共查询到18条相似文献,搜索用时 93 毫秒
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在293.15~343.15 K温度范围内,用MYX-1密度计测定了系列离子液体 1-丁基-3-甲基咪唑硫酸氢盐[C4mim]HSO4 (1-butyl-3-methylimdazolium hydrosulfate)、1-己基-3-甲基咪唑硫酸氢盐[C6mim]HSO4 (1-hexyl-3-methylimdazolium hydrosulfate)、1-辛基-3-甲基咪唑硫酸氢盐[C8mim]HSO4 (1-octyl-3-methylimdazolium hydrosulfate)、1-癸基-3-甲基咪唑硫酸氢盐[C10mim]HSO4 (1-decyl-3-methylimdazolium hydrosulfate)的密度。利用不同温度下的密度值计算得出了离子液体的热膨胀系数及分子体积。利用Glasser经验方程计算了离子液体的标准熵和晶格能,并进一步对其热力学性质进行了讨论。 相似文献
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合成了新型离子液体1-烷基-3-甲基咪唑苯甲酰基三氟硼酸盐[Cnmim][BTB](n=4,6,8),并通过NMR、差热、热重等方法研究了其基础物化性质。 结果发现,3种离子液体的分解温度在200 ℃左右;随着阳离子碳链的增长,离子液体的粘度、熔点逐渐升高,并从亲水性变为疏水性。 尤其是疏水性的[C6mim][BTB]和[C8mim][BTB]在与水长时间的混合中表现出较好的稳定性,基本解决了四氟硼酸盐离子液体亲水性强、$BF^{-}_{4}$易水解的缺点,有望用于乏燃料后处理并提高临界安全。 相似文献
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离子液体1-丁基-3-三甲基硅咪唑六氟磷酸盐萃取细胞色素C 总被引:2,自引:0,他引:2
建立了疏水性离子液体1-丁基-3-三甲基硅咪唑六氟磷酸盐(BtmsimPF6)萃取细胞色素C(Cyt-c)的新方法.在萃取条件为pH 1.0,Cyt-c溶液体积3 mL,BtmsimPF6体积400 μL,萃取时间30 min时,5 mg/L Cyt-c的萃取效率为85%.萃取机理研究表明:在酸性条件下,Cyt-c发生构型转变,肽链伸展,使疏水性基团外露,增加了Cyt-c在疏水性离子液体中的溶解性;同时,当pH<2.0时,血红素基团中的Fe与Met-80的配位断裂,空出第六个配位空间,离子液体咪唑阳离子进入到肽链孔穴与Fe发生配位,形成新的配位键,从而被萃取到离子液体中. 相似文献
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采用密度泛函理论(DFT)对离子液体1-乙胺基-3-甲基咪唑四氟硼酸盐([NH2e-mim][BF4])吸收CO_2的反应机理进行了研究.在B3LYP/6-311++G(d,p)计算水平下,对离子液体[NH2e-mim][BF4]的结构及与CO_2反应的中间体、过渡态和产物进行了全优化,获得了优化结构的构型参数、振动频率和热力学数据.利用自然键轨道(NBO)分析了离子液体[NH2e-mim][BF4]和CO_2的自然电荷布居.计算结果表明,通过阳离子[NH2e-mim]+自偶解离产生的阳离子[NH3e-mim]2+能与阴离子[BF4]-结合形成更强的离子键.根据反应吉布斯自由能变(ΔG0—)和焓变(ΔH0—)的计算结果,判断离子液体[NH2e-mim][BF4]吸收CO_2按理论摩尔比2∶1分步进行反应,吸收过程中质子的转移需克服52.51 k J/mol的能垒. 相似文献
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制备了四种四丁基氯化铵类深共融溶剂,包括四丁基氯化铵:丙酸[TBAC:2PA]、四丁基氯化铵:乙二醇[TBAC:2EG]、四丁基氯化铵:聚乙二醇[TBAC:2PEG]、四丁基氯化铵:苯乙酸[TBAC:2PAA].在288.15-338.15 K温度范围内,测定了它们的密度、电导率、动力粘度及折光率.讨论了温度对密度、电导率、动力粘度及折光率等性质的影响.通过经验方程估算了深共融溶剂的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数.利用Vogel-Fulcher-Tamman (VFT)方程和Arrhenius方程,将测量的电导率和动力粘度对温度拟合,得到了动力粘度和电导率随温度变化方程式.有关研究对深共融溶剂的工业化应用具有重要意义. 相似文献
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通过衰减全反射红外(ATR-IR)光谱、二维红外相关谱结合量子化学计算研究了1-乙基-3-甲基咪唑三氟甲基磺酸盐([emim][OTf])和水之间的氢键作用. 结果表明,在[emim][OTf]-水体系中,当水的浓度较低时(0.1< x(D2O)< 0.3),水分子的主要存在形式是包裹在离子液体中的没有缔合的单体. 水分子优先填充到[emim][OTf]的空隙中,并且与[emim][OTf]的阴离子形成“[OTf]-…HOH…[OTf]-”结构,水分子与[emim][OTf]的阳离子的相互作用位点是烷基氢而不是芳香氢;当水分子浓度较高时,水分子倾向于自身缔合形成小团簇结构,水分子与[emim][OTf]的阳离子的相互作用位点是芳香氢而不是烷基氢. 相似文献
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Rafał Kocia 《国际化学动力学杂志》2019,51(12):958-964
Radiation-induced processes in oxygenated ionic liquid (IL) methyltributylammonium bis[(trifluoromethyl)sulfonyl]imide ([MeBu3N][NTf2]) solutions containing p-terphenyl (TP) were investigated by the nanosecond pulse radiolysis with UV-vis detection. The transient absorption spectra generated in these solutions were assigned to radical anions (TP•−), radical cations (TP•+), and triplet excited states (3TP*). Saturation of [MeBu3N][NTf2] solutions with oxygen (O2) efficiently eliminates solvated electrons (esolv−); however, it does not decrease significantly the radiation chemical yield of TP•−, which are mainly formed in a reaction of TP with presolvated electrons (epresolv−). On the other hand, the lifetime of TP•− decreases significantly due to their reaction with O2. The TP•+ is formed in a reaction of electron-deficient centers of the IL (IL⊕) with TP. Their radiation chemical yield and lifetime are not affected by the presence of O2; however, they are decreased by the presence of triethylamine (TEA). The 3TP* are formed in a reaction of excited states of ionic liquid (IL*) with TP. The presence of O2 and TEA effectively eliminates 3TP* in the time domain >1 μs. 相似文献
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E. P. Grishina A. M. Pimenova L. M. Ramenskaya O. V. Kraeva 《Russian Journal of Electrochemistry》2008,44(11):1257-1262
The effect of a water impurity (1.8–10 wt %) on the conductivity of the ionic liquid-H2O binary system was studied in a wide temperature range. It was shown that the interaction between components is characteristic of this system, and the molar ratio of components 1: 1 is boundary between the structures of solution and melt. The basic kinetic features of electrochemical reduction of water of the BMImBr-H2O binary system were determined by voltammetry with linear potential sweep. The transfer coefficient for the cathodic process (α = 0.46) and H2O molecule diffusivities were determined depending on the water content ( $ D_{H_2 O} The effect of a water impurity (1.8–10 wt %) on the conductivity of the ionic liquid-H2O binary system was studied in a wide temperature range. It was shown that the interaction between components is characteristic
of this system, and the molar ratio of components 1: 1 is boundary between the structures of solution and melt. The basic
kinetic features of electrochemical reduction of water of the BMImBr-H2O binary system were determined by voltammetry with linear potential sweep. The transfer coefficient for the cathodic process
(α = 0.46) and H2O molecule diffusivities were determined depending on the water content ( = (0.2–1.3) × 10−10 cm2s−1).
Original Russian Text ? E.P. Grishina, A.M. Pimenova, L.M. Ramenskaya, O.V. Kraeva, 2008, published in Elektrokhimiya, 2008,
Vol. 44, No. 11, pp. 1352–1358. 相似文献
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季铵盐型离子液体中全氟烷基磺酰亚胺盐催化的芳烃硝化反应 总被引:1,自引:0,他引:1
全氟烷基磺酰亚胺盐与季铵型离子液体(Cu(N(C4F9SO2)2)2/[N4446][NTf2] 或 In(NTf2)3/[N4446][NTf2])组成的新催化体系,可以很好的催化芳香族化合物的硝化反应。以氯苯的硝化为例,用硝酸和醋酸酐混合物为硝化试剂,在2mol%的Cu(N(C4F9SO2)2)2或In(NTf2)3催化剂催化下,室温下反应10分钟,氯苯的转化率就可分别达到87.6% 和 90.6%,反应产物的邻/对位比为4.3和4.8。并且这种催化剂与离子液体组成的催化体系很容易被回收,并可以连续使用5次以上。 相似文献
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Dr. David Bengio Dr. Thomas Dumas Sylvie Arpigny Dr. Richard Husar Dr. Eric Mendes Dr. Pier Lorenzo Solari Dr. Michel L. Schlegel Dr. Daniel Schlegel Dr. Stéphane Pellet-Rostaing Prof. Philippe Moisy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(63):14385-14396
Separation processes based on room temperature ionic liquids (RTIL) and electrochemical refining are promising strategies for the recovery of lanthanides from primary ores and electronic waste. However, they require the speciation of dissolved elements to be known with accuracy. In the present study, Eu coordination and EuIII/EuII electrochemical behavior as a function of water content in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf2]) was investigated using UV–visible spectrophotometry, time-resolved laser fluorescence spectroscopy, electrochemistry, and X-ray absorption spectroscopy. In situ measurements were performed in spectroelectrochemical cells. Under anhydrous conditions, EuIII and EuII were complexed by NTf2, forming Eu−O and Eu−(N,O) bonds with the anion sulfoxide function and N atoms, respectively. This complexation resulted in a greater stability of EuII, and in quasi-reversible oxidation–reduction with an E0’ potential of 0.18 V versus the ferrocenium/ferrocene (Fc+/Fc) couple. Upon increasing water content, progressive incorporation of water in the EuIII coordination sphere occurred. This led to reversible oxidation–reduction reactions, but also to a decrease in stability of the +II oxidation state (E0’=−0.45 V vs. Fc+/Fc in RTIL containing 1300 mm water). 相似文献
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E. P. Grishina N. O. Kudryakova L. M. Ramenskaya Yu. A. Fadeeva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(4):724-729
The temperature dependences of specific and equivalent conductivities, viscosity, density, and crystallization temperature are determined for three 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C n MeIm] [Tf2N], n = 2, 3, 4) ionic liquids saturated with water vapor at room temperature. It is established that in the area of positive temperatures, the relationship between viscosity and conductivity obeys the fractional Walden rule with exponents of 0.97, 0.92, and 0.92 for ionic liquids with ethyl-, propyl-, butylradicals, respectively. The temperature dependences of conductivity and viscosity are approximated using the Vogel–Fulcher–Tammann equation (R2 > 0.999), and ideal glass transition temperatures T0 are calculated for the investigated liquids. The obtained values of T0 depend largely on the chosen range of temperatures. It is shown that [C2MeIm][Tf2N] occupies a separate position with regard to [C3MeIm][Tf2N] and [C4MeIm][Tf2N]. 相似文献