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61.
62.
Novel Lewis-base ionic liquids replacing typical anions 总被引:1,自引:0,他引:1
Masahiro Yoshizawa-Fujita Katarina Johansson Douglas R. MacFarlane 《Tetrahedron letters》2006,47(16):2755-2758
We have synthesized two kinds of new Lewis-base ionic liquids (ILs); one is based on the relatively strong Lewis basic acetate anion, and the other is a salt composed of a mono-alkylated diamine such that the Lewis base site is incorporated in the cation. 1-Octyl-4-aza-1-azonia-bicyclo[2.2.2]octane bis(trifluoromethanesulfonyl)amide, [C8dabco]TFSA, and N-butyl-N-methylpyrrolidinium acetate, [p1,4]OAc, melted into fluid liquids at 26 and 81 °C, respectively. The thermal decomposition of [p1,4]OAc started at around 150 °C, whereas the thermal stability of [C8dabco]TFSA was almost equal to that of typical TFSA-based ILs in spite of the Lewis base site. This suggests that if the Lewis base site is incorporated into the cation the IL can maintain higher thermal stability. In addition, as a further result of the presence of the basic nitrogen, [C8dabco]TFSA can dissolve hydrated Cu(NO3)2 whereas the other TFSA-based ILs cannot. 相似文献
63.
George Stell 《Journal of statistical physics》1995,78(1-2):197-238
Recent experimental investigations of criticality and phase separation in ionic fluids have revealed behavior of great theoretical interest. In seeking to understand the experiments, some of which appear to exhibit argonlike criticality and some of which exhibit classical (mean-field) criticality, a convenient starting point is the restricted primitive model (RPM) of symmetrically charged hard spheres, all of equal diameter , each sphere bearing a positive or negative charge of magnitudeq. There is overall charge neutrality, so that the expected number densities of the anions and cations are equal,
+=
-. Studies of RPM charge-charge and density-density correlation functions indicate that the fluctuation-suppressing mechanism that yields mean-field critical behavior in nonionic systems with long-range interparticle potentials is not operative in the RPM. On the basis of plausible assumptions, Ising-like behavior is instead expected. The above work is summarized. New work of Zhang and the author is outlined, showing that when one loses the RPM symmetry (through, e.g., different valence, diameter, or dipole moment of anions and cations) a strong coupling between charge-charge and density-density correlation ensues. The way in which this can be expected to give rise to mean-field or mean-field-like behavior is noted. Other new observations concern the mean-field analogy found by Høye and the author between the parameter 2/(d–2) (d is the dimensionality) in that model and the monomer number in high polymers, with respect to the coexistence-curve shape dependence on those parameters. 相似文献
64.
Adi Wolfson Ivo F.J. Vankelecom Pierre A. Jacobs 《Journal of organometallic chemistry》2005,690(15):3558-3566
When ionic liquids (ILs) are employed as solvents for transition metal complex (TMC) catalyzed reductions, a second solvent can be added to increase the efficiency of the catalytic cycle and the solubility of the reactant in the IL phase. Two industrially relevant asymmetric hydrogenations, the enantioselective reductions of methyl 2-acetamidoacrylate with Rh-EtDuPHOS and methyl acetoacetate with Ru-BINAP, were performed in different catalytic systems including 1-butyl-3-methylimidazolium hexafluorophosphate/ tetrafluoroborate as ILs. Product separation and TMC recycling was performed by extracting the product from the reaction mixture. This can be accomplished by cooling the system, by adding an excess of the second solvent or by adding a third solvent. A high solubility of the second solvent in the IL catalytic phase favors the reaction activity, but can induce leaching of the IL and TMC. 相似文献
65.
Increased paraoxon detection by acetylcholinesterase inactivation with ionic liquid additives 总被引:1,自引:0,他引:1
This is the first study using ionic liquids (ILs) as additive in the aqueous solvent medium for detection of paraoxon by acetylcholinesterase inhibition method. A systematic comparison of various ILs with organic solvents has been made. The aqueous buffer solution containing ionic liquid ethylpyridinium hexafluorophosphate [EtPy]+[PF6]− has been found to give the best results. The inhibition kinetic follows the first order model. Ionic liquids modified aqueous solutions show the potential to provide a promising and effective medium in detection of paraoxon with acetylcholinesterase. 相似文献
66.
Pyridinium methanesulfonate (m.p. 185°C) and pyridinium p-toluenesulfonate (m.p. 121°C) were used as catalysts and media for the esterification of carboxylic acids with primary alcohols
to give the corresponding esters selectively in high yields. The high melting points of these pyridinium salts did not prevent
their application as ionic liquid medium for these reactions which were performed at 90°C. 相似文献
67.
68.
G. Hirankumar S. Selvasekarapandian M. S. Bhuvaneswari R. Baskaran M. Vijayakumar 《Journal of Solid State Electrochemistry》2006,10(4):193-197
Thick films of pure polyvinyl alcohol and polyvinyl alcohol doped with silver nitrate with different compositions have been
prepared by solution cast technique. The FT-IR spectrum confirms the complexation process. The conductivity of the pure polyvinyl
alcohol is of the order of 10−7 Sm−1 at 90 °C, and its value increases by two orders of magnitude when doped with 20 wt% of AgNO3. The activation energy, calculated from the Arrhenius plot for all compositions of the poly vinyl alcohol doped with silver
nitrate, is between 0.24 and 0.35 eV. The migration energy for the ion in polymer electrolyte has been calculated from the
modulus spectrum, and is in good agreement with the activation energy calculated from the Arrhenius plot. The modulus spectra
indicate the non-Debye nature of the material. 相似文献
69.
高分子固体电解质研究进展 总被引:6,自引:0,他引:6
高分子固体电解质具有质轻、粘弹性了、易成膜等许多无机电解质和有机溶剂电解质所不可比拟的优点,近年来得到了很大的发展,这种新型材料的应用主要集中开发全固态锂电池和锂离子电池。本文对SPE的电性能,离子传导特性以及提高SPE性能的途径等作了综述,并对其发展前景作了简要探讨。 相似文献
70.
硝基甲烷在离子液体BMImBF4中的电还原特性 总被引:1,自引:0,他引:1
采用循环伏安等测试方法, 以铂微盘电极为工作电极, 研究了硝基甲烷在离子液体1-正丁基-3-甲基咪唑四氟硼酸盐(BMImBF4)中的电化学行为, 并探讨了温度和扫描速率等因素对硝基甲烷电化学特性的影响. 实验结果表明, 硝基甲烷在离子液体BMImBF4中的还原反应是受扩散控制的不可逆过程. 估算了不同温度下硝基甲烷在离子液体BMImBF4中的扩散系数D, 进而求得它的扩散活化能Ea约为39.5 kJ·mol-1. 相似文献