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Suseeladevi Asha Kunduchi P. Vijayalakshmi Benny K. George 《International journal of quantum chemistry》2019,119(22):e26014
Electrochemical windows (ECWs) of the cyclic ammonium based ionic liquids formed by the combination of two common pyrrolidinium cations—N,N-butylmethyl pyrrolidinum(Pyr14) and N,N-hexylmethyl pyrrolidinium(Pyr16) and five anions—dicyanamide, trifluoroacetate, fluoromethane sulfonate, bis((trifluoromethylsulfonyl)imide, and bis(fluorosulfonyl)imide were investigated. The ECW of each ionic liquid was obtained from the oxidation and reduction potentials of these ionic liquids with respect to a Li+/Li reference electrode by using thermodynamic cycle method. The work reveals that the ECWs of these ionic liquids are solely decided by the HOMO energy of pairing anions. The ECWs were also computed using HOMO-LUMO method employing Møller-Plesset perturbation theory to the second order and M06L methods with a basis set of 6-31 + G(d, p). The ECW computed using M06L functional with an extended basis set of 6-311++G(d, p) showed better agreement with experimental values suggesting accurate computation of ECW is possible at lower computational cost. 相似文献
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Song and Mason equation of state (EOS) with a simple modification has been extended to modelling PVT properties of ionic liquids (ILs). The considered ILs are [C1mim][MeSO4], [C1mim][CH3OC2H5SO4], [C1mim][(CH3)2PO4], [C2mim][MeSO4], [C2mim][BF4], [C2mim][SCN], [C2eim][NTf2], [C4mim][C(CN)3], [C4mim][CF3SO3], [C4mim][SCN], [C5mim][NTf2], [C8mim][NTf2], [(C6H13)3P(C14H29)][Cl], [(C6H13)3P(C14H29)][NTf2], [(C6H13)3P(C14H29)][Ac], [C3mpyr][NTf2], [C4mpyr][NTf2] and [Py][C2H5OC2H4SO4]. Three temperature-dependent parameters in the proposed EOS have been scaled as functions of reduced temperature with the use of the law of corresponding states. It is shown that the knowledge of just critical temperature and critical density is sufficient to predict the PVT properties of these ILs. The overall average absolute deviation of calculated densities from literature values for 1347 data points of 18 ILs was found to be 0.58%. The predicted density of ILs from proposed EOS has been compared with those obtained by other literature work. Moreover, we indicate that the Zeno line regularity can well be predicted by proposed model for ILs. 相似文献
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二苯并噻吩及其氧化物与离子液体相互作用的理论研究 《燃料化学学报》2012,40(12):1444-1453
采用密度泛函理论方法比较了DBT/DBTO2和[BMIM]+[PF6]-/[BMIM]+[BF4]-的相互作用。对最稳定的[BMIM]+[PF6]-、[BMIM]+[PF6]--DBT、[BMIM]+[PF6]--DBTO2、[BMIM]+[BF4]-、[BMIM]+[BF4]--DBT、[BMIM]+[BF4]--DBTO2进行了NBO和AIM分析。结果表明,DBT和[BMIM]+[PF6]-/[BMIM]+[BF4]-中的咪唑环彼此相互平行,NBO和AIM分析表明它们之间发生了π-π相互作用。H1'和H9'形成的F…H氢键有利于π-π堆积作用的形成。DBTO2倾向于趋近C2-H2和甲基基团形成O…H相互作用;DBTO2优先吸附在[BMIM]+[PF6]-/[BMIM]+[BF4]-。在模拟油中,[BMIM]+[PF6]-和[BMIM]+[BF4]-离子液体对DBTO2的萃取能力大于DBT,其原因是可能是DBTO2具有较大的极性和O…H与F…H的氢键作用。 相似文献
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It is nowadays well-known that ionic liquids can dissolve cellulose. However, little systematic data has been published that shed light onto the influence of the ionic liquid structure on the dissolution of cellulose. We have conducted 1H NMR spectroscopy of ethanol in a large number of ionic liquids, and found an excellent correlation of the data obtained with the hydrogen acceptor properties (β-values). With this tool in hand, it is possible to distinguish between cellulose-dissolving and non-dissolving ionic liquids. A modulating effect of both, the anion of the non-dissolving ionic liquid and its cation was found in solubility studies with binary ionic liquid mixtures. The study was extended to other non-dissolving liquids, namely water and dimethylsulfoxide, and the effect of the cation was also investigated. 相似文献
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Matthew A. Addicoat Syou Fukuoka Alister J. Page Stephan Irle 《Journal of computational chemistry》2013,34(30):2591-2600
We present a novel method that enables accurate and efficient computational determination of conformationally flexible clusters, “Kick3” This method uses stochastically generated structures in combination with fast quantum mechanical methods. We demonstrate the power of this method by elucidating the structure of ionic liquid (IL) ([xMIM+][ clusters (x = E, B, D, n = 1–10,15). Dispersion‐corrected, third‐order self‐consistent‐charge density‐functional tight‐binding (DFTB3) is shown to be a computationally efficient, yet reliable approximation to density functional theory for predicting and understanding IL structure and stability. The presented approach, therefore, enables the accurate and efficient screening of ILs with high potential toward practical applications, without recourse to more expensive quantum chemical methods. © 2013 Wiley Periodicals, Inc. 相似文献
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《Journal of computational chemistry》2017,38(8):530-540
Ionic liquids (ILs) play a key role in many chemical applications. As regards the theoretical approach, ILs show added difficulties in calculations due to the composition of the ion pair and to the fact that they are liquids. Although density functional theory (DFT) can treat this kind of systems to predict physico–chemical properties, common versions of these methods fail to perform accurate predictions of geometries, interaction energies, dipole moments, and other properties related to the molecular structure. In these cases, dispersion and self‐interaction error (SIE) corrections need to be introduced to improve DFT calculations involving ILs. We show that the inclusion of dispersion is needed to obtain good geometries and accurate interaction energies. SIE needs to be corrected to describe the charges and dipoles in the ion pair correctly. The use of range–separated functionals allows us to obtain interaction energies close to the CCSD(T) level. © 2017 Wiley Periodicals, Inc. 相似文献
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Synthesis of chiral ionic liquids containing an imidazole nucleus and chiral centers on N-substituents is reported. [(2S,3S)-2,3-Dihydroxybutane-1,4-bis(3-butylimidazolium)]-[bis(trifluoromethanesulfonyl)amide]2 and [(4S,5S)-2-phenyl-1,3-dioxolane-4,5-bis(1-methylimidazolium)]-[bis(trifluoromethanesulfonyl)amide]2 induced enantioselectivity in the Michael addition of malonic esters to chalcones. 相似文献
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Ionic liquids have recently gained popularity in the scientific community owing to their special properties and characteristics. One of the reasons why ionic liquids have been termed “green solvents” is due to their negligible vapour pressure. Their use in electrochemical, biological and metal extraction applications is discussed. Wide research has been carried out for their use in batteries, solar panels, fuel cells, drug deliveries and biomass pretreatments. This work aims to consolidate the various findings from previous works in these areas. DOI 10.1002/tcr.201100036 相似文献
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4-硝基-1,3-丁二烯基胺分子的氢键效应 总被引:1,自引:0,他引:1
在从头计算的水平上, 利用杂化密度泛函理论研究了溶剂对4-硝基-1,3-丁二烯基胺分子的几何结构、分子内的电荷分布和电荷转移态的能量漂移的影响. 在四种极性溶剂中, 我们构造了包括氢键作用的超分子结构. 分别研究了由极化连续模型模拟的溶剂和溶质分子的长程相互作用, 溶剂和溶质分子的氢键作用, 以及溶剂和溶质分子的整体作用对分子结构和性质的影响. 研究结果表明氢键作用引起了溶质分子结构和性质的较大变化, 从而将明显地影响该类分子的非线性光学性质. 因此, 在模拟溶剂效应时需要考虑氢键作用. 相似文献
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Nitrogen-rich compounds involving the cyclo-pentazole anion (cyclo-N5−) have attracted extensive attention due to higher energy release and environmental friendliness than traditional high energy density materials (HEDMs). However, the synthesis of stable HEDMs with cyclo-N5− is still a challenge. In this study, the effect of nine solvents on the geometrical and electronic structures and solvation energies of Zn(N5)2, one of the recently synthesized nitrogen-rich compounds, was studied using the density functional theory and the polarized continuum model. The results indicated an increase in the stability of Zn(N5)2 in the solution phase compared to the vacuum phase, and the stability of Zn(N5)2 increases with increasing dielectric constants. The energy gap of frontier molecular orbitals and the absolute value of total energy in water are the largest, revealing that Zn(N5)2 is more stable in water than in other solvents. To understand the stabilization mechanism of Zn(N5)2 by water, further studies were performed with the natural bond orbital (NBO) analysis and the quantum theory of atoms in molecules (QTAIM) analysis using the explicit solvent model. The charge transfer and the hydrogen bonds are observed between Zn(N5)2 and water, which are beneficial to improvement of the stability of Zn(N5)2. This may indicate the solvents that have strong interactions with the cyclo-N5− candidate may improve the possibility of success of synthesis. 相似文献
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The role of binders is crucial to achieve high performance and long cycle lifes in next-generation electrodes for lithium batteries. Currently used binders in electrode configurations, such as poly(vinylidene difluoride) (PVDF) are inactive polymers that do not transport lithium ions themselves, causing restrictions for high-power applications. Thus, developing innovative binders with an affinity towards lithium mobility is important for both lithium-ion and lithium-air batteries. In this work, we present for the first time the use of PDADMA poly(ionic liquid)s with fluorinated anions (FSI, TFSI, BETI, and CFSO) as cathode binders in Li-ion and Li-air batteries. The high-voltage NMC 532 cathodes with fluorinated PDADMA binders showed improved cells performances as: capacity values, rate performance, and cycling stability in accelerating aging conditions dedicated for more environmental-friendly mobility applications. Especially, PDADMA-CFSO binder in cathodes shows a cell capacity increase of 26% at 5C (12 min charge), when compared to PVDF one. Moreover, the fluorinated PDADMA binders in cathode improve the discharge capacities in Li–O2 cells, both with liquid and solid gel polymer electrolytes. Impressively, the Coulombic efficiency improves by 146% and the cycling capacity by 70% in solid-state Li–O2 cells using PDADMA-CFSO binder in the cathode, instead of common lithiated Nafion. All in all, the proposed fluorinated PDADMA Poly(ionic liquid)s can be a highly competitive alternative to conventional binders used nowadays in Li-ion and Li-air batteries. 相似文献
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Applications of ionic liquids in electrochemical sensors 总被引:2,自引:0,他引:2
Ionic liquids (ILs) are molten salts with the melting point close to or below room temperature. They are composed of two asymmetrical ions of opposite charges that only loosely fit together (usually bulky organic cations and smaller anions). The good solvating properties, high conductivity, non-volatility, low toxicity, large electrochemical window (i.e. the electrochemical potential range over which the electrolyte is neither reduced nor oxidized on electrodes) and good electrochemical stability, make ILs suitable for many applications. Recently, novel ion selective sensors, gas sensors and biosensors based on ILs have been developed. IL gels were found to have good biocompatibility with enzymes, proteins and even living cells. Besides a brief discussion of the properties of ILs and their general applications based on these properties, this review focuses on the application of ILs in electroanalytical sensors. 相似文献
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V. E. Titov A. P. Doherty A. M. Mishura V. G. Koshechko V. D. Pokhodenko 《Theoretical and Experimental Chemistry》2007,43(2):71-78
The effect of various factors (the nature of the medium and the electrode material, the electronic structure of the Freons,
etc.) on the electrochemical activation and dehalogenation of a series of Freons [F113 (CF2ClCFCl2), F13B1 (CF3Br), F114B2 (CF2BrCF2Br), and F113B2 (CFClBrCF2Br)] in various low-temperature ionic liquids (LTIL) [1-butyl-3-methylimidazolium, 1-butyl-1-methylpyrrolidinium, and trihexyltetradecylphosphonium
bis(trifluoromethylsulfonyl)imides and 1-butyl-3-methylimidazolium hexafluorophosphate, tetrafluoroborate, and trifluoroacetate]
at various electrodes (glassy carbon, Pt, Ag) was studied. It was established in particular that the investigated processes
are affected substantially by the electrical conductivity and viscosity of the medium. With decrease of the latter the peak
potential in the cyclic voltammetry of the electrochemical reduction of the Freons is shifted toward less negative values
while the current increases. It was found that a silver cathode has a specific effect on the electrochemical activation of
the Freons in the LTILs, and this may be due to the formation of complexes Ag⋯Hal⋯Rf between the Freons and silver atoms on the electrode surface, in which cleavage of the C—Hal bond is facilitated. Such processes
are compared with the processes realized in the traditional solvent dimethylformamide.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 43, No. 2, pp. 67–74, March–April, 2007. 相似文献