Quasi-solid-state dye-sensitized solar cell based on a polymer gel electrolyte with in situ synthesized ionic conductors

A polymer gel electrolyte with in situ synthesized Acac-Py-I₂ ionic conductors was prepared for fabricating a quasi-solid-state dye-sensitized solar cell (QS-DSSC). The in situ synthesized Acac-Py-I₂ ionic conductors show weaker influence on the liquid electrolyte absorbency of the polymer gel electrolyte than that of Acac-Py-I₂ ionic conductors dissolved in liquid electrolyte. Owing to the higher liquid electrolyte absorbency, the polymer gel electrolyte with in situ synthesized Acac-Py-I₂ ionic conductors shows higher ionic conductivity than that of polymer gel electrolyte with Acac-Py-I₂ ionic conductors absorbed from liquid electrolyte. QS-DSSC containing the polymer gel electrolyte with in situ synthesized Acac-Py-I₂ ionic conductors shows 3.815% energy conversion efficiency, which is 21.6% higher than that of QS-DSSC containing polymer gel electrolyte with Acac-Py-I₂ ionic conductors absorbed from liquid electrolyte.     

Thermodynamic modeling of CO2 solubility in ionic liquid with heterosegmented statistical associating fluid theory

Heterosegmented statistical associating fluid theory is used to represent the CO₂ solubility in ionic liquids. As in our previous work, ionic liquid molecule is divided into several groups representing the alkyls, cation head, and anion. The cation of ionic liquid is modeled as a chain molecule that consists of one spherical segment representing the cation head and groups of segments of different types representing different substituents (alkyls). The anion of ionic liquid is modeled as a spherical segment of different type. To account for the electrostatic/polar interaction between the cation and anion, the spherical segments representing cation head and anion each have one association site, which can only cross associate. Carbon dioxide is modeled as a molecule with three association sites, two sites of type O and one site of type C, where sites of the same type do not associate with each other. The parameters of CO₂ are obtained from the fitting of the density and the saturation vapor pressure of CO₂. For the CO₂-ionic liquid systems, cross association between site of type C in CO₂ and another association site in anion is allowed to occur to account for the Lewis acid–base interaction. The parameters for cross association interactions and the binary interaction parameters used to adjust the dispersive interactions between unlike segments are obtained from the fitting of the available CO₂ solubility in ionic liquids. The model is found to well represent the CO₂ solubility in the imidazolium ionic liquids from 283 to 415 K and up to 200 bar.     

Thiophene separation from aliphatic hydrocarbons using the 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid

The ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate has been tested as solvent for the separation of thiophene from aliphatic hydrocarbons. Liquid–liquid equilibrium data have been determined for ternary systems containing the ionic liquid, thiophene and C₆, C₇, C₁₂ or C₁₆ alkanes at T = 298.15 K. The performance of the ionic liquid as solvent in such systems has been evaluated. The experimental data were correlated using the NRTL and UNIQUAC equations, and the binary interaction parameters have been reported. The phase diagrams for the ternary mixtures including both the experimental and calculated tie-lines have been presented.     

Nano-Fe3O4–Supported,Hydrogensulfate Ionic Liquid–Catalyzed,One-Pot Synthesis of Polysubstituted Pyridines

Abstract

Anchoring 1-methyl-3-(triethoxysilylpropyl) imidazolium chloride onto silica-coated magnetic Fe₃O₄ particles afforded the corresponding supported ionic liquid. Exchanging the Cl^? anion by treating with H₂SO₄ gave Brønsted ionic liquid 1-methyl-3-(triethoxysilylpropyl) imidazolium hydrogensulfate. The synthesized catalyst was characterized by various techniques such as infrared, x-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and elemental analyses. The results indicated that the prepared catalyst had a nanostructure. The catalytic activity of the supported ionic liquid was examined in the synthesis of the polysubstituted pyridines by reaction of aromatic aldehydes with acetophenones and ammonium acetate in moderate to good yields under solvent-free conditions. The catalyst can be easily recovered by applying an external magnetic field and reused for at least seven runs without deterioration in catalytic activity.     

Studies on the properties of ionic liquid BMIInCl4

An ionic liquid (IL) was prepared by directly mixing InCl₃ and 1-methyl-3-butylimidazolium chloride(BMIC) with molar ratio 1:1 under dry argon atmosphere. The densities, and surface tension of pure IL were determined at temperature range of (278.15 to 343.15±0.1K). The properties for ionic liquid based on group III were discussed using Glasser’s theory. The standard entropy, the surface energy and the crystal energy of ionic liquid were calculated, respectively. The crystal energy of ionic liquid is much lower than ionic solid and this is the underlying reason for forming ionic liquid at room temperature. In addition, a new theoretical model of IL, that is interstice model, was applied to calculate the thermal expansion coefficient of BMIInCl₄. The order of magnitude for the thermal expansion coefficient, a, calculated by the theoretical model is in good agreement with experimental value. The result shows that there is much reasonableness for the interstice model of ionic liquid. __________ Translated from Chemical Journal of Chinese University, 2005, 26(10)(in Chinese)     

Simple one-step preparation of cerium trifluoride nanoparticles

Cerium trifluoride have great potential in material applications for luminescent materials, composite materials or ionic conductors especially in the form of nanoparticles and nanoobjects. In this work, nanoparticles of CeF₃ were prepared by simple one pot reaction of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF₆) with CeO₂ and by reaction of CeO₂ with KPF₆ in ionic liquid 1-butyl-3-methylimidazolium chloride (bmimCl). Prepared nanoparticles were analyzed by XRD and SEM analysis. Average diameter of prepared nanoparticles resulting from Sherrer formula is 12 nm. Nanoparticles did not form ordered agglomerates and could be used in the form of separate nanoparticles which are desired in some applications.     

Predictions of cation and anion effects on solubilities,selectivities and permeabilities for CO2 in ionic liquid using COSMO based activity coefficient model

The solubilities and selectivities for CO₂, N₂ and CH₄ in ionic liquid were predicted using a COSMO based activity coefficient model, COSMO-SAC method. The 1-alkyl-3-methylimidazolium cations were focused in this work. The anion species include tetrafluoroborate [BF₄], hexafluorophosphate [PF₆], triflate [OTf], dicyanamide [dca] and bis(trifluoromethane)-sulfonimide [Tf₂N]. The predicted results of the solubilities of CO₂ in the ionic liquids by COSMO-SAC method are in agreement with the experimental data within the averaged deviation of 0.0017 in mole fraction. The predicted results of selectivities for CO₂/N₂ and CO₂/CH₄ represent the effects of anion species qualitatively. Permeability through supported liquid membrane can be presented by solubility and diffusion coefficients in the liquid. The permeabilities of CO₂ through the ionic liquid membranes were also predicted by a solution-diffusion model with COSMO-SAC method. The predicted results of the CO₂ permeabilities through the ionic liquids represent the experimental data within the order of the permeabilities.     

Wacker oxidation of terminal olefins in a mixture of [bmim][BF4] and water

A simple and efficient PdCl₂/CuCl catalyzed oxidation of alkenes has been successfully developed using a mixture of water and the ionic liquid [bmim][BF₄] as solvent. Starting from various types of terminal olefins, the corresponding ketones have been prepared under mild reaction conditions and obtained in good to excellent yields after a simple extraction with diethyl ether. Furthermore, it was possible to recycle and reuse the ionic liquid and the catalytic system.     

水热条件下金红石纳米晶在离子液体[C12mim]Cl中的制备

在室温离子液体1-十二烷基-3-甲基氯化咪唑([C12mim]Cl)中,通过水热法制备了具有单晶结构的金红石纳米材料。采用X射线衍射、扫描电镜和透射电镜对样品进行了表征,结果显示所得样品为纯金红石相,形貌呈棒状。扫描电镜和透射电镜图样显示金红石纳米棒的直径约为15 nm,长度在10～100 nm之间。高分辨投射电镜图样显示金红石纳米棒为单晶结构,并沿c轴方向生长。实验结果表明离子液体[C12mim]Cl中的Cl-有利于金红石相生成,[C12mim]+起到了模板剂的作用并提高了金红石纳米棒的结晶度。     

Osmium catalyzed asymmetric dihydroxylation of methyl trans-cinnamate in ionic liquids, followed by supercritical CO2 product recovery

In this work, osmium-catalyzed asymmetric dihydroxylation (AD) of methyl trans-cinnamate was studied. Osmium and chiral ligand catalysts were immobilized in ionic liquid only, without any other reaction solvents, while the recovery of the product was performed by extraction with supercritical CO₂, and compared with results obtained by extractions with organic solvents such as hexane and diethyl ether. In supercritical CO₂ extraction experiments, optimal extraction pressure was found and ionic liquid chosen, so that the highest reaction yields coupled with lowest osmium content in the crude product can be achieved. Finally, recycle experiments of the same (ionic liquid + catalytic system) mixture were successfully conducted. Application of ionic liquids and supercritical CO₂ in osmium catalyzed AD allows for the isolation of the diol basically without contamination with osmium, in high yield and enantiomeric excess, and it makes possible the efficient reuse of ionic liquid solvent and the catalytic system.     

Ionic liquids accelerate access to N-substituted-1,8-naphthalimides

The synthesis of N-substituted-1,8-naphthalimides is accelerated in the presence of the room temperature ionic liquid [BMIM][NO₃]. Reaction times are reduced from 18 h in volatile organic compounds (VOCs) (PhCH₃, EtOH and THF) to 20 min in the ionic liquid [BMIM][NO₃]. The reaction yields are typically increased to >85% and the products are isolated by ethanol-mediated precipitation direct from the ionic liquid, requiring no further purification.     

Expeditious,Nano-BF3 · SiO2-Catalyzed Michaelis–Arbuzov Reaction in an Ionic Liquid: Synthesis of Privileged Aryl/Heterocyclic Phosphonates

An expeditious, simple, and green method was developed for the synthesis of privileged aryl/heterocyclicphosphonates, 8(a–c) to 13(a–c) through Michaelis–Arbuzov reaction of aryl/heterocyclic halides (Br), 1–6, and trialkylphosphites, 7(a–c), in room-temperature ionic liquid [bbim]Br using heterogeneous Lewis catalyst, nano-silica-supported boron trifluoride (BF₃-SiO₂). The advantages of this protocol are simplicity, good yield of the products, less reaction time (20–38 min), mild reaction conditions, easy workup, and reusability of the catalyst and ionic liquid. It is demonstrated that nano-BF₃-SiO₂ is a recoverable and easy accessible catalyst for the formation of C(sp²)-P bond in an ionic liquid.     

Phase behaviour of 1-methyl-3-octylimidazolium bis[trifluoromethylsulfonyl]imide with thiophene and aliphatic hydrocarbons: The influence of n-alkane chain length

This paper reports the results of a new experimental study on the capacity of an ionic liquid to extract a sulfur compound from its mixtures with aliphatic hydrocarbons. With this aim, liquid + liquid equilibrium data of ternary systems containing 1-methyl-3-octyl-imidazolium bis(trifluoromethylsulfonyl)-imide ([C₈mim][NTf₂]), thiophene and n-hexane, n-heptane or n-hexadecane have been determined at T = 298.15 K. All systems showed high solubility of thiophene in the ionic liquid and low solubility of the ionic liquid in the n-alkane. The solute distribution coefficient decreases and the selectivity increases as the chain length of n-alkane increases. Both parameters are higher than unity in most of the cases. The experimental results have been correlated using NRTL activity coefficient model, and large deviations from experimental data have been found at high concentrations of thiophene with the heaviest hydrocarbons.     

TEMPO-catalyzed oxidation of benzylic alcohols to aldehydes with the H2O2/HBr/ionic liquid [bmim]PF6 system

A selective oxidation of benzylic alcohols to the corresponding aldehydes in room temperature ionic liquid was achieved by using TEMPO/HBr/H₂O₂ system, and both ether-insoluble acetamido-TEMPO and ionic liquid [bmim]PF₆ can be successfully recovered and reused for the oxidation of the same (different) substrate.     

[Bmim]Cl/FeCl3离子液体催化α-生育酚与β-D-五乙酰葡萄糖的糖基化反应

以[Bmim]Cl/FeCl₃(三氯化铁/氯化丁基甲基咪唑)离子液体作为反应介质和催化剂, 考察了离子液体的酸度、反应温度及反应时间对α-生育酚与β-D-五乙酰吡喃型葡萄糖糖基化反应的影响. 结果表明, 离子液体的催化活性与其酸强度密切相关, 离子液体的酸性越强, 其对此糖基化反应催化活性越高. 在FeCl₃与[Bmim]Cl物质的量比为2的[Bmim]Cl/FeCl₃离子液中, α-生育酚与β-D-五乙酰吡喃型葡萄糖在45 ℃下反应3 h, 可以得到较高的转化率, α-生育酚的转化率最高可达70.2%. 同有机溶剂作为反应介质相比, 反应条件温和, 反应时间短, 室温离子液体具有更好的催化活性, 所得产物与离子液体不溶, 便于分离, 催化体系可循环使用, 且对环境友好.     

五种1-烷基-2,3-二甲基咪唑型离子液体的合成及作为Li/LiFeO_4电池电解液的研究

合成了五种新的1-烷基-2,3-二甲基咪唑二(三氟甲基磺酰)亚胺离子液体(alkyl-DMimTFSI).以离子液体作为Li/LiFeO4电池电解液,分别考察不同烷基(正丁基、正戊基、正辛基、异辛基和正癸基)对电解液理化性质、界面性质和电池行为的影响.结果表明离子液体的电化学窗口都可以达到5.6V(-0.4～5.2Vvs.Li+/Li),显示它们具有较好的电化学稳定性.加入碳酸亚乙烯酯作为添加剂后,离子液体电解液在Li负极形成稳定的固体电解质相界面膜(SEI),从而提高了Li负极的稳定性,保护了Li片不受腐蚀.电化学阻抗和循环伏安分析进一步揭示LiFeO4正极与离子液体电解液也有良好的兼容性.此外,研究还表明离子液体中烷基种类严重影响它们的电池行为.采用butyl-DMimTFSI和amyl-DMimTFSI电解液体系的电池充放电容量和可逆性明显优于另外三种离子液体,它们的首次放电容量分别达到145和152.6mAh/g,并表现出良好的充放电循环性能.因粘度最大,采用isooctyl-DMimTFSI电解液的电池首次放电容量仅为8.3mAh/g,但添加碳酸丙烯酯(质量比1∶1)稀释后首次放电容量上升至132.4mAh/g.     

Tandem isomerization-lactonization of olefinic fatty acids using the Lewis acidic ionic liquid, choline chloride·2ZnCl2

The tandem isomerization-lactonization of unsaturated fatty acids to their corresponding γ-lactones was carried out for the first time in the presence of a Lewis acidic ionic liquid, choline chloride·2ZnCl₂. The ionic liquid initially catalyzes the stepwise migration of the double bond along the carbon chain toward the carboxyl group at the Δ4 position, which subsequently undergoes lactonization resulting in the formation of γ-lactones. This one step process allows the formation of γ-lactone in good yield with little or no formation of δ-lactones. The studied ionic liquid plays the dual role of solvent as well as catalyst.     

Efficient nucleophilic substitution reactions of highly functionalized allyl halides in ionic liquid media

Nucleophilic substitution reactions of highly functionalized allyl halides with three anions, N₃⁻, AcO⁻, and PhSO₂⁻, in ionic liquid media were conducted. The ionic liquid, [Bmim][BF₄], was found to be superior to classical organic solvents to give higher yields and faster reaction rates. The resulting products belong to multifunctionalized trisubstituted α,β-unsaturated ketones, which are useful building blocks for organic synthesis.     

Ionic liquid of [Bmim]Cl for the preparation of hierarchical nanostructured rutile titania

The rutile titania with hierarchical nanostructure was conveniently prepared in a room temperature ionic liquid (RTIL) of [Bmim]⁺Cl⁻ system. The obtained materials were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ adsorption-desorption analysis. XRD patterns revealed that only rutile phase was formed in the ionic liquid of [Bmim]⁺Cl⁻. The SEM and TEM micrographs as well as N₂ adsorption-desorption measurements showed that the nanorods of rutile titania were interaggregated to fabricate a large mesoporous structure and the voids packed in the nanorods formed a small mesostructure. It was proposed that the formation of rutile crystal phase was due to high acidity and high Cl⁻ content in the special reaction media, and also the combination of ionic liquid-templated effects with so-called reaction limited aggregation resulted in the hierarchical nanostructure.     

Conjugate addition of indoles to α,β-unsaturated ketones using Cu(OTf)2 immobilized in ionic liquids

Indoles undergo smooth conjugate addition with α,β-unsaturated ketones in the presence of 10 mol% copper(II) triflate immobilized in air and moisture stable [bmim]BF₄ ionic liquid under mild conditions to afford the corresponding conjugate addition products in high to quantitative yields. The recovery of Cu(OTf)₂ is facilitated by the ionic liquid. The recovered catalyst was reused four to five times with consistent activity.