- Physicochemical and thermodynamic properties of the {1-alkyl-1-methylpiperidinium bromide [C1Cn =2,4PIP][Br], or 1-butylpyridinium bromide, [C4Py][Br], or tri(ethyl)butylammonium bromide [N2,2,2,4] [Br] + water} binary systems
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This work is a continuation of our comprehensive study of ionic liquids, ILs (including organic salts with melting temperature above 100 °C) and their aqueous solutions as a novel alternative working pair for the absorption heat pump. A series of organic salts: 1-ethyl-1-methyl-piperidinium bromide, [C1C2PIP][Br], 1-butyl-1-methyl-piperidinium bromide, [C1C4PIP][Br], 1-butylpyridinium bromide, [C4Py][Br] and tri(ethyl)butylammonium bromide, [N2,2,2,4][Br] have been synthesized. The structures of compounds have been confirmed using NMR spectra. The basic thermal characterization of pure organic salts, including temperature and enthalpy of phase transition (Ttr, ΔtrH), temperature and enthalpy of melting (Tfus ΔfusH) have been measured using a differential scanning microcalorimetry technique (DSC). The physico-chemical properties that are: density (ρ) and dynamic viscosity (η) of the tested binary systems have been determined at wide temperature and composition range. From experimental densities data, the apparent molar volumes (V?,1) were calculated. In order to obtain limiting apparent molar volumes (V?,1 0), the concentration dependence of apparent molar volumes was correlated with Redlich–Mayer type equation. Additionally, the limiting molar expansibilities (E? 0) and isobaric thermal expansion coefficients (αP) have been calculated. Temperature dependence of the dynamic viscosity has been correlated using VFT equation. The solid?liquid phase equilibria (SLE) have been determined using a dynamic method and correlated using NRTL equation. The influence of the alkyl chain length in the piperidinium cation substituent, as well as the cation structure, on investigated properties are presented and discussed.
- Królikowska, Marta,Zawadzki, Maciej,Kuna, Tomasz
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- Novel ionic liquid analogs formed by triethylbutylammonium carboxylate-water mixtures for CO2 absorption
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This work presents ten ionic liquid analogs of triethylbutylammonium carboxylate and water as CO2 absorbents. The mixtures are liquids with relatively low viscosities at ambient temperature. The absorption experimental results have shown that each of them has fast absorption rate and large absorption capacity of CO2.
- Wang,Dai,Hu,Xiao,Wu,Zhang,Zhou
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- Low viscosity amino acid ionic liquids with asymmetric tetraalkylammonium cations for fast absorption of CO2
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Fifteen novel amino acid ionic liquids (AAILs) were prepared by the combination of several tetraalkylammonium cations with four amino acid anions ([Gly], [l-Ala], [β-Ala] and [Val]).The asymmetry of the tetraalkylammonium cations is shown to have a significant influence on the viscosity of the ionic liquids composed of amino acid anions, especially for the four triethylbutylammonium ([N2224])-based ionic liquids that have viscosities of lower than 60 mPa s, with the lowest being only 29 mPa s. The low viscosity tetraalkylammonium-based AAILs are further demonstrated to improve apparently the reaction and mass transfer rates of CO2 in the ionic liquids.
- Yu, Hong,Wu, You-Ting,Jiang, Ying-Ying,Zhou, Zheng,Zhang, Zhi-Bing
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- New chemical family of [n-CxH(2X+1)Net3][BeT3Me] showing ionic plastic-crystal (x = 4, 5), rotator-crystal (x = 6, 7) and liquid-crystal phases (X = 816)
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New ionic liquid crystals of [n-CxH(2x+1)NEt3][BEt3Me] (abbreviated to [CxNEt3][BEt3Me]) were detected for species with even numbers of 8 ˉ x ˉ 16. In contrast, plastic- and rota
- Yamada, Yudai,Kashimoto, Erina,Honda, Hisashi
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- Complex-precipitation using functionalized chiral ionic liquids with L-proline anion and chromatographic analysis for enantioseparation of racemic amino acids
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As one kind of functionalized green medium, chiral ionic liquids (CILs) have been widely applied in fields of asymmetric catalysis, enantioseparation, and so on. In this study, four kinds of amino acid–based CILs were synthesized by using trimethylamine, N-methylpyrrolidine, N-methylimidazole, and tropine as cationic nucleus, respectively. Then their specific optical rotation and solubility in common solvents were determined for further resolution application. The effect of different cations in these CILs was explored on the separation of racemic phenylalanine in complex-precipitation way. Moreover, various factors were systematically investigated for their effects on resolution efficiency, including the type of additive copper salts, the molar ratio of Cu (II) to CIL, pH value, the amount of racemic phenylalanine, and temperature. Under the appropriate conditions, L-phenylalanine mainly existed in solid phase and could be separated from its enantiomers in liquid phase. Furthermore, the mechanism of resolution was studied by thermogravimetric analysis, infrared spectrum, and molecular simulation. The resolution system has characteristics of no organic solvent, fast separation speed, simple resolution process, and easy scale-up.
- Zang, Huimin,Yao, Shun,Luo, Yingjie,Tang, Dan,Song, Hang
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- A novel twin-nest-shaped supramolecular cluster compound [Et 3N(n-Bu)]4[(Mo2O2S 6Cu6I6)]: Synthesis, crystal structure, and characterization
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The crystals of the title compound were obtained from the reaction of (NH4)2MoO2S2, CuI, and {Butyltriethylammonium Bromide} in DMF solution. The cluster anion consists of two nest-shaped fragments interconnected through a four-membered Cu(I) 2Cu ring. The structure of the cluster has been characterized by X-ray diffraction: Triclinic, space group P-1; a = 11.9107(11) A, b = 12.8125(12) A, c = 13.0194(12) A; α = 66.9650(10)°, β = 77.7370(10)°, γ = 88.4650(10)°; Volume = 1783.2(3) A3; Z = 1. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file. Copyright Taylor & Francis Group, LLC.
- Shen, Li-Xia,Li, Xing-Hui,Wu, Huan-Huan,Yue, Zhong-Cheng,Li, Li,Zhang, Zhen-Hua,Niu, Yunyin
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- Improving Cellulose Dissolution in Ionic Liquids by Tuning the Size of the Ions: Impact of the Length of the Alkyl Chains in Tetraalkylammonium Carboxylate
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Twenty ionic liquids based on tetraalkylammonium cations and carboxylate anions have been synthesized, characterized, and tested for cellulose dissolution. The amount of cellulose dissolved in these ionic liquids depends strongly on the size of the ions:
- Meng, Xiangqian,Devemy, Julien,Verney, Vincent,Gautier, Arnaud,Husson, Pascale,Andanson, Jean-Michel
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- A spectroscopic and molecular dynamics simulation approach towards the stabilizing effect of ammonium-based ionic liquids on bovine serum albumin
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In this article, we have explored the impact of ammonium-based ionic liquids (ILs) on the thermal unfolding/refolding of bovine serum albumin (BSA) in aqueous solutions using thermal circular dichroism (CD) spectroscopy and molecular dynamic simulation studies. In attempting to find ILs that can stabilize BSA at higher temperatures, we found good results with ammonium-based ILs. Our results show that the hydrophobicity of the IL is very crucial in the refolding phenomenon. A more hydrophobic IL, triethylhexylammonium bromide, shows better refolding of thermally denatured BSA and the stabilization is found to be dependent on the concentration of the IL. Moreover, fluorescence measurements (synchronous, life time, 8-anilino-1-naphthalenesulfonic acid (ANS)) were used to decipher the conformational changes of the protein in the IL medium. The spectroscopic studies suggest that the native state of BSA is not altered in the IL medium, rather a compact structure of BSA is established which is further supported by the molecular dynamics simulation analysis. In addition, the esterase-like activity of BSA was studied in the IL medium and the possible binding sites were investigated using a molecular docking program. We hope that the present study is successful in interpreting the possible mechanism of interaction between BSA and ILs as well as the stabilizing/destabilizing effect of ILs on BSA.
- Satish, Lakkoji,Millan, Sabera,Bera, Krishnendu,Mohapatra, Sujata,Sahoo, Harekrushna
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- Physicochemical characterization of MFm--based ammonium ionic liquids
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A series of ammonium-based ionic liquids (ILs), which share a homologous series of cations (CH3CH2)3N+(C nH2n+1) with n = 2, 4, 6, 8 and the anions with either BF4-, PF6-, or SbF6 -, was synthesized. Their structures were confirmed by 1H and 13C NMR, ESI-MS, and elemental analysis. Meanwhile, the content of impurity (e.g., water and bromide ions) was also determined using Karl Fischer titrator and ion chromatography. The thermal properties of the ILs were determined by TGA and DSC. Five of the investigated ILs have been shown to have a low melting point (2222]BF4, N,N,N,N-tetraethylammonium hexafluorophosphate, [N2222]PF6, N,N,N- triethylhexylammonium tetrafluoroborate, [N2226]BF4, N,N,N-triethyloctylammonium hexafluorophosphate, [N2228]PF 6 and N,N,N-triethyloctylammonium hexafluoroantimonate, [N 2228]SbF6. Densities, refractive indices, and miscibility of these 12 ILs were well studied systematically. Moreover, from the analysis of the structure-property relationship, the role of the alkyl chain length of the cation on these physical properties of the ILs has been assessed, and the influence of the nature of the anions on these experimental data of the ILs has been discussed. The studies may provide valuable contributions for the design and study of ILs.
- Li, Haifang,Zhao, Guoying,Liu, Fangfang,Zhang, Suojiang
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- Highly efficient and reversible H2S capture by mercapto carboxylic anion functionalized ionic liquids
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Four mercapto carboxylic anion functionalized ionic liquids (MCA-ILs) were designed and applied in H2S uptake. The solubility of H2S in MCA-ILs aqueous solution was measured from 303.2 to 333.2 K and pressure up to 1.0 bar. The reaction equilibrium thermodynamic model (RETM) was applied to fit the experimental data. Impressively, it was found that mercapto carboxylic anion captured H2S through 1:1 and 2:1 M ratio manner, which was supported by the results of RETM and quantum chemistry calculations. Furthermore, the solubility of H2S in 95% [P4444][MSA] could reach up to 0.9 mol/mol ILs and the enthalpy of the reaction was low (–22.21 kJ/mol). Considering the high H2S absorption capacity and low energy consumption of desorption, we believe that MCA-ILs solutions could provide an attractive alternative to be used as absorbent in H2S uptake.
- Wei, Liang,Geng, Zeyu,Liu, Yantong,Lu, Ruizhong,Xu, Yifan,Liu, Chunjie,Xu, Yun
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- Tetraalkylammonium-based ionic liquids for a RuCl3 catalyzed C–H activated homocoupling
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[BuEt3N][NTf2] can be a superior ionic liquid in a RuCl3 catalyzed oxidative C–H activation reaction compared to standard imidazolium-based ionic liquids. The tetraalkylammonium-based ionic liquid resulted in higher yields
- Muntzeck, Maren,Pippert, Felix,Wilhelm, René
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supporting information
(2020/06/09)
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- SO3H-functionalized Bronsted acidic ionic liquids as efficient catalysts for the synthesis of isoamyl salicylate
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Six Bronsted acidic ionic liquids (BAILs) composed of [HSO 4] were prepared, characterized, and used as catalysts of low dosage in the synthesis of isoamyl salicylate. The effects of various parameters such as the kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of salicylic acid were also examined in detail. The results suggested that the catalytic performances of BAILs were of close relevance to their Hammett acidities. The SO3H-functionalized BAILs 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate ([BSmim][HSO 4]) and N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate ([BSEt3N][HSO4]) of strong acidities exhibited excellently catalytic activities and selectivities in the esterification of salicylic acid with isoamyl alcohol. The fully optimized geometries of [BSmim][HSO4] and [BSEt3N][HSO4] further manifest that their strong acidities are derived from the strong interactions between the anion with the sulfonic acid group. In addition, it was found that [BSmim][HSO4] could be also recovered easily and used repetitively at least six times without obvious decline in activity and quantity.
- Tao, Duan-Jian,Wu, Jing,Wang, Zhen-Zhen,Lu, Zhang-Hui,Yang, Zhen,Chen, Xiang-Shu
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- Reaction of thiolesters with nitrogen ylides
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The pairing of unstabilized nitrogen ylides generated in situ with functionalized thiolesters under ambient conditions resulted in a new intramolecular carbon-carbon bond forming reaction. The scope of the reaction was illustrated with a series of substit
- Voltrova, Svatava,Srogl, Jiri
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supporting information; experimental part
p. 1677 - 1679
(2009/04/06)
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