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Imidazolium Ionic Liquids (imidazolium + ionic_liquid)
Selected AbstractsChemInform Abstract: tert-Alcohol-Functionalized Imidazolium Ionic Liquid: Catalyst for Mild Nucleophilic Substitution Reactions at Room Temperature.CHEMINFORM, Issue 10 2010Sandip S. Shinde Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Transition-Metal-Free Synthesis of Perdeuterated Imidazolium Ionic Liquids by Alkylation and H/D ExchangeEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2008Ralf Giernoth Abstract Economic, transition-metal-free syntheses of partially or completely deuterated imidazolium ionic liquids (ILs) were developed. Double alkylation starting from imidazole afforded side-chain deuterated imidazolium ionic liquids, which subsequently were fully deuterated by H/D-exchange on the cation ring. Isotopic exchange was studied for a range of ionic liquids, solvents and bases. Here, the presence of small amounts of basic impurities was found to significantly affect the exchange behaviour.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] A Simple and Practical Method for the Preparation and Purity Determination of Halide-Free Imidazolium Ionic LiquidsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2006Claúdia Abstract The reaction of N -alkylimidazole with alkyl sulfonates at room temperature affords 1,3-dialkylimidazolium alkanesulfonates as crystalline solids in high yields. The alkanesulfonate anions can be easily substituted by a series of other anions [BF4, PF6, PF3(CF2CF3)3, CF3SO3 and N(CF3SO2)2] by simple reaction of anions, salts, or acids in water at room temperature. Extraction with dichloromethane, filtration through a short basic alumina column and solvent evaporation affords the desired ionic liquids in 80,95% yield. The purity (>99.4%) of these ionic liquids can be determined by 1H NMR spectra using the intensity of the 13C satellites of the imidazolium N -methyl group as internal standard. [source] Dissolution and Doping of Polyaniline Emeraldine Base in Imidazolium Ionic Liquids Investigated by Spectroscopic TechniquesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 5 2007Fabio Rodrigues Abstract Polyaniline is a model molecular system in the study of conductive polymers. Ionic liquids, on the other hand, are becoming more and more a very convenient alternative for conventional organic solvents. The dissolution of polyaniline-emeraldine base (PANI-EB) in imidazolium ILs leads to its doping, as indicated by optical and resonance Raman spectroscopies. In this study, it is proposed that the interaction of PANI-EB and imidazolium ILs involves the specific interaction of the quinoid moiety of the former with the imidazolium ring of the latter, an interpretation that is also based on N K -edge XANES measurements of neat PANI-EB, neat ILs, and of their solutions. [source] Grignard Reactions in Imidazolium Ionic Liquids.CHEMINFORM, Issue 43 2006Scott T. Handy Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Towards a Molecular Understanding of Cation,Anion Interactions,Probing the Electronic Structure of Imidazolium Ionic Liquids by NMR Spectroscopy, X-ray Photoelectron Spectroscopy and Theoretical CalculationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2010Till Cremer Abstract Ten [C8C1Im]+ (1-methyl-3-octylimidazolium)-based ionic liquids with anions Cl,, Br,, I,, [NO3],, [BF4],, [TfO],, [PF6],, [Tf2N],, [Pf2N],, and [FAP], (TfO=trifluoromethylsulfonate, Tf2N=bis(trifluoromethylsulfonyl)imide, Pf2N=bis(pentafluoroethylsulfonyl)imide, FAP=tris(pentafluoroethyl)trifluorophosphate) and two [C8C1C1Im]+ (1,2-dimethyl-3-octylimidazolium)-based ionic liquids with anions Br, and [Tf2N], were investigated by using X-ray photoelectron spectroscopy (XPS), NMR spectroscopy and theoretical calculations. While 1H,NMR spectroscopy is found to probe very specifically the strongest hydrogen-bond interaction between the hydrogen attached to the C2 position and the anion, a comparative XPS study provides first direct experimental evidence for cation,anion charge-transfer phenomena in ionic liquids as a function of the ionic liquid's anion. These charge-transfer effects are found to be surprisingly similar for [C8C1Im]+ and [C8C1C1Im]+ salts of the same anion, which in combination with theoretical calculations leads to the conclusion that hydrogen bonding and charge transfer occur independently from each other, but are both more pronounced for small and more strongly coordinating anions, and are greatly reduced in the case of large and weakly coordinating anions. [source] Chain transfer to ionic liquid in an anionic polymerization of methyl methacrylateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2007Tadeusz Biedro When methyl methacrylate is polymerized with alkyllithium as initiator in imidazolium ionic liquids, low molecular weight polymers are formed in high yield. The head-groups are, however, not those alkyl groups that are present in alkyllithium, but predominantly those that are originally present at 1-position in imidazolium cation indicating extensive chain transfer to imidazolium ionic liquid. [source] Transition-Metal-Free Synthesis of Perdeuterated Imidazolium Ionic Liquids by Alkylation and H/D ExchangeEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2008Ralf Giernoth Abstract Economic, transition-metal-free syntheses of partially or completely deuterated imidazolium ionic liquids (ILs) were developed. Double alkylation starting from imidazole afforded side-chain deuterated imidazolium ionic liquids, which subsequently were fully deuterated by H/D-exchange on the cation ring. Isotopic exchange was studied for a range of ionic liquids, solvents and bases. Here, the presence of small amounts of basic impurities was found to significantly affect the exchange behaviour.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Reverse atom transfer radical polymerization of MMA via immobilized catalysts in imidazolium ionic liquidsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007Najun Li Abstract Reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) employing immobilized catalyst was approached at 50 and 60°C in [C8mim]PF6, and compared with the polymerization of MMA DMF as solvent. Other ionic liquids, [C6mim]BF4, [C8mim]BF4, and [C12mim]BF4, were used as solvents to perform the RATRP of MMA. By comparison, we found that the [C8mim]PF6 was the best solvent in this immobilized catalyst system and the polymerization was best controlled. In addition, the immobilized catalyst spherules can easily separate from the reaction mixture, which avoids the prevalent problem of the catalyst residual in RATRP and also gives us a possibility to recycle the catalyst system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3915,3919, 2007 [source] Collision-induced dissociation of sulfur-containing imidazolium ionic liquidsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2008Alain Lesimple Abstract A number of 1,2-dimethylimidazole ionic liquids substituted on NII with alkyl chains of varying lengths terminated with sulfur-containing groups were investigated by electrospray high-resolution tandem Fourier-transform mass spectrometry. Fragmentation pathways are strongly dependent on the oxidation state of the sulfur and the alkyl chain length. The dissociations detected are rationalized by deuterium labeling, comparisons between homologous compounds and accurate mass data. Several homolytic processes are reported, leading to distonic ions and loss of hydrogen, methyl and other free radicals. Copyright © 2007 John Wiley & Sons, Ltd. [source] Global phase behavior of imidazolium ionic liquids and compressed 1,1,1,2-tetrafluoroethane (R-134a)AICHE JOURNAL, Issue 2 2009Wei Ren Abstract Novel processes involving ionic liquids with refrigerant gases have recently been developed. Here, the complete global phase behavior has been measured for the refrigerant gas, 1,1,1,2-tetrafluoroethane (R-134a) and 1- n -alkyl-3-methyl-imidazolium ionic liquids with the anions hexafluorophosphate [PF6], tetrafluoroborate [BF4] and bis(trifluoromethylsulfonyl)imide [Tf2N] from ,0°C to 105°C and to 33 MPa. All of the systems studied were Type V from the classification scheme of Scott-van Konynenburg with regions of vapor-liquid equilibrium, miscible/critical regions, vapor-liquid-liquid equilibrium, and upper and lower critical endpoints (UCEP and LCEP). The effect of the alkyl chain length has been investigated, for ethyl-([EMIm]), n -butyl-([BMIm]), and n -hexyl-([HMIm]). With increasing chain length, the temperature of the lower critical end points increases and pressure at the mixture critical points decrease. With a common cation, the temperature of the LCEP increased and the mixture critical point pressures decreased in the order of [BF4], [PF6], and [Tf2N]. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source] Chain transfer to ionic liquid in an anionic polymerization of methyl methacrylateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2007Tadeusz Biedro When methyl methacrylate is polymerized with alkyllithium as initiator in imidazolium ionic liquids, low molecular weight polymers are formed in high yield. The head-groups are, however, not those alkyl groups that are present in alkyllithium, but predominantly those that are originally present at 1-position in imidazolium cation indicating extensive chain transfer to imidazolium ionic liquid. [source] Separation of ternary systems of hydrophilic ionic liquid with miscible organic compounds by RPLC with refractive index detectionJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6-7 2008Dongli Zhang Abstract A rapid and simple analytical method was developed for the simultaneous and quantitative determination and separation of hydrophilic imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium chloride, [C4mim]Cl; 1-hexyl-3-methylimidazolium chloride, [C6mim]Cl; 1-octyl-3-methylimidazolium chloride, [C8mim]Cl; 1-allyl-3-methylimidazolium chloride, [Amim]Cl; or 1-allyl-3-methylimidazolium bromide, [Amim]Br) with miscible ethyl acetate and EtOH and their mixtures using reverse phase liquid chromatography coupled with refractive index detection (RPLC,RI). The influence of 60 to 100% (volume percentage) methanol in the mobile phase on the IL systems ([C4mim]Cl, [C6mim]Cl, [C8mim]Cl, [Amim]Br, or [Amim]Cl)-ethyl acetate-EtOH was investigated. The optimum mobile phase for the system [C8mim]Cl-ethyl acetate-EtOH, [C4mim]Cl-ethyl acetate-EtOH, [Amim]Br-ethyl acetate-EtOH and [Amim]Cl-ethyl acetate-EtOH was methanol/water (60:40, v/v), and methanol/water (70:30, v/v) for [C6mim]Cl-ethyl acetate-EtOH. Under optimum mobile phase conditions for each system, the RSD of the retention time ranged from 0.02 to 0.04%, and the RSDs of the peak area percent ranged from 0.23 to 1.85%, which showed good reproducibility of the RPLC-RI method. The RPLC-RI method can determine IL, ethyl acetate, and EtOH simultaneously in 5 min, and the analytes, especially IL, can be eluted completely. The results show that the RPLC-RI method can be used to separate and determine ILs in mixtures with organic compounds simultaneously and quantitatively. [source] ChemInform Abstract: New Ionic Phosphite Ligands: Synthesis and Application in Asymmetric Rh-Catalyzed Hydrogenation.CHEMINFORM, Issue 34 2010S. E. Lyubimov Abstract The chiral phosphites are based on pyridinium and imidazolium ionic liquids and are coordinated in the monodendate mode to afford rhodium complexes. [source] | |||||||||||||