Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids with Two Templates for the Simultaneous Solid-Phase Extraction of Fucoidan and Laminarin from Marine Kelp

Molecularly imprinted polymers modified by deep eutectic solvents and ionic liquids (ILs) were prepared as packing materials for the solid-phase extraction (SPE) of fucoidan and laminarin. The prepared materials were characterized by field emission scanning electron microscopy and Fourier transform infrared spectroscopy. The polymers modified by the deep eutectic solvent prepared by choline chloride and urea had the best extraction efficiencies for fucoidan and laminarin (95.5% and 87.6%, respectively) from marine kelp. The relative standard deviations for intraday and interday determination were less than 4.23%. The molecularly imprinted polymers modified by deep eutectic solvents and ILs showed outstanding applications for SPE and may offer novel sample pretreatment for other analytes.     

核磁共振波谱技术在室温离子液体研究中的应用*

室温离子液体作为一种绿色溶剂和功能材料,越来越引起人们的重视,其研究手段也越来越多。本文着重概述了核磁共振方法在测定离子液体的结构、纯度及性质,研究离子液体阴阳离子间的相互作用、离子液体与其他化合物的相互作用、离子液体及其在混合体系中的动力学特征、离子液体在溶液中的聚集行为,以及测定离子液体的热力学参数中的应用。     

Pyrylium sulfonate based ionic liquids

Pyrylium salts represent a new group of ionic liquids (ILs) containing a positive charge on the oxygen atom. The novel ILs were obtained starting with 4-pyrones from petroleum feedstock and renewable resources and sulfonic acids. The use of carboxylic acids instead of salts resulted in the formation of cocrystals. The synthesized pyrylium ionic liquids were stable in air and in contact with water and common organic solvents. The permanganate indices which are characteristic for prepared sulfonates were also investigated. The pyrylium ionic liquids were useful as immobilizers and dissolving agents in hydrosilylation reactions.     

离子液体表/界面性质与结构

离子液体与气体、溶剂等物质组成的多相体系为吸收、萃取、两相催化等技术的发展提供了新的平台。离子液体的表/界面性质与结构是含离子液体多相体系的重要科学问题,可在介观尺度下显著影响多相体系反应和分离过程的效率。近年来,离子液体表/界面性质和结构的研究得到了广泛的关注。本文综述了离子液体及其与水、有机溶剂组成的混合物的表/界面张力及结构研究进展,介绍了现有的研究方法、研究对象与研究成果,归纳了离子液体及其混合物表/界面张力及结构的变化规律,分析了表/界面结构与表/界面张力之间的关系,探讨了离子液体表/界面研究存在的问题和未来的发展方向。     

Amide-Based Ionic Liquid Electrolytes for Alkali-Metal-Ion Rechargeable Batteries

Ionic liquids (ILs) have a wide variety of applications in energy storage and material production. ILs are composed of only cations and anions, without any molecular solvents, and are generally known as “designer liquids (solvents)” because their physicochemical properties can be tuned by the combination of ionic species. In recent several decades, research and development activities of rechargeable batteries have garnered considerable attention because certain groups of ILs exhibit high electrochemical stability and moderate ionic conductivity, rendering them suitable for application in high-voltage batteries. ILs with amide anions are representative electrolytes and are extensively researched by many research groups, including our group. This paper focuses on amide-based ILs as electrolytes for alkali-metal-ion rechargeable batteries, introducing their history, characteristics, and existing challenges to be addressed.     

Synthesis and characterization of dicationic ionic liquids that contain both hydrophilic and hydrophobic anions

A series of dicationic ionic liquids, in which each dication is associated with both a hydrophobic anion and a hydrophilic anion, are synthesized. The thermal properties and solubility in organic solvents of these ILs are characterized. The ionic liquids show interesting properties, which are different from those of dicationic ionic liquids, in which each dication is associated with two identical anions.     

Thymopentin Magnetic Molecularly Imprinted Polymers with Room Temperature Ionic Liquids as a Functional Monomer by Surface-Initiated ATRP

Ionic liquids are also called “designer solvents.” In this article, we calculated the interaction energy of four ionic liquids with a template by molecular dynamics simulation. A simple approach was used to prepare biomacromolecule molecularly imprinted polymers for adsorbent and separation thymopentin (Tp5). In order to overcome intrinsic and increase structural selectivity, surface-initiated ATRP and ionic liquids (ILs) as functional monomer were used to prepare Fe3O4 molecularly imprinted polymers. Selective adsorption was applied to investigate the interactions between the polymers and lysine, phenylalanine, glutathione (GSH), and hemoglobin. The results demonstrated that Fe3O4 MIPs with 1-vinyl-3-ethyl acetate imidazolium chloride as functional monomer demonstrated high isolation and recognition of performance to the Tp5.     

Ionic liquids: solvents and sorbents in sample preparation

The applications of ionic liquids (ILs) and IL‐derived sorbents are rapidly expanding. By careful selection of the cation and anion components, the physicochemical properties of ILs can be altered to meet the requirements of specific applications. Reports of IL solvents possessing high selectivity for specific analytes are numerous and continue to motivate the development of new IL‐based sample preparation methods that are faster, more selective, and environmentally benign compared to conventional organic solvents. The advantages of ILs have also been exploited in solid/polymer formats in which ordinarily nonspecific sorbents are functionalized with IL moieties in order to impart selectivity for an analyte or analyte class. Furthermore, new ILs that incorporate a paramagnetic component into the IL structure, known as magnetic ionic liquids (MILs), have emerged as useful solvents for bioanalytical applications. In this rapidly changing field, this Review focuses on the applications of ILs and IL‐based sorbents in sample preparation with a special emphasis on liquid phase extraction techniques using ILs and MILs, IL‐based solid‐phase extraction, ILs in mass spectrometry, and biological applications.     

Liquid phase behavior of ionic liquids with alcohols: experimental studies and modeling

Ionic liquids (ILs) have been suggested as potential "green" solvents to replace volatile organic solvents in reaction and separation processes due to their negligible vapor pressure. To develop ILs for these applications, it is important to gain a fundamental understanding of the factors that control the phase behavior of ionic liquids with other liquids. In this work, we continue our study of the effect of chemical and structural factors on the phase behavior of ionic liquids with alcohols, focusing on pyridinium ILs for comparison to imidazolium ILs from our previous studies. The impact of different alcohol and IL characteristics, including alcohol chain length, cation alkyl chain length, anion, different substituent groups on the pyridinium cation, and type of cation (pyridinium vs imidazolium) will be discussed. In general, the same type of behavior is observed for pyridinium and imidazolium ILs, with all systems studied exhibiting upper critical solution temperature behavior. The impacts of alcohol chain length, cation chain length, and anion, are the same for pyridinium ILs as those observed previously for imidazolium ILs. However, the effect of cation type on the phase behavior is dependent on the strength of the cation-anion interaction. Additionally, all systems from this study and our previous work for imidazolium ILs were modeled using the nonrandom two-liquid (NRTL) equation using two different approaches for determining the adjustable parameters. For all systems, the NRTL equation with binary interaction parameters with a linear temperature dependence provided a good fit of the experimental data.     

Applications of functionalized ionic liquids

Recent developments of the synthesis and applications of functionalized ionic liquids (including dual-functionalized ionic liquids) have been highlighted in this review. Ionic liquids are at-tracting attention as alternative solvents in green chemistry, but as more functionalized ILs are pre-pared, a greater number of applications in increasingly diverse fields are found.     

离子液体与微波协同促进有机合成反应

介绍了离子液体作溶剂、助溶剂、催化剂和反应试剂与微波协同促进有机合成的研究进展。离子液体与微波协同促进有机合成反应,缩短了反应时间,提高了反应的选择性和产率,对环境更加友好。     

Effect of water and organic solvents on the ionic dissociation of ionic liquids

The effect of water and several organic solvents on the density, viscosity, and conductivity of ionic liquids (ILs) 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), 1-n-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), and 1-n-butyl-3-methylimidazolium trifluoroacetate ([bmim][CF3CO2]) was studied at 298.15 K in wide composition ranges. The density, viscosity, and conductivity of the three neat ILs were also determined at various temperatures. Upon the basis of the molar conductivity of the mixtures and that of the neat ILs of the same viscosity, the degree of dissociation of ILs in the solutions was investigated. It can be deduced that the organic solvents enhance the ionic association of the ILs, the effect depending on the solvent dielectric constant, while water promotes dissociation significantly due to its high dielectric constant and its ability to form strong hydrogen bonds with the anions of the ILs.     

Determination of ethanol in ionic liquids using headspace solid-phase microextraction–gas chromatography

The application of ionic liquids (ILs) as nonderivatizing solvents for the pretreatment and regeneration of cellulose is a growing area of research. Here we report the development of a rapid and simple method for the determination of residual ethanol content in two hydrophilic ILs, 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate. The method utilizes headspace solid-phase microextraction coupled with gas chromatography at elevated extraction temperatures, resulting in rapid equilibration times. The effect of IL water content on the ethanol extraction efficiency is presented. Recovery experiments carried out in real samples gave recoveries ranging from 96.8 to 98.2%.     

Interactions of 1-butyl-3-methylimidazolium carboxylate ionic liquids with glucose in water: a study of volumetric properties, viscosity, conductivity and NMR

Extensive applications of ionic liquids (ILs) may result in their accumulation in the ecological environment and organisms. Although ILs are popularly called "green solvents", their toxicity, in fact, has been exhibited. Therefore the interaction of ILs with biomolecules is a cutting-edge research subject. Herein, the interactions of 1-butyl-3-methylimidazolium carboxylate ionic liquids ([C(4)mim][HCOO], [C(4)mim][CH(3)COO] and [C(4)mim][CH(3)CH(2)COO]) with glucose in water were studied for their volumetric properties, viscosity, conductivity and NMR spectra. Limiting apparent molar volumes (V(Φ, IL)(0)), viscosity B-coefficients, limiting molar conductivities (Λ(0)) and Walden products (Λ(0)η(0)) were evaluated for the ILs in glucose + water solutions. Volumetric interaction parameters were also obtained from the transfer volumes of the ionic liquids. The contributions of the solvent properties (B(1)) and the ionic liquid-solvent interactions (B(2)) to the B-coefficient were extracted, together with molar activation energies (Δμ(IL)(0≠)) of the ionic liquids for viscous flow of the aqueous glucose + IL solution. In addition, the (13)C and (1)H NMR spectra of methyl β-D-glucopyranoside and ILs in β-D-glucopyranoside + IL + D(2)O were studied. The NMR results show that no special and strong interactions were observed between glucopyranoside and the ILs. However, it was confirmed that the H2 on the imidazolium ring has more activity (acidity) than atoms H4 and H5. The macro-properties and their changes were also discussed in terms of the size, structure and solvation of the ILs and glucose.     

Preparation of Room‐Temperature Ionic Liquids by Neutralization of 1,1,3,3‐Tetramethylguanidine with Acids and their Use as Media for Mannich Reaction

Abstract

New room‐temperature ionic liquids (ILs) were prepared by neutralization of 1,1,3,3‐tetramethylguanidine with different acids under ambient condition. The density, viscosity, decomposition temperature, electronic conductivity, and miscibility with some commonly used solvents were determined. As an example of the applications of the new ILs, the reaction of benzaldehyde, aniline, and acetophenone was carried out in the ILs. The ILs are easily prepared in large scale.     

Novel One-step Preparation of Functional Ionic Liquids Using Epoxides as Alkylation Reagents

Owing to their unique chemical and physical properties, ionic liquids (ILs) have received focus attention for application as solvent alternatives. ILs can be used in place of organic solvents in synthesis, catalysis, electrochem istry and liquid/liquid extractions. The commonly reported ILs have relied on pyridinium or imidazolium cations bearing simple alkyl groups.     

Useful Application of Acidic Ionic Liquids as Solvents in Baeyer–Villiger Oxidation with Hydrogen Peroxide for the Synthesis of Lactones

Cyclic ketones have been efficiently oxidized with hydrogen peroxide using acidic ionic liquids (ILs) as solvents. This is a new method for the synthesis of lactones with high yields that does not utilize any additional catalysts and enables ILs to be recycled.     

Ionic liquids as a medium for enantioselective catalysis

Over the last years, interest involving ionic liquids (ILs) used as reaction medium for homogeneous enantioselective catalysis has exponentially expanded. In many cases, the use of ILs provides several advantages over reactions in organic solvents in terms of activity and enantioselectivity. Even more important, the catalyst immobilization in IL can avoid its leaching and consequently favour its recycling. This review deals with recent advances in the investigation of these new solvents in asymmetric catalysis. We go over enzymes, chiral organocatalysts and metal complexes containing chiral ligands used in enantioselective processes using ionic liquids, with special emphasis on the catalyst reuse and also the separation of organic products.     

CO2/离子液体体系热力学性质的分子动力学模拟

超临界CO2和离子液体(ILs)是两种绿色溶剂. 离子液体可以溶解超临界CO2, 而超临界CO2不能溶解离子液体. 由此设计构成的CO2/IL二元系统, 同时具备了超临界CO2和离子液体的许多优点: 既可以降低离子液体的粘度, 还便于相分离, 是新型的耦合绿色溶剂. 其物理化学性质对于设计反应、分离等过程非常重要. 因此, 本文以CO2/IL二元系统为研究对象, 通过选择合适的分子力场和系综, 运用分子动力学(MD)模拟方法研究了CO2/[bmim][PF6]、CO2/[bmim][NO3]等体系的热力学性质. 结果表明, CO2对ILs膨胀度的影响非常小, 当CO2摩尔分数为0.5时, ILs膨胀仅为15%. CO2/ILs的扩散系数远小于CO2膨胀甲醇、乙醇溶液的扩散系数. 随着CO2含量的增加, ILs的扩散系数提高, 粘度显著下降, 表明CO2能有效地改善ILs扩散性, 减小其粘度. 因此CO2可用以改善离子液体溶剂体系的传递特性, 增强反应分离过程在其中的进行.     

Ionic liquids in sample preparation

Due to their unique properties, their good extractabilities for various target analytes, and the fact that many compounds are highly soluble in them, room-temperature ionic liquids (ILs) are used as promising alternatives to the traditional organic solvents employed in sample preparation. ILs have been used as extraction solvents for a wide range of analytes, from environmental contaminates to biomacromolecules and nanomaterials, and as dissolution solvents for various detection techniques. In this paper, the main applications of ILs in sample preparation are reviewed, and the problems and challenges in this area are described.