新型室温离子液体六烷基胍盐的制备及性质

近年来 ,离子液体 (IL)作为“绿色”溶剂受到学术和工业界的关注 .英国 BP公司和法国的 IFP等研究机构从 2 0世纪 80年代起就开始探索离子液体作为溶剂与催化剂的可能性 ,至今在离子液体体系中已实现了许多催化反应 [1～ 5] .室温离子液体 (RTIL S)是指在常温下呈液态的熔盐体系 .通常由烷基吡啶或双烷基咪唑季铵阳离子与氯铝酸根、氟硼酸根及氟磷酸根等阴离子组成 .在季铵盐类离子液体中 ,咪唑盐的合成和应用研究尤为突出 .目前 ,对于既可作为溶剂又可作为催化剂的室温离子液体的合成和应用已成为研究热点 [6 ] ,如室温离子液体 [EMI…     

室温离子液体在过渡金属催化反应中的应用研究进展

室温离子液体(RTILs)是在室温或近于室温下呈液态的由离子构成的盐类．如图1所示，RTILs按阳离子类型可以分为4类：烷基季铵盐离子；烷基季鳞盐离子；N，N-二烷基咪唑离子和N-烷基吡啶离子．按阴离子可分为：氯化盐 AlX3(X=卤素)和含有RF1^-,PF6^-等阴离子的离子液体．     

新型二茂铁甲基季铵盐离子液体的合成与表征

以二茂铁与二甲胺为原料合成了碘化二茂铁甲基季铵盐,再经复分解反应得到乙酸二茂铁甲基季铵盐离子液体;表征了离子液体的结构,测定了其熔点和溶解性.结果表明,合成的乙酸二茂铁甲基季铵盐离子化合物熔点低于100℃,是一种新型的二茂铁甲基季铵盐离子液体.     

离子液体作为微波吸收剂促进苯甲醛与巴比妥酸的缩合反应

离子液体是纯粹由离子组成的液体,通常由二烷基季铵阳离子与四氟硼酸根、六氟磷酸根、卤素负离子等阴离子组成.离子液体具有强极性、低蒸汽压,对无机和有机物具有良好的溶解性以及对绝大部分试剂稳定等一系列特殊性质,常作为反应介质或催化剂用于有机合成中[1,2].     

氯铝酸离子液体介质中醚化反应的研究

 在1－烷基吡啶、1－甲基－3－烷基咪唑季铵盐或盐酸三甲铵与无水AlCl3构成的室温离子液体反应介质中，尝试进行了叔丁醇的醚化反应．结果表明，在中性或碱性氯铝酸离子液体中，叔丁醇与甲醇、乙醇、丙醇、丁醇或戊醇在80～140℃反应6～12h，可以得到较高的醇转化率和醚选择性，而且产物叔丁基醚和离子液体系分层，便于分离．     

聚季铵盐离子液体材料制备及其对蛋白质吸附性能评价

通过一步合成法制备了两种可聚合季铵盐离子液体功能单体,并通过沉淀聚合法合成了相应的聚离子液体聚合物。对产物进行了核磁共振、扫描电镜、热重分析等表征。结果表明:所制备的两种材料粒径均匀,约为600 nm的椭球形颗粒,颗粒之间有相互粘连。通过对牛血清白蛋白(BSA)、卵清蛋白(OVA)、牛血红蛋白(BHb)、溶菌酶(Lys)、胰蛋白酶(Try)5种蛋白质的吸附性能实验,考察了聚季铵盐离子液体材料对蛋白质的吸附性能。考察结果表明:两种聚离子液体材料均对蛋白质具有一定的吸附性能。其中以4-乙烯基苄氯季铵盐离子液体为功能单体制备的聚离子液体材料对胰蛋白酶的吸附性能最好,是一种具有良好应用前景的材料。     

离子液体的量化计算及分子动力学模拟研究进展

离子液体是由有机阳离子和无机/有机阴离子构成的盐类,一般在室温或接近于室温下呈液态,因此常被称为室温离子液体(RTIL).依据不同的划分标准,离子液体有多种分类方式:根据年代的不同可将离子液体分为第一代、第二代及第三代离子液体,例如:烷基咪唑和烷基吡啶的金属卤化物盐等[1];根据阳离子的不同可将离子液体分为季鏻     

手性离子液体的合成

过去十多年来,由于具有较高的热化学稳定性和溶解性、低毒、低挥发、不可燃、可循环等特点,离子液体(IL)引起了许多研究者的关注.手性离子液体(CIL)作为一种特殊的离子液体具有特性,除了能用于手性鉴别、外消旋化合物的选择性拆分及手性固定相等方面,还可以作为溶剂或催化剂应用于不对称有机合成中.综述了近五年来咪唑盐类、吡啶盐类、噻唑盐类、季铵盐和铵盐类及其它盐类手性离子液体的新进展.     

手性离子液体研究进展

对近几年来手性离子液体的研究进展进行了全面综述,这些手性离子液体包括咪唑鎓盐、季铵盐、噁唑啉盐、噻唑啉盐、吡啶盐等;重点评述了手性离子液体的合成以及它们在有机化学中的应用,如作为反应溶剂和相转移催化剂、手性溶剂,手性助剂和手性位移试剂等。     

新型氮二烷基吗啉盐酸盐离子液体的合成及其性能研究

以N-甲基吗啉和N-乙基吗啉为原料合成了系列新型的氮二烷基吗啉季铵盐类离子液体, 所有新化合物经元素分析、1H NMR确认了其结构, 同时测定了该类化合物的热稳定性、电导率以及对聚丙烯腈的溶解能力. 试验结果表明, 大多数化合物的熔点较低, 为室温离子液体. 该类化合物具有较好的热稳定性, 可应用于电极和表面活性剂领域. 且N-甲基-N-丁基吗啉盐酸盐具备对聚丙烯腈的溶解能力.     

Selective extraction of CO2 from simulated flue gas using polymeric ionic liquid sorbent coatings in solid-phase microextraction gas chromatography

The CO₂ selectivity of two polymeric task-specific ionic liquid sorbent coatings, poly(1-vinyl-3-hexylimidazolium) bis[(trifluoromethyl)sulfonyl]imide [poly(VHIM-NTf₂)] and poly(1-vinyl-3-hexylimidazolium) taurate [poly(VHIM-taurate)], was examined using solid-phase microextraction (SPME) for the determination of CO₂ in simulated flue gas. For comparison purposes, a commercial SPME fiber, Carboxen™-PDMS, was also studied. A study into the effect of humidity revealed that the poly(VHIM-taurate) fiber exhibited enhanced resistance to water, presumably due to the unique mechanism of CO₂ capture. The effect of temperature on the performance of the PIL-based and Carboxen fibers was examined by generating calibration curves under various temperatures. The sensitivity, linearity, and linear range of the three fibers were evaluated. The extraction of CH₄ and N₂ was performed and the selectivities of the PIL-based and Carboxen fibers were compared. The poly(VHIM-NTf₂) fiber was found to possess superior CO₂/CH₄ and CO₂/N₂ selectivities compared to the Carboxen fiber, despite the smaller film thicknesses of the PIL-based fibers. A scanning electron microscopy study suggests that the amine group of the poly(VHIM-taurate) is capable of selectively reacting with CO₂ but not CH₄ or N₂, resulting in a significant surface morphology change of the sorbent coating.     

Role of counteranions in polymeric ionic liquid-based solid-phase microextraction coatings for the selective extraction of polar compounds

A polymeric ionic liquid (PIL) poly(1-vinyl-3-hexylimidazolium chloride) (poly(ViHIm⁺Cl⁻)) was designed as a coating material for solid phase microextraction (SPME) to extract polar compounds including volatile fatty acids (VFAs) and alcohols. The extracted analytes were analyzed by using gas chromatography (GC) coupled with flame ionization detection (FID). Extraction parameters of the HS–SPME–GC–FID method, such as ionic strength, extraction temperature, pH and extraction time were optimized. Calibration studies were carried out under the optimized conditions to further evaluate the performance of the PIL-based SPME coating. For comparison purposes, the PIL poly(1-vinyl-3-hexylimidazolium bis[(trifluoromethyl)sulfonyl]imide) (poly(ViHIm⁺NTf₂⁻)) was also used as the SPME coating to extract the same analytes. The results showed that the poly(ViHIm⁺Cl⁻) PIL coating had higher selectivity towards more polar analytes due to the presence of the Cl⁻ anion which provides higher hydrogen bond basicity than the NTf₂⁻ anion. The limits of detection (LODs) determined by the designed poly(ViHIm⁺Cl⁻) PIL coating ranged from 0.02 μg L⁻¹ for octanoic acid and decanoic acid and 7.5 μg L⁻¹ for 2-nitrophenol, with precision values (as relative standard deviation) lower than 14%. The observed performance of the poly(ViHIm⁺Cl⁻) PIL coating was comparable to previously reported work in which commercial or novel materials were used as SPME coatings. The selectivity of the developed PIL coatings was also evaluated using heptane as the matrix solvent. This work demonstrates that the selectivity of PIL-based SPME coatings can be simply tuned by incorporating different counteranions to the sorbent coating.     

Nuclear magnetic relaxation and diffusion study of the ionic liquids 1-ethyl- and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide confined in porous glass

The molecular dynamics of the room-temperature ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Bmim Tf2N) confined in porous glass is studied by nuclear magnetic resonance (NMR) relaxometry and diffusometry and is compared with the bulk dynamics over a wide temperature range. The molecular reorientation processes for anions and cations alike are found to be significantly affected by the presence of the glass interface at high temperatures. In this respect, the ionic liquid behaves similarly to polar liquids where proton NMR relaxation is governed by reorientations mediated by translational displacements (RMTDs). This process becomes less significant towards lower temperatures when the characteristic translational correlation times of the ions approach a timescale comparable with those of the RMTD process, and the relaxation dispersions in bulk and in confinement become similar below a temperature corresponding to about 1.2T_g, a value where the onset of dynamic heterogeneity has been observed before. The self-diffusion coefficient, on the other hand, is found to be strongly reduced than the bulk within the accessible temperature range of 248 K and above and is significantly slower than expected from the tortuosity effect, suggesting that ion–surface interactions affect the macroscopic properties.     

Poly (L-phenylalanine-paired ionic liquid) as halogen-free heterogeneous nanocatalyst toward regiospecific 1,3-dipolar cycloaddition reaction

Although amino acid-paired ionic liquids (IL [AA]) have attracted considerable attention due to their environmental-friendly nature and providing abundant catalytic active sites, polymerized eco-friendly ILs have been rarely reported. Herein, we introduce a novel polymerized L-phenylalanine-paired ionic liquid (PIL [Phe]), synthesized in a new smart manner, as a promising heterogeneous nanocatalyst for regiospecific 1,3-dipolar cycloaddition reaction. For this purpose, new polymerizable ionic liquid (3-(3-aminopropyl)-1-vinylimidazolium (L)-2-amino-3-phenylpropanoate ([AVIm][Phe])) was designed and constructed as a halogen-free multifunctional monomer. The successful fabrication of chiral IL was approved by different techniques including ¹H NMR, FT-IR, and elemental analysis. Next, a green precipitation polymerization approach was applied using a water-soluble initiator under mild conditions. Co₃O₄@PIL [Phe] was synthesized by in situ copolymerization of the [AVIm][Phe] with ethyleneglycoldimethacrylate (EGDMA) (as non-ionic cross-linker) supported on magnetic Co₃O₄@MPS. The obtained data reveal that the supported polymerized form of [AVIm][Phe] is more efficient due to the formation of a porous structure with high-specific surface area (235.5 m²/ g) and a cross-linked network with high thermal stability (35% weight loss around 600 °C). In the following, the proposed Co₃O₄@PIL [Phe] nanostructure was applied as a magnetic catalyst toward the preparation of new and reported pyrrolidinyldispirooxindoles; and it displayed accelerated mass transfer due to its large pore volume (0.85 cm³/ g), and numerous accessible active sites. Consequently, a range of pharmaceutical dispirobisoxindole scaffolds with broad structural diversity were readily obtained in excellent yields (>92%) and high regioselectivity under environmental conditions.     

The absorption of organic liquids in poly(aryl-ether-ether-ketone) [PEEK]

The absorption and subsequent desorption of benzene, toluene, carbon disulfide, and chloroform in amorphous and 27% crystalline poly (aryl-ether-ether-ketone) (PEEK) were determined. At 35°C, the equilibrium weight gain (solubility) of benzene, toluene, chloroform, and CS₂ are 23.5, 19.8, 51.2, and 21.2 wt%, respectively. The initial weight gain is linear with root-time and pseudodiffusion constants for absorption into amorphous PEEK ranging from 0.35 to 9.85 x 10^-12m²/s were calculated. The desorption processes are two-step and are controlled by the T_g of the penetrant-resin mixture. The rate of diffussion into the crystalline material is extremely slow; crystalline PEEK reaches saturation (12.5 wt%) after immersion in CS₂ (35°C) for several hundred hours but, even after 1300 h immersion, the other fluids do not reach saturation.     

Direct Electrochemistry of Hemoglobin in Layer‐by‐Layer Films Assembled with DNA and Room Temperature Ionic Liquid

Based on electrostatic interaction and electrodeposition, poly‐anionic deoxyribonucleic acid (DNA), room temperature ionic liquid 1‐butyl‐3‐methyl‐imidazolium tetrafluoroborate (BMIMBF₄), hemoglobin (Hb) and Poly(diallyldimethylammonium chloride) (PDDA) were successfully assembled into Hb/IL/DNA/PDDA layer‐by‐layer complex films on the surface of ITO electrode. FTIR spectroscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the composite film. The obtained results demonstrated that the Hb molecule in the film kept its native structure and showed its good electrochemical behavior. A pair of well‐defined redox peaks of Hb with the formal potentials (E°′) of ?0.180 V (vs. SCE) was appeared in phosphate buffer solution (PBS, pH 7.0). The Hb/IL/DNA/PDDA/ITO modified electrode also showed an excellent electrocatalytic behavior to the reduction of hydrogen peroxide (H₂O₂). Therefore, the IL/DNA/PDDA complex film as a novel matrix open up a possibility for further study on the direct electrochemistry of other proteins and the fabrication of the third‐generation electrochemical biosensors.     

The polymeric ionic liquids/mesoporous alumina composites: Synthesis,characterization and CO2 capture performance test

The CO₂ capture materials and technology have received much attention in recent years due to the environmental deterioration caused by the greenhouse gas emissions. Several imidazolium polymeric ionic liquids (PILs) were synthesized and immobilized on mesoporous γ-Al₂O₃ (MA) using ultrasonic immersion method. The prepared adsorbents were characterized by FT-IR, ¹H NMR, EA, TGA, SEM, XRD, BET and TEM, indicating the successful synthesis of the desired PILs/MA. The CO₂ adsorption capacity was investigated under different loading ratios, temperatures, pressures and CO₂ flow rates, whose optimal adsorption conditions were 1/1, 313 K, 5 bar and 10 mL/min, respectively. Moreover, the adsorption curves for P[VCIm]Cl/MA were coincident with pseudo-second order model, and the CO₂ adsorption kinetics model was calculated and obtained. Compared with P[VRIm]Cl and P[VEIm]Cl, P[VCIm]Cl/MA demonstrated an outstanding adsorption amount of 0.562 mmol/g under the suitable conditions, and its regeneration efficiency could achieve 94.8% after 5 times cycle.     

基于离子液体固定二氧化碳的研究进展

综述了不同种类离子液体吸收固定CO2的研究进展,从离子液体的结构和分子模拟结果探讨了离子液体吸收CO2的机理及特征,展望了功能化离子液体在固定CO2方面的应用前景并分析了其在工业应用中存在的问题.     

离子液体的结构及其汽油萃取脱硫性能

用不同金属氯化物与氯代甲基咪唑合成离子液体,采用快原子轰击谱测定了这些离子液体的结构,并评价了这些离子液体对汽油萃取脱硫的能力.实验结果表明,由CuCl合成的离子液体中存在稳定的CuCl-2 ,Cu2Cl-3 和Cu3Cl-4 阴离子.这些阴离子可能通过Cu(I)与S的π络合作用而使离子液体具有较高的萃取脱硫效率.经六次萃取后,汽油中的硫含量可以从 650 μg·g-1降至 20~30μg·g-1.