Seransenguttuvan, Balu,Jayabharathi, Jayaraman
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Read Online
- 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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Page/Page column 16-17
(2021/09/01)
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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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- 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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- 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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- 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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- Self-assembly and lower critical solution temperature properties of supramolecular block copolymer/ionic liquid complexes depending on the alkyl chain length of imidazolium rings
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We report the liquid crystalline (LC) assembly and lower critical solution temperature (LCST) properties of wedge-shaped block copolymer (BCP)/1-alkyl-3-methylimidazolium tetrafluoroborate ([CnMIM][BF4], n = 2, 4, 6) complexes (1–3) depending on the alkyl chain length of the ionic liquids (ILs). In contrast to the crystalline BCP, all of the ionic samples showed LC phases. 1 with [C2MIM][BF4] exhibited a hexagonal columnar phase, and 3 with [C6MIM][BF4] exhibited a gyroid phase. Interestingly, a temperature-dependent transformation from columnar phase to gyroid phase was revealed for 2 with [C4MIM][BF4]. The phase difference may be explained by the supramolecular shape change that was dependent on the alkyl chain length of the ILs. The LCST behavior was characterized using the differential scanning calorimetry, turbidity observations, and the X-ray diffraction techniques. Notably, the primary d-spacing began to decrease at the clouding temperature (Tc). 3 showed the highest Tc at 130 °C, which is greater than the temperature of the order-to-disorder transition. The results demonstrate that the subtle variation in the IL structure affects the morphological and LCST properties.
- Noh, Minjoo,Cho, Byoung-Ki
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p. 3587 - 3596
(2017/09/06)
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- Directed Phase Transfer of an FeII4L4 Cage and Encapsulated Cargo
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Supramolecular capsules can now be prepared with a wide range of volumes and geometries. Consequently, many of these capsules encapsulate guests selectively by size and shape, an important design feature for separations. To successfully address practical separations problems, however, a guest cannot simply be isolated from its environment; the molecular cargo must be removed to a separate physical space. Here we demonstrate that an FeII4L4 coordination cage 1 can transport a cargo spontaneously and quantitatively from water across a phase boundary and into an ionic liquid layer. This process is triggered by an anion exchange from 1[SO4] to 1[BF4]. Upon undergoing a second anion exchange, from 1[BF4] to 1[SO4], the cage, together with its encapsulated guest, can then be manipulated back into a water layer. Furthermore, we demonstrate the selective phase transfer of cationic cages to separate a mixture of two cages and their respective cargoes. We envisage that supramolecular technologies based upon these concepts could ultimately be employed to carry out separations of industrially relevant compounds.
- Grommet, Angela B.,Nitschke, Jonathan R.
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supporting information
p. 2176 - 2179
(2017/02/23)
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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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- Conductivities of binary mixtures of ionic liquids with polar solvents
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Data for the conductivity, κ, of selected binary mixtures of the ionic liquids [emim][BF4], [bmim][BF4], [bmim][PF 6], [brmm][DCA], and [hmim][BF4] with polar solvents (water, propylene carbonate, dimethyl-sulfoxide, methanol, dichloromethane) at 25 °C are reported. Additionally, mixture densities, p, were determined to convert κ into molar conductivity, A. The obtained results were fitted by appropriate interpolation formulas. Where possible, data were compared with information from the literature. Electrode polarization and sample purity, including [BF4-] hydrolysis, were considered as possible sources of errors in κ. The effect of viscosity on the accuracy of p and thus A was checked.
- Stoppa, Alexander,Hunger, Johannes,Buchner, Richard
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experimental part
p. 472 - 479
(2010/04/05)
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- A green and novel procedure for the preparation of ionic liquid
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A green and novel procedure is described for the preparation of a series of ionic liquid containing alkylimidazolium-based or N-alkylpyridinium-based cations and hexafluorophosphate-based or tetrafluoroborate-based anions in one-pot solvent-free conditions to give excellent yields with shortened time.
- Fang, Dong,Cheng, Jian,Gong, Kai,Shi, Qun-Rong,Zhou, Xin-Li,Liu, Zu-Liang
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p. 108 - 111
(2008/09/21)
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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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- 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 19
(2008/06/13)
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- An in-depth look at the effect of Lewis acid catalysts on Diels-Alder cycloadditions in ionic liquids
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The present work explores in detail the Diels-Alder reaction between cyclopentadiene and a series of dienophiles, performed in an innovative medium such as an ionic liquid. The potential activation of different Lewis acid catalysts and their load effect when used in combination with this solvent have been explored, in order to settle the improvement on rates and selectivities.
- Silvero, Guadalupe,Arévalo, María José,Bravo, José Luis,ávalos, Martín,Jiménez, José Luis,López, Ignacio
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p. 7105 - 7111
(2007/10/03)
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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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- Liquid Phase Behavior of Imidazolium-Based Ionic Liquids with Alcohols
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A systematic study of the impact of different characteristics of the ionic liquids (IL) and the alcohols on the liquid-liquid phase equilibrium of imidazolium-based IL and alcohols. Alcohol characteristics investigated include the effect of increasing the alkyl chain length of the alcohol (1-propanol vs. 1-butanol or 1-hexanol) and the effect of branching of the alcohol (1-butanol vs. 2-butanol or tert-butyl alcohol). An increase in the alkyl chain length of the alcohol resulted in an increase in the upper critical solution temperature (UCST), since the alcohol became more aliphatic and less able to interact with the IL through hydrogen-bonding, dipolar, and Coulombic forces. Increased branching of the alcohol did not affect the UCST but resulted in an increase in the solubility of the alcohol in the IL-rich phase, which correlates with increasing basicity of the alcohols. An increase in the length of one of the alkyl chains on the cation resulted in a decrease in the UCST, likely due to greater dispersion interactions between the alkyl chain on the cation and the chain of the alcohol. The UCST of the IL with alcohols decreased with increasing hydrogen bond strength. The effect of alkyl chain length on the cation and the choice of anion had significantly different effects on the mutual solubilities of IL with water than with alcohols.
- Crosthwaite, Jacob M.,Aki, Sudhir N. V. K.,Maginn, Edward J.,Brennecke, Joan F.
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p. 5113 - 5119
(2007/10/03)
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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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- Separation of olefins from paraffins using ionic liquid solutions
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Methods for separating olefins from non-olefins, such as parafins, including cycloparaffins, oxygenates and aromatics, are provided. The methods use metal salts to complex olefins, allowing the non-olefins to be separated by a variety of methods, including decantation and distillation. The metal salts are dissolved in ionic liquids, which tend to have virtually no vapor pressure, and which poorly solubilize the non-olefins. Accordingly, the non-olefins phase separate well, and can be distilled without carrying over any of the ionic liquid into the distillate. Preferred salts are Group IB salts, more preferably silver salts. A preferred silver salt is silver tetrafluoroborate. Preferred ionic liquids are those which form stable solutions or dispersions of the metal salts, and which do not dissolve the non-olefins. Further, if the olefins are subject to isomerization, the ionic liquid is preferably relatively non-acidic. The methods involve forming a solution of a suitable olefin-complexing salt in an appropriate ionic liquid. An olefin-containing mixture is contacted with the ionic liquid/salt solution, and the olefins are adsorbed. After the paraffins are removed, the olefins can be isolated by desorption. The olefin-containing mixture can be in the gas phase, or in the liquid phase. The flow of olefin-containing mixtures over/through the ionic liquid can be, for example, co-current, counter-current, or staged in stirred tanks. Countercurrent is preferred as it is the most efficient. The methods can be optimized using combinatorial chemistry.
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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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- 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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