262297-13-2Relevant articles and documents
Concentration-dependent apparent partition coefficients of ionic liquids possessing ethyl- and bi-sulphate anions
Jain, Preeti,Kumar, Anil
, p. 1105 - 1113 (2016)
This study deals with the concentration dependent apparent partition coefficients log P of the ethyl and bisulfate-based ionic liquids. It is observed that the bisulfate-based ionic liquids show different behaviour with respect to concentration as compared to ethyl sulphate-based ionic liquids. It is significant and useful analysis for the further implementation of alkyl sulfate based ionic liquids as solvents in extraction processes. The log P values of the ethyl sulphate-based ionic liquids were noted to vary linearly with the concentration of the ionic liquid, whereas a flip-flop trend with the concentration for the log P values of the bisulphate-based ionic liquids was observed due to the difference in hydrogen bond accepting basicity and possibility of aggregate formation of these anions. The π-π interactions between the imidazolium and pyridinium rings were seen to affect the log P values. The alkyl chain length of anions was also observed to influence the log P values. The hydrophobicity of ionic liquid changes with the alkyl chain in the anion in the order; [HSO4]- 4]- 4]-.
Choline chloride-thiourea, a deep eutectic solvent for the production of chitin nanofibers
Mukesh, Chandrakant,Mondal, Dibyendu,Sharma, Mukesh,Prasad, Kamalesh
, p. 466 - 471 (2014)
Deep eutectic solvents (DESs) consisting of the mixtures of choline halide (chloride/bromide)-urea and choline chloride-thiourea were used as solvents to prepare α-chitin nanofibers (CNFs). CNFs of diameter 20-30 nm could be obtained using the DESs comprising of the mixture of choline chloride and thiourea (CCT 1:2); however, NFs could not be obtained using the DESs having urea (CCU 1:2) as hydrogen bond donor. The physicochemical properties of thus obtained NFs were compared with those obtained using a couple of imidazolium based ionic liquids namely, 1-butyl-3-methylimidazolium hydrogen sulphate [(Bmim)HSO4] and 1-methylimidazolium hydrogen sulphate [(Hmim)HSO4] as well as choline based bio-ILs namely, choline hydrogen sulphate [(Chol)HSO4] and choline acrylate. The CNFs obtained using the DES as a solvent were used to prepare calcium alginate bio-nanocomposite gel beads having enhanced elasticity in comparison to Ca-alginate beads. The bio-nanocomposite gel beads thus obtained were used to study slow release of 5-fluorouracil, an anticancer drug.
A quick, simple, robust method to measure the acidity of ionic liquids
Gr?svik, John,Hallett, Jason P.,To, Trang Quynh,Welton, Tom
, p. 7258 - 7261 (2014)
Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of -1 to -9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe.
Efficient combination of recyclable task specific ionic liquid and microwave dielectric heating for the synthesis of lipophilic esters
Arfan, Atef,Bazureau, Jean Pierre
, p. 743 - 748 (2005)
Mild and efficient esterification reactions of carboxylic acids with neo-pentanol were carried out using task-specific ionic liquids with hydrogen sulphate counteranion under microwave irradiation. The latent acidity of the ionic liquid was introduced by
Development of Acidic Imidazolium Ionic Liquids for Activation of Kraft Lignin by Controlled Oxidation: Comprehensive Evaluation and Practical Utility
Klapiszewski, ?ukasz,Szalaty, Tadeusz J.,Kurc, Beata,Stanisz, Ma?gorzata,Zawadzki, Bartosz,Skrzypczak, Andrzej,Jesionowski, Teofil
, p. 361 - 374 (2018)
A novel, eco-friendly method for the activation of lignin by controlled oxidation was studied. The results obtained for six acidic imidazolium ionic liquids containing the hydrogen sulfate anion were compared. The key goal of this research was to increase the content of carbonyl groups in the lignin structure because these may play the main role in the transport of protons and electrons in active materials for electrochemical applications. By means of a variety of analytical techniques (FTIR, 13C CP/MAS NMR, and X-ray photoelectron spectroscopy; selected reactions to determine the presence of carbonyl groups; SEM; zeta-potential analysis; thermogravimetric analysis/differential thermogravimetric analysis; and porous structure analysis), it was determined that the product obtained after treatment with 3-cyclohexyloxymethy-1-methylimidazolium hydrogen sulfate had favorable properties, in terms of the target application. Electrochemical tests proved that the obtained materials could be used as anodes in lithium batteries. The results show that the activation of lignin with ionic liquids can increase its capacity and maintain stability.
Kinetics and quantum chemical study for cyclotrimerization of propanal catalyzed by Br?nsted acidic ionic liquids
Wu, Li,Li, Zhen,Wang, Fang,Lei, Min,Chen, Jing
, p. 86 - 93 (2013)
Several Br?nsted acidic ionic liquids (BAILs) were synthesized and used as catalysts for the cyclotrimerization of propanal. The acidity of different BAILs was explored and a preliminarily study of the relationship between catalytic activity and acidity was performed. The kinetics for the BAILs-catalyzed cyclotrimerization of propanal was studied systemically to determine the kinetic model and the kinetic parameters by taking [BSTMG][HSO4] as the representative catalyst. The effects of various parameters such as catalyst loading, reaction temperature on the kinetics were examined in detail. Besides, the structures of three representative BAILs and the interactions between propanal molecule and ionic pairs of BAILs were studied by means of quantum chemistry calculations.
Insights on the catalytic behaviour of sulfonic acid-functionalized ionic liquids (ILs) in transesterification reactions - voltammetric characterization of sulfonic task-specific ILs with bisulfate anions
Martini, María B.,Fernández, José L.,Adam, Claudia G.
, p. 2731 - 2741 (2021/02/12)
This work shows for the first time the link between the amount of free sulfuric acid (as detected by cyclic voltammetry) and the activity of sulfonic-acid-functionalized ionic liquids (ILs) as acid catalysts for a transesterification reaction, and demonstrates that sulfonic acid groups, while are not directly involved in the catalysis, release the free acid during the reaction. Two imidazolic ILs with bisulfate as the counterion and their corresponding task-specific ILs (TSILs) that resulted from the addition of a sulfonic acid group inside the imidazolic-base structure were studied. The outstanding catalytic activity at room temperature of the TSILs 1-(4-sulfonic acid)-butyl-3-methylimidazolium bisulfate ([bsmim]HSO4) and 1-(4-sulfonic acid)-butyl-imidazolium bisulfate ([bsHim]HSO4) for the transesterification ofp-nitrophenyl acetate with methanol was associated to the significant amounts of free sulfuric acid in equilibria with the ionic pairs. It was concluded that these TSILs function as reservoirs for releasing the free acid, which is the actual acid catalyst. In contrast, the corresponding non-sulfonic ILs supply very little amounts of free acid and consequently present low catalytic activities at room temperature, which in fact can be improved by increasing the reaction temperature up to 100 °C.
Preparation method of low-molecular olefin polymer
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Paragraph 0053, (2018/06/26)
The invention provides a preparation method of a low-molecular olefin polymer. The preparation method comprises the following steps: low-molecular olefin is subjected to a polymerization reaction under the action of a catalyst, and a product is collected; the catalyst is prepared from ionic liquid, polyphosphoric acid and heteropolyacid by mixing at 30-100 DEG C for 1-12 h. The preparation methodhas the advantages of mild reaction conditions, high conversion rate and good selectivity, and the catalyst is easy to recover and can be recycled; the preparation method is green and pollution-free.
