Sulfonic Acid-functionalized Ionic Liquid Research Articles

Sulfonic Acid Functionalized Ionic Liquids for Defect Passivation via Molecular Interactions for High-Quality Perovskite Films and Stable Solar Cells.

The high photoelectric conversion efficiency and low cost of perovskite solar cells (PSCs) have further inspired people's determination to push this technology toward industrialization. The high-quality perovskite films and high-efficiency and stable PSCs are the crucial factors. Ionic liquids have been proven to be an effective strategy for regulating high-quality perovskite films and high-performance PSCs. However, the regulation mechanism between ionic liquids and perovskites still needs further clarification. In this study, a novel sulfonic acid-functionalized ionic liquid, 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BSO3HMImOTf), was used as an effective additive to regulate high-quality perovskite films and high-performance devices. Microscopic mechanism studies revealed strong interactions between BSO3HMImOTf and Pb2+ ions as well as halogens in the perovskite. The perovskite film is effectively passivated with the controlled crystal growth, suppressed ion migration, facilitating to the greatly improved photovoltaic performance, and superior long-term stability. This article reveals the regulatory mechanism of sulfonic acid type ionic liquids through testing characterization and mechanism analysis, providing a new approach for the preparation of high-quality perovskite devices.

Preparation of sulfonic acid-functionalized polymeric ionic liquid-based magnetic adsorbent and its applications to diquat extraction

有效萃取复杂食品样品中的极性污染物是实现其准确测定的瓶颈,也是食品安全分析的难点。针对污染物的结构特点,设计和发展能与之产生特定作用的新型材料是高效萃取的关键。敌草快是一种广谱性除草剂,为碱性的阳离子有机化合物。该文以1-乙烯基咪唑和1,3-丙磺酸内酯为原料合成了磺酸功能化的离子液体,通过自由基聚合反应,将其固载至磁性纳米颗粒表面,得到磺酸功能化的聚(1-乙烯基-3-丙基磺酸基咪唑氯盐)修饰的磁性纳米颗粒(Poly([VPImi-SO3H][Cl])-MP)。采用红外光谱、扫描电镜、振动样品磁强计和热重分析等对其结构、形貌和磁性进行了表征。将其作为磁性固相萃取的吸附剂,萃取青菜中的敌草快。磺酸基的功能化使Poly([VPImi-SO3H][Cl])-MP的表面在一定pH下带有丰富的负电荷,与敌草快之间产生强的静电吸引作用,可实现对敌草快的有效萃取。对影响萃取效率的各种参数如溶液pH、吸附剂质量、吸附时间、解吸剂种类和体积等进行了优化。在优化条件下,结合磁性固相萃取和高效液相色谱技术,对方法的性能及适用性进行了考察。敌草快在0.2~20 μg/g内具有良好的线性(r=0.9981),检出限(S/N=3)和定量限(S/N=10)分别为0.09 μg/g和0.2 μg/g; 3个水平(0.5、1.0和2.5 μg/g)下的加标回收率为82.7%~97.5%,相对标准偏差为2.8%~5.0%(n=3)。结果表明,磺酸功能化的Poly([VPImi-SO3H][Cl])-MP能快速、有效地萃取敌草快,建立的方法能用于青菜中敌草快的准确测定。

Metal-Free, Adjustable, and Recyclable Catalytic Systems for the Construction of C–C Bonds by Activating Propargylic Alcohols

Pyrano[3,2-c]coumarin derivatives and C3-substituted 4-hydroxycoumarins as important skeletal structures of active natural products and pharmaceutically relevant molecules have received increasing attention. However, developing an adjustable system for selectively synthesizing them is still a challenging task. Herein, sulfonic acid-functionalized ionic liquid was successfully used as the catalyst for the alkylation of 4-hydroxycoumarin derivatives with secondary aromatic propargylic alcohols using dimethyl carbonate as the green solvent, giving up to 98% yield. On the other hand, protonated imidazole-based ionic liquid-catalyzed cyclization was also selectively achieved with a nearly quantitative yield. Developed metal-free catalytic systems exhibited well adjustable and recyclable properties, avoiding the contamination of metal and halogen, reducing the neutralization after the reaction, and benefiting the separation between the catalyst and the product. New strategies were applied for performing the gram-scale reaction smoothly. The adjustable systems might occur through two different mechanisms involving propargylic or allenic carbocation and hydrogen bonding effects between the catalysts and the substrates.

Sustainable and Reusable Sulfonic Acid-Functionalized Task-Specific Ionic Liquid Catalysts for Multicomponent Reactions. A Review

Improvements in Sustainable Organic Synthesis are usually related to the investigation of less hazardous, non-corrosive and renewable materials, as well as waste prevention, energy efficiency, solvent-free reactions, and the development of efficient reusable catalysts. In this context, multicomponent reactions emerged as important strategies for the rapid and more sustainable synthesis of organic molecules. In addition, the use of task-specific ionic liquids as non-conventional solvents and/or catalysts in multicomponent reactions has recently received great attention, contributing to the development of greener synthetic methodologies. This review describes the studies on the use of structurally diverse homogeneous and heterogeneous sulfonic acid-functionalized task-specific ionic liquids as acidic catalysts for multicomponent reactions applied to the synthesis of nitrogen- and oxygen-based heterocycles, as well as related compounds. The combination of the green credentials of multicomponent reactions and acidic ionic liquids are able to improve process sustainability and green metrics, contributing to sustainable chemical development and, ultimately, to economic growth and cleaner industrial production.

1,1′-Butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogensulfate: a versatile task-specific ionic liquid catalyst for the synthesis of 4H-pyran scaffolds through non-conventional process

In the present study, the catalytic efficiency of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogensulfate (BBSI-HSO4) as a versatile sulfonic acid-functionalized ionic liquid was demonstrated for the one-pot mechanosynthesis of pyrano[4,3-b]-pyrans using planetary ball mill at room temperature under solvent-free conditions. This efficient mechanosynthesis approach to the 4H-pyran scaffolds displays a combination of the structure–activity relationship of ionic liquids with ecological benefits of a mechanocatalytic procedure. The ionic liquid was easily recycled and reused several times with no significant loss of its catalytic activity.

Theoretical Elucidation of β-O-4 Bond Cleavage of Lignin Model Compound Promoted by Sulfonic Acid-Functionalized Ionic Liquid.

While the depolymerization of lignin to chemicals catalyzed by ionic liquids has attracted significant attention, the relevant molecular mechanism, especially the cleavage of specific bonds related to efficient depolymerization, still needs to be deeply understood for the complexity of this natural aromatic polymer. This work presents a detailed understanding of the cleavage of the most abundant β-O-4 bond in the model system, guaiacylglycerol β-guaiacyl ether, by a Brønsted acidic IL (1-methyl-3-(propyl-3-sulfonate) imidazolium bisulfate ([C3SO3Hmim][HSO4]) using density functional theory calculation and molecular dynamics simulation. It has been found that [C3SO3Hmim][HSO4] generates zwitterion/H2SO4 via proton transfer with an energy barrier of 0.38 kcal/mol, which plays a dominant role in the lignin depolymerization process. Subsequently, the reaction can be carried out via three potential pathways, including (1) the dehydration of α-C-OH, (2) dehydration of γ-C-OH, and (3) the protonation of β-O. The electrophilic attack of H2SO4 and the hydrogen-bonding interaction between GG and zwitterion are the two most important factors to promote the depolymerization reaction. In all steps, the dehydration of α-C-OH route is computed to be favored for the experiment. The relatively higher energy barrier for β-O-4 bond dissociation among these reaction steps is attributed to the hindrance of the self-assembled clusters of GG in the mixed system. Further, the dense distribution of H13([C3SO3Hmim]) surrounding O21(GG), indicated by sharp peaks in RDFs, reveals that -SO3H in cations plays a substantial role in solvating lignin. Hopefully, this work will demonstrate new insights into lignin depolymerization by functionalized ILs in biomass conversion chemistry.

Synthesis of new low-viscous sulfonic acid-functionalized ionic liquid and its application as a Brönsted liquid acid catalyst for the one-pot mechanosynthesis of 4H-pyrans through the ball milling process

In the present study, a new low-viscous sulfonic acid-functionalized ionic liquid (SAIL) viz. 4,4′-trimethylene-N,N′-sulfonic acid-dipiperidinium chloride was synthesized and characterized by FTIR, 1D and 2D NMR, and Mass spectra. Then, some properties of new SAIL were determined including pH, viscosity, density, and solubility in some common solvents. The catalytic activity of new SAIL was demonstrated for the one-pot mechanosynthesis of pyrano[4,3-b]pyrans, dihydropyrano[3,2-c]chromene and tetrahydrobenzo[b]pyrans using planetary ball mill under solvent-free conditions. This current mechanosynthesis methodology for the synthesis of 4H-pyran-annulated heterocyclic scaffolds displays a combination of the synthetic virtues of conventional multi-component reaction with ecological benefits and convenience of a simple mechanocatalytic procedure. New SAIL was easily recycled and reused several times with no significant loss of activity.

An Efficient Synthesis of Pyrrolidinone Derivatives in the Presence of 1,1′-Butylenebis(3-sulfo-3H-imidazol-1-ium) Chloride

The catalytic efficiency of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride as a sulfonic acid-functionalized ionic liquid was demonstrated for the synthesis of pyrrolidinone derivatives under mild conditions. The electronic effect of substituents on aniline derivatives was investigated. Further, a study on the structure–activity relationship of ionic liquids containing sulfonic groups for the synthesis of ethyl-2-(4-chlorophenyl)-4-hydroxy-5-oxo-1-(p-tolyl)-2,5-dihydro-1H-pyrrole-3-carboxylate was performed under optimal conditions. The results showed that the catalytic properties of ionic liquids containing two sulfonic or imidazole moieties with carbon spacers was superior to ionic liquids having one sulfonic or imidazole moiety with no carbon spacer.

Production of eco-friendly poly(oxymethylene) dimethyl ethers catalyzed by acidic ionic liquid: A kinetic investigation

Large scale green production of poly(oxymethylene) dimethyl ethers(DMMn) would be crucial if the diesel-DMMn blends were applied to tackle the worldwide formidable air pollution by particulate matter. Kinetics studies are of great significance among the core challenges for understanding the reaction principles and process design. Kinetic model was developed for the production of DMMn from methylal and trioxane with sulfonic acid-functionalized ionic liquid as catalyst. Reversible reactions of propagation-depolymerization were simultaneously considered with non-equal rate constants for complex sequential reactions. The kinetic model proposed showed good accuracy and consistency for both forward and backward reactions. Activation energies Ep were in the range of 35.7 to 39.6 kJ mol−1 for DMMn propagation reactions and 50.8 to 54.7 kJ mol−1 for DMMn decomposition, with the difference of −15.1 kJ mol−1 determined by Arrhenius equation. Entropy of activation, determined by Eyring-Polanyi equation, could make a significant contribution to the Gibbs energy barrier in the DMMn propagation/decomposition. It is interesting that the Schulz-Flory type distribution still could be maintained even the calculated rate constants increased with DMMn chain length.

A green and practical method for the synthesis of novel pyrano[2,3-c]pyrazoles and bis-pyrano[2,3-c]pyrazoles using sulfonic acid-functionalized ionic liquid

An efficient and practical protocol was developed for the synthesis of novel pyrano[2,3-c]pyrazoles and bis-pyrano[2,3-c]pyrazoles by one-pot four-component reaction of arylaldehyde, ethyl acetoacetate, hydrazine hydrate and dimethyl malonate using SO3H-functionalized ionic liquid [DMBSI]HSO4 as a potential green catalyst under solvent-free condition. The method presented is mild, environmentally friendly, inexpensive and functionality tolerant and produces the desired pyranopyrazoles in short reaction times (17–24 min) and excellent yields (85–95%). In addition, the catalyst can be reused at least ten times without almost any change in its catalytic activity.

Synthesis of 3-alkenylated indole and bis(indol-3-yl) derivatives catalyzed by sulfonic acid-functionalized ionic liquid under ultrasound irradiation

ABSTRACTA simple and efficient protocol has been developed for the synthesis of 3-alkenylated indoles and bis(indol-3-yl) derivatives by sulfonic acid-functionalized ionic liquid-catalyzed reaction of indole with 1,3-diketones/3-ketoesters under solvent-free ultrasound irradiation. Good to excellent yields (68–94%) are obtained in ultrasonication. The product of reaction is dependent on the substituent at C-2 position of indole. The catalyst is reusable and recyclable up to four cycles without significant loss of its catalytic activity. Compared with conventional heating, sound wave activation has the considerable advantages such as shorter reaction time, easy work-up, higher yields, and mild conditions.

Rapid and Efficient Synthesis of 1,4-Dihydropyridines using a Sulfonic Acid-functionalized Ionic Liquid

4-Aryl-l,4-dihydropyridines (1,4-DHPs) constitute a major class of drugs used in the management of cardiovascular diseases.1,2 They are analogues of NADH co-enzymes and an important class of drugs....

Kinetics of phenol alkylation with tert-butyl alcohol using sulfonic acid functional ionic liquid catalysts

N-methyl imidazole, pyridine and triethylamine based Bronsted acidic ionic liquids with sulfonic acid (–SO 3H) functionality were obtained using 1,4-butane sultone. They were tested in a batch reactor for catalytic activity in the tert-butylation of phenol with tert-butyl alcohol (TBA). The reaction time, reaction temperature and reactant mole ratio were optimized. Among the three ionic liquids, triethylammonium based sulfonic acid functionalized ionic liquid was found to be the most promising and gave the highest phenol conversion. A maximum phenol conversion of 86% with 57.6% selectivity to 4- tert-butylphenol (4-TBP) was achieved at a temperature of 70 °C at a low ionic liquid to phenol ratio. The catalyst retained its activity even after 5 recycles. A kinetic model was developed for the reaction mechanism based on the product distribution and the kinetic parameters were estimated. The activation energy for ionic liquid catalyzed alkylation of phenol was found to be 11.13 kcal/mol in the temperature range of 50–90 °C. Negative activation energy was observed for 2- tert-butylphenol (2-TBP) to 2,4-di- tert-butylphenol (2,4-DTBP) and the extended Arrhenius equation was used to interpret this trend.

Silica-supported sulfonic acid-functionalized ionic liquid coated with [bmim][PF6] as a scavenger for the synthesis of amides

The methodology of using a silica gel-supported functionalized ionic liquid as a scavenger in the purification of parallel synthesis products was demonstrated. Silica-supported sulfonic acid-functional ionic liquid was synthesized by etherification, aminate, and quaternary aminate from activated silica gel and 3-chloropropyl trimethoxysilane, imidazole, and 1,4-butanesultone, which was followed by acidification using trifluoromethanesulfonic acid and anion exchange with potassium hexafluorophosphate. A conventional ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate was then used to coat the surface of the silica gel. The silica-supported functionalized ionic liquid was used as a scavenger in the removal of excess amine in the parallel synthesis of amides. Desired products were obtained in excellent yields and purity with a sequestration time of less than 100 min at room temperature. After scavenging, the scavenger was easily filtered out and regenerated.

Continuous synthesis of d, l-α-tocopherol catalyzed by sulfonic acid-functionalized ionic liquid in supercritical carbon dioxide

Continuous synthesis of d, l-α-tocopherol catalyzed by a sulfonic acid-functionalized ionic liquid was conducted in supercritical carbon dioxide (SC-CO 2). The product was continuously separated from the reaction mixture by SC-CO 2 extraction during the course of reaction. Decompression of the supercritical fluid mixture downstream gave the product free of ionic liquid. The yield of d, l-α-tocopherol was improved with non-polar SC-CO 2 and polar propylene carbonate as solvents. The selectivity of d, l-α-tocopherol to trimethylhydroquinone (TMHQ) between CO 2-rich and ionic liquid-rich phase increased with the increase of pressure, and decreased with the increase of temperature at temperatures from 70 to 115 °C and pressures from 15 to 25 MPa. Effect of temperature, pressure and flow rate on the continuous synthesis of d, l-α-tocopherol was studied. The conversion of isophytol (IP) and the yield of d, l-α-tocopherol increased with decreasing pressure. The extraction rate of d, l-α-tocopherol increased with increasing pressure and decreased with increasing temperature. d, l-α-Tocopherol yield of 90.4% was obtained at 100 °C, 20 MPa and a CO 2 residence time of 12.6 min.

Nitration of aromatic compounds with NO2/air catalyzed by sulfonic acid-functionalized ionic liquids

Nitration of aromatic compounds with NO 2 /air catalyzed by sulfonic acid-functionalized ionic liquid under solvent-free conditions is reported. A variety of ionic liquids [BSPy][HSO 4 ], [BSPy][TfO], and [BSPy][pTSA] ([BSPy] = N -(4-hydroxsulfonylbutyl) pyridinium) were prepared. Their acidities were further investigated by Hammett method and the acidity-catalytic relationship was discussed. It was found that satisfactory results were obtained with [BSPy][HSO 4 ]. Ionic liquids could be conveniently separated with the products and reused for five times with excellent yield of mono-nitration products and para-selectivity.