1124-64-7Relevant articles and documents
Synthesis and characterization of the iron-containing magnetic ionic liquids
Wang, Jieli,Yao, Hongwei,Nie, Yi,Zhang, Xiangping,Li, Jianwei
, p. 152 - 155 (2012)
Three species of room temperature magnetic ionic liquids (ILs) including 1-butyl-3-methylimidazolium tetrachloroferrate ([bmim]FeCl4), N-butylpyridium tetrachloroferrate ([bPy]FeCl4) and 1-butyl-1-methylpyrrolidium tetrachloroferrate ([bmP]FeCl4) were synthesized via two-step in this paper. The intermediates and magnetic ILs were characterized by ultimate analysis, 1H NMR, ESI-MS, FT-IR and Raman. In addition, the three magnetic ILs were quantitatively tested by magnetic property measurement system (superconducting quantum interference device), and the results indicated that they had similar magnetic susceptibilities and paramagnetic properties. This research expanded cationic types of magnetic ILs, and supplied fundamental data to application of magnetic ILs.
Decolorization of ionic liquids for spectroscopy
Earle, Martyn J.,Gordon, Charles M.,Plechkova, Natalia V.,Seddon, Kenneth R.,Welton, Thomas
, p. 758 - 764 (2007)
It has been widely recognized that although ionic liquids should be colorless, they are frequently not. Colored samples appear to be pure by most analytical techniques (e.g., NMR spectroscopy, mass spectrometry, HPLC, and ion chromatography), and there have been many attempts to identify the source of color in our own laboratories and others-after 20 years the best that can be said is that the impurities are at a very low level (probably parts per billion) with very high molar extinction coefficients. In this paper, we do not identify these impurities but describe a practical method for removing them for spectrochemical applications. We clearly note that the method is not "green", but we anticipate that it will only be applied to the small volumes of ionic liquids required for fundamental spectroscopic studies in academia but not in industrial processes.
Design and synthesis of basic ionic liquids for the esterification of triterpenic acids
Ressmann, Anna K.,Schneider, Maria,Gaertner, Peter,Weil, Matthias,Bica, Katharina
, p. 139 - 148 (2017)
Abstract: We present the design and synthesis of Br?nsted-basic ionic liquids and investigate their application in the microwave-assisted esterification of betulinic acid, aiming towards a benign and pyridine-free manufacturing process of the anti-HIV drug, bevirimat. Graphical abstract: [Figure not available: see fulltext.]
Does alkyl chain length really matter? Structure-property relationships in thermochemistry of ionic liquids
Verevkin, Sergey P.,Zaitsau, Dzmitry H.,Emel'Yanenko, Vladimir N.,Ralys, Ricardas V.,Yermalayeu, Andrei V.,Schick, Christoph
, p. 84 - 95 (2013)
DSC was used for determination of reaction enthalpies of synthesis of ionic liquids [Cnmim][Cl]. A combination of DSC with quantum chemical calculations presents an indirect way to study thermodynamics of ionic liquids. The indirect procedure for vaporization enthalpy was validated with the direct experimental measurements by using thermogravimetry. First-principles calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the CBS-QB3 and G3 (MP2) theory. Experimental DSC data for homologous series of alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were collected from the literature. We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies are linearly dependant on the alkyl chain length. The thermochemical properties of ILs generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization seem to be very close to those for molecular compounds.
Solvent-mediated photoinduced electron transfer in a pyridinium ionic liquid
Vieira, Rebecca C.,Falvey, Daniel E.
, p. 1552 - 1553 (2008)
The dynamics of electron transfer reactions in butyl pyridinium bis(trifluoromethanesulfonyl)imide (BuPyr-NTf2) and other solvents have been explored using laser flash photolysis. In these experiments, benzophenone (BP), duroquinone (DQ), and 9-cyanoanthracene (9CA) were used as excited-state acceptors, 1,4-diazabicyclo[2.2.2]octane and hexamethylbenzene were used as ground-state donors, and methyl viologen (MV2+) was used as a probe molecule. Analysis of kinetic and spectroscopic data from these experiments shows that electron transfer from photoreduced acceptors to the probe occurs via one or more solvent ions in cases where the acceptor anion radical has a reduction potential that is more negative than the solvent ions (BP?- and 9CA?- in BuPyr-NTf2). Mediated electron transfer was demonstrated to significantly enhance quantum efficiencies of photoinduced electron transfer in cases where back electron transfer would otherwise predominate. Copyright
Reaction kinetics in ionic liquids as studied by pulse radiolysis: Redox reactions in the solvents methyltributylammonium bis(trifluoromethylsulfonyl)imide and N-butylpyridinium tetrafluoroborate
Behar,Neta,Schultheisz, Carl
, p. 3139 - 3147 (2002)
Rate constants for several reduction and oxidation reactions were determined by pulse radiolysis in three ionic liquids and compared with rate constants in other solvents. Radiolysis of the ionic liquids methyltributylammonium bis(trifluoromethylsulfonyl)imide (R4NNTf2), N-butylpyridinium tetrafiuoroborate (BuPyBF4), and N-butyl-4-methylpyridinium hexafluorophosphate (BuPicPF6) leads to formation of solvated electrons and organic radicals. In R4NNTf2 the solvated electrons do not react rapidly with the solvent and were reacted with several solutes, including CCl4, benzophenone, and quinones. In the pyridinium ionic liquids the solvated electrons react with the pyridinium moiety to produce a pyridinyl radical, which, in turn, can transfer an electron to various acceptors. The rate constant for reduction of duroquinone by the benzophenone ketyl radical in R4NNTf2 (k = 2 × 107 L mol-1 s-1) is much lower than that measured in water (k = 2 × 109 L mol-1 s-1) due to the high viscosity of the ionic liquid. Rate constants for electron transfer from the solvent-derived butylpyridinyl radicals in BuPyBF4 and BuPicPF6 to several compounds (k of the order of 108 L mol-1 s-1) also are lower than those measured in water and in 2-PrOH but are significantly higher than the diffusion-controlled rate constants estimated from the viscosity, suggesting an electron hopping mechanism through solvent cations. Electron transfer between methyl viologen and quinones takes place 3 or 4 orders of magnitude more slowly in BuPyBF4 than in water or 2-PrOH and the direction of the electron transfer is solvent dependent. The driving force reverses direction on going from water to 2-PrOH and is intermediate in the ionic liquid. Radiolysis of ionic liquid solutions containing CCl4 and O2 leads to formation of CCl3O2. radicals, which oxidize chlorpromazine (ClPz) with rate constants near 1 × 107 L mol-1 s-1, i.e., much lower than in aqueous solutions and close to rate constants in alcohols. On the other hand, the experimental rate constants in the ionic liquids and in water are close to the respective diffusion-controlled limits while the values in alcohols are much slower than diffusion-controlled.
Photoelectrochemical Behavior of n-GaAs Electrodes in Ambient-Temperature Molten-Salt Electrolytes
Singh, P.,Rajeshwar, K.,DuBow, J.,Job, R.
, p. 4676 - 4681 (1980)
Photoelectrochemical (PEC) characterization of n-GaAs electrodes was carried out in room-temperature molten-salt electrolytes by using the aluminium chloride- butylpyridinium chloride (AlCl3-BPC) system as a representative example.The working potential limits for the above electrodes in the melts, containing varying ratios of AlCl3 and BPC, were established by cyclic voltammetry.Flat-band potential (Vfb) measurements on n-GaAs in the same melts enabled location of the semiconductor band edge positions relative to the melt stability windows.In electrolytes containing AlCl3 and BPC in the 1:1 molar ratio, the available range of potential was wide enough to probe the entire band-gap region.On the other hand, the potentials corresponding to the conduction band edges of n-GaAs were beyond the cathodic stability limit of both the 2:1 and 0.75:1 AlCl3-BPC compositions.The electrode dissolution behavior of illuminated n-GaAs electrodes was investigated by cyclic voltammetry in melts of varying composition containing no intentionally added electroactive species.The onset of photoanodic corrosion currents was significantly positive of the values observed in aqueous electrolytes.The redox behavior of ferrocene-ferricenium ion couple (Fe(Cp)2/Fe(Cp)2+) was studied by cyclic voltammetry on vitreous carbon electrodes in the 2:1, 0.75:1, and 1:1 AlCl3-BPC electrolytes.This couple was electrochemically reversible in the above melts.Photogenerated holes on n-GaAs electrodes were competitively captured by the electrochemically active ferrocene species in the 1:1 AlCl3-BPC electrolyte.This redox reaction occurred quite efficiently at the expense of the parasitic electrode dissolution process as judged by the constancy of photocurrents in a n-GaAs1:1 AlCl3-BPCFe(Cp)2/Fe(Cp)2+C PEC cell under short-circuit conditions for periods up to ca. 1 month.The uderpotentials developed for the photoanodic process on n-GaAs relative to the reversible (dark) thermodynamic values on vitreuos cabon were direct evidence for the sustained conversion of light energy to electrical energy.Rectifying behavior was observed on n-GaAs electrodes, with the reduction waves corresponding to the dark reduction of ferricenium chloride.The occurence of this process at potentials positive of Vfb indicated the mediation of surface states in the electron transfer process.Nonoptimized n-GaAs1:1Fe(Cp)2/Fe(Cp)2+C PEC cells typically showed open-circuit potentials of 680 mV, fill factors around 0.49, and a net optical-to-electrical conversion efficiency of ca. 1percent under illumination with a tungsten lamp at 40 mW/cm2.
Ionic liquids on the basis of 2,3,4,6,7,8,9,10-octahydropyrimido-[1,2-a] azepine (1,8-diazabicyclo[5.4.0]undec-7-ene)
Tolstikova,Shainyan
, p. 1068 - 1074 (2006)
New ionic liquids containing alkyl and polyfluoroalkyl substituents and various anions were synthesized from 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a] azepinium ion (1,8-diazabicyclo[5.4.0]undec-7-en-8-ium). Their NMR spectra and miscibility with water and organic solvents were studied. Pleiades Publishing, Inc., 2006.
Ionic liquids of chelated orthoborates as model ionic glassformers
Xu, Wu,Wang, Li-Min,Nieman, Ronald A.,Angell, C. Austen
, p. 11749 - 11756 (2003)
Ionic liquids based on various chelated orthoborate anions of different N-containing onium cations have been synthesized using an economic synthesis strategy. Most orthoborates do not crystallize. They are found to have much higher glass transition temperatures and room-temperature viscosities than those with perfluorinated anions such as TFSI-, BF4-, and CF3SO3- (Tf-), as predicted from anion polarizability arguments. The ambient conductivities of the new ionic liquids are low relative to those with perfluorinated anions. The transport properties all show that cohesion in these liquids increases, and ionic mobilities decrease, as anion size increases, implying that van der Waals interactions, not Coulomb interactions, have become the controlling influence. In view of their resistance to crystallization, the large range of temperature over which these liquids can be studied, their hydrophobic properties, and their high fragilities, these liquids may provide good model systems for fundamental liquid state investigations and interesting solvents for large-molecule dissolution.
Thermochemistry of the pyridinium- and pyrrolidinium-based ionic liquids
Verevkin, Sergey P.,Ralys, Ricardas V.,Emel'Yanenko, Vladimir N.,Zaitsau, Dzmitry H.,Schick, Christoph
, p. 353 - 358 (2013)
We applied DSC for the determination of enthalpies of synthesis reactions of pyridinium- and pyrrolidinium-based ionic liquids (ILs) from pyridine (or N-methyl-pyrrolidine) and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of enthalpies of the formation and vaporization enthalpies of ILs.
