- Electrodeposition of zinc coatings from the solutions of zinc oxide in imidazolium chloride/urea mixtures
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To solve the inherent disadvantages in conventional processes for electrodeposition of zinc, it's necessary to develop more high-efficiency and environmentally friendly electrolytes. In this work, it was found that the dissolution of ZnO was remarkably enhanced in some imidazolium chloride by the addition of urea, and the solubility of ZnO in 1:1 [Amim]Cl/urea mixture was as high as 8.35 wt% at 373.2 K. Electrochemical measurements showed that zinc could be readily electrodeposited from the solutions of ZnO. Bright, dense and well adherent zinc coatings with good purity were obtained from 0.6 M solution of ZnO in 1:1 [Amim]Cl/urea at 323.2?343.2 K. It's expected that the solutions of ZnO in imidazolium chloride/urea mixtures have the potential to replace the traditional electrolytes, especially toxic zinc chloride-based ones for zinc electroplating, as well as preparation of zinc materials. Science China Press and Springer-Verlag Berlin Heidelberg 2012.
- Zheng, Yong,Dong, Kun,Wang, Qian,Zhang, Suo Jiang,Zhang, Qin Qin,Lu, Xing Mei
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Read Online
- Electrochemical and spectroscopic study of vanadyl acetylacetonate–ionic liquids interactions
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A panel of ionic liquids has been synthesized and their effect on the vanadyl acetylacetonate solubility in acetonitrile has been firstly assessed. 1-Butyl-3-methylimidazolium acetate showed an unprecedented result, increasing the VO(acac)2 solubility in acetonitrile of more than one magnitude order (from 0.06 M to 1.1 M) opening new interesting horizons for the possible applications of this vanadium complex. The electrochemical effect of the considered ionic liquids has been subsequently investigated through cyclic voltammetry and linear sweep voltammetry with rotating disk electrode, determining diffusion coefficient and kinetic current of VO(acac)2 in the considered media. In order to achieve a deeper understanding on the examined systems, VO(acac)2 solutions in acetonitrile ILs were eventually studied through IR, UV–vis, and EPR spectroscopies, finding evidences, corroborated by DFT studies, of the formation of strong adducts between VO(acac)2 and ILs.
- Guglielmero,Langroudi, Mo. Meskinfam,Khatib, M. Al,de Oliveira, M. Aysla Costa,Mecheri,De Leo,Mezzetta,Guazzelli,Giglioli,Epifanio, A. D',Pogni,Chiappe,Pomelli
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- A Robust Fungal Allomelanin Mimic: An Antioxidant and Potent π-Electron Donor with Free-Radical Properties that can be Tuned by Ionic Liquids
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Developing effective strategies to increase the chemical stability and to fine-tune the physico-chemical properties of melanin biopolymers by rational control of π-electron conjugation is an important goal in materials science for biomedical and technological applications. Herein we report that poly-1,8-dihydroxynaphthalene (pDHN), a non-nitrogenous, catechol-free fungal melanin mimic, displays a high degree of structural integrity (from MALDI-MS and CP/MAS 13C NMR analysis), a strong radical scavenging capacity (DPPH and FRAP assays), and an unusually intense EPR signal (g=2.0030). Morphological and spectral characterization of pDHN, along with deassembly experiments in ionic liquids, indicated amorphous aggregates of small globular structures with an estimated stacking distance of 3.9 ? and broadband absorption throughout the visible range. These results indicate that DHN-based melanins exhibit a high structural integrity and enhanced antioxidant and free-radical properties of potentially greater biomedical and technological relevance than for typical indole-based eumelanins.
- Manini, Paola,Lino, Valeria,Franchi, Paola,Gentile, Gennaro,Sibillano, Teresa,Giannini, Cinzia,Picardi, Emanuela,Napolitano, Alessandra,Valgimigli, Luca,Chiappe, Cinzia,d'Ischia, Marco
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p. 1331 - 1337
(2019/06/24)
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- A potential greener protocol for peptide coupling reactions using recyclable/reusable ionic liquid [ C 4-DABCO ] [ N(CN) 2 ]
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Abstract : Development of greener methodologies in synthetic organic chemistry has brought awareness in recent decades due to the ecological performance of green solvent media and catalytic systems. Here, we carried out the peptide bond formation reaction in one of the environmentally secure solvents, ‘ionic liquids’ in the presence of coupling reagent and in the absence of external base at room temperature, affording dipeptides in good to excellent yields. GRAPHICAL ABSTRACT: SYNOPSIS We carried out the peptide bond formation reaction in ionic liquids in the presence of a coupling reagent at room temperature, in the absence of an external base, affording dipeptides in good to excellent yields.
- Konwar, Manashjyoti,Khupse, Nageshwar D,Saikia, Prakash J,Sarma, Diganta
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- The effect of varying the anion of an ionic liquid on the solvent effects on a nucleophilic aromatic substitution reaction
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A variety of ionic liquids, each containing the same cation but a different anion, were examined as solvents for a nucleophilic aromatic substitution reaction. Varying the proportion of ionic liquid was found to increase the rate constant as the mole fraction of ionic liquid increased demonstrating that the reaction outcome could be controlled through varying the ionic liquid. The solvent effects were correlated with the hydrogen bond accepting ability (β) of the ionic liquid anion allowing for qualitative prediction of the effect of changing this component of the solute. To determine the microscopic origins of the solvent effects, activation parameters were determined through temperature-dependent kinetic analyses and shown to be consistent with previous studies. With the knowledge of the microscopic interactions in solution, an ionic liquid was rationally chosen to maximise rate enhancement demonstrating that an ionic solvent can be selected to control reaction outcome for this reaction type.
- Hawker, Rebecca R.,Haines, Ronald S.,Harper, Jason B.
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supporting information
p. 3453 - 3463
(2018/05/23)
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- Experimental study on CO2 sorption capacity of the neat and porous silica supported ionic liquids and the effect of water content of flue gas
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In this research, absorption of CO2 in different ionic liquids (ILs) is studied. Thus four ILs were synthesized containing 1-butyl-3-methylimidazolium as the cation and nitrate [NO3]?, thiocyanate [SCN]?, dicyanamide [N(CN)2]? and hydrogen sulfate [HSO4]? as the anions, respectively. The resulting ILs were then immobilized into activated silica support in a 1/1 IL/SiO2 weight ratio via the impregnation-vaporization method. CO2 sorption behavior of both neat and silica supported ILs (ILs-SiO2) were investigated at different temperatures and flow rates under atmospheric pressure, while their desorption process were carried out under 20?mm?Hg at 70?°C. In both sorbents, the best results were obtained at 25?°C with a flow rate of 12?mL/min, where [bmim][N(CN)2] with 1.85 (wt%) or 0.42?mmol CO2 per gram of sorbent and [bmim][HSO4]-SiO2 with 2.33 (wt%) or 0.53?mmol CO2 per gram of sorbent showed the highest sorption capacities. The effect of water on CO2 absorption capacity of the neat and silica supported ILs were also studied by transmission of CO2 gas flue containing 400?ppm water. The results indicated that the mass gain was higher when wet CO2 was passed through the sorbents, opposed to passing dry CO2. Because of the existence of a weak coulombic intraction between the sorbents and CO2, desorption occurs rapidly and a readily reuse of the sorbents is therefore provided.
- Mirzaei, Mojtaba,Badiei, Ali Reza,Mokhtarani, Babak,Sharifi, Ali
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p. 462 - 470
(2017/03/10)
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- First observation for dynamic solvent effect in ionic liquids
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We observed pressure effects on the rate of thermal fading of colored chromene 1 photochemically generated from 2 in ionic liquids. The reaction rates were retarded with increasing pressure in [C4-mim][CS], [bzl-mim][Tf2N], and [mnp-mim][Tf2N], whereas the reaction rate increased with pressures in [C4- mim][Tf2N]. These pressure-induced retardations, so-called dynamic solvent effects, result from the slow thermal fluctuations of solvents.
- Kitaoka, Satoshi,Nobuoka, Kaoru,Miura, Junji,Ohga, Yasushi,Ishikawa, Yuichi
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supporting information
p. 385 - 387
(2016/05/09)
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- Selective hydrogenation of phenol to cyclohexanone in water over PD@N-doped carbon derived from ionic-liquid precursors
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In this report, a kind of mesoporous N-doped carbon (CN-x) derived from N-containing ionic-liquid (IL) precursors were synthesized, and Pd@CN-x prepared by a simple ultrasound-assisted method showed higher catalytic activity for the selective hydrogenation of phenol and its derivatives under mild reaction conditions in water than commercial Pd@C and other common Pd heterogeneous catalysts. The catalytic activities of Pd@CN-x derived from different ILs were different, and further study into the influencing factors, including physical properties, N species of CN-x, and Pd status of Pd@CN-x, were performed. Being picky: N-Doped carbon (CN-x) derived from N-containing ionic-liquid precursors are used as Pd nanoparticle supports for the selective hydrogenation of phenol to cyclohexanone with high activity and selectivity under mild reaction conditions. The activities of the Pd@CN-x catalysts derived from a variety of ionic liquids are different, and studies on the physical properties, Pd status, and N species of the catalysts are performed.
- Xu, Xuan,Li, Haoran,Wang, Yong
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p. 3328 - 3332
(2015/04/16)
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- Eu3 + as a dual probe for the determination of IL anion donor power: A combined luminescence spectroscopic and electrochemical approach
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This work is aimed at giving proof that Eu(Tf2N)3 (Tf2N = bis(trifluoromethanesulfonyl)amide) can act as both an optical and electrochemical probe for the determination of the Lewis acidity of an ionic liquid anion. For that reason the luminescence spectra and cyclic voltammograms of dilute solutions of Eu(Tf2N)3 in various ionic liquids were investigated. The Eu2 +/3 + redox potential in the investigated ILs can be related to the Lewis basicity of the IL anion. The IL cation had little influence. The lower the determined halfwave potential, the higher the IL anion basicity. The obtained ranking can be confirmed by luminescence spectroscopy where a bathochromic shift of the 5D 0 → 7F4 transition indicates a stronger Lewis basicity of the IL anion.
- Babai, Arash,Kopiec, Gabriel,Lackmann, Anastasia,Mallick, Bert,Pitula, Slawomir,Tang, Sifu,Mudring, Anja-Verena
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p. 191 - 198
(2014/05/20)
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- Nonaborane and decaborane cluster anions can enhance the ignition delay in hypergolic ionic liquids and induce hypergolicity in molecular solvents
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The dissolution of nido-decaborane, B10H14, in ionic liquids that are hypergolic (fuels that spontaneously ignite upon contact with an appropriate oxidizer), 1-butyl-3-methylimidazolium dicyanamide, 1-methyl-4-amino-1,2,4-triazolium dicyanamide, and 1-allyl-3-methylimidazolium dicyanamide, led to the in situ generation of a nonaborane cluster anion, [B9H14]-, and reductions in ignition delays for the ionic liquids suggesting salts of borane anions could enhance hypergolic properties of ionic liquids. To explore these results, four salts based on [B10H13]- and [B9H 14]-, triethylammonium nido-decaborane, tetraethylammonium nido-decaborane, 1-ethyl-3-methylimidazolium arachno-nonaborane, and N-butyl-N-methyl-pyrrolidinium arachano-nonaborane were synthesized from nido-decaborane by reaction of triethylamine or tetraethylammonium hydroxide with nido-decaborane in the case of salts containing the decaborane anion or via metathesis reactions between sodium nonaborane (Na[B9H 14]) and the corresponding organic chloride in the case of the salts containing the nonaborane anion. These borane cluster anion salts form stable solutions in some combustible polar aprotic solvents such as tetrahydrofuran and ethyl acetate and trigger hypergolic reactivity of these solutions. Solutions of these salts in polar protic solvents are not hypergolic.
- McCrary, Parker D.,Barber, Patrick S.,Kelley, Steven P.,Rogers, Robin D.
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p. 4770 - 4776
(2014/05/20)
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- Probing the importance of ionic liquid structure: A general ionic liquid effect on an SNAr process
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The effect of a range of ionic liquids, with systematic variations in the cation and anion, on the rate constant of an aromatic substitution process was investigated. Temperature-dependent kinetic data allowed calculation of activation parameters for the process in each solvent. These data demonstrate a generalised ionic liquid effect, with an increase in rate constant observed in each ionic solvent, though the microscopic origins of the rate constant enhancement differ with the nature of the ionic liquid.
- Tanner, Eden E. L.,Hawker, Rebecca R.,Yau, Hon Man,Croft, Anna K.,Harper, Jason B.
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supporting information
p. 7516 - 7521
(2013/11/06)
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- A silver and water free metathesis reaction: A route to ionic liquids
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A versatile, cheaper, silver and water-free metathesis reaction was developed for imidazolium, phosphonium and pyrrolidinium based ionic liquids (ILs) associated with different anions such as dicyanamide, thiocyanate, tetrafluoroborate and bis(trifluoromethylsulfonyl)imide. This route, using the melt of amine chloride as a solvent and reagent, favours the ion exchange reaction using anion salts of Na or Li, yielding ionic liquids in high purity (≥99.5%) and high yields (≥90%). This route is particularly well adapted for water miscible ILs preparation.
- Srour, Hassan,Rouault, Helene,Santini, Catherine C.,Chauvin, Yves
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supporting information
p. 1341 - 1347
(2013/06/05)
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- Distinct influence of the anion and ether group on the polarity of ammonium and imidazolium ionic liquids
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The polarity of ionic liquids (ILs), usually denoted as ET(30) by the solvatochromic probe Reichardt's dye, is one of the most fundamental properties that remarkably affect the solvation and chemical reaction in ILs. It was generally accepted that the ET(30) of ILs was dominated by the nature of the cation. However, in this work, it was found that the common ammonium-based ILs showed strongly anion-dependent ET(30). For example, the ET(30) value for [N1124][DCA] and [N 1124][NTf2] is 49.0 and 59.0 kcal mol-1, respectively, while the corresponding imidazolium ILs bearing the same anions possess nearly identical ET(30), the ET(30) value for [BMIm][DCA] and [BMIm][NTf2] is 51.4 and 51.6 kcal mol-1, respectively. Moreover, introduction of an ether group was found to increase the ET(30) of imidazolium ILs while having no obvious effect on that of ammonium-based ILs. The Kamlet-Taft parameters and density functional theory (DFT) calculations indicated that the distinct result is related to different stabilization of the ground state of Reichardt's dye 30. In imidazolium ILs, the main interactions between ILs and zwitterionic dye involve both coulombic interaction (between the cation and the phenolate oxygen atom) and H-bonding interaction (between the acidic hydrogen on imidazolium ring and the phenolate oxygen atom). However, with the ammonium ILs lack of active hydrogen, the dye is only stabilized by the coulombic interaction between the cation and the phenolate oxygen atom. Interestingly, in both imidazolium and ammonium-based ILs, the spiropyran-merocyanine equilibrium exhibit obvious anion-dependent photochromism, solvatochromism, and thermal relaxation. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.
- Zhang, Shiguo,Chen, Zhengjian,Qi, Xiujuan,Deng, Youquan
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supporting information; experimental part
p. 1043 - 1050
(2012/07/14)
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- Hypergolic ionic liquids to mill, suspend, and ignite boron nanoparticles
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Boron nanoparticles prepared by milling in the presence of a hypergolic energetic ionic liquid (EIL) are suspendable in the EIL and the EIL retains hypergolicity leading to the ignition of the boron. This approach allows for incorporation of a variety of nanoscale additives to improve EIL properties, such as energetic density and heat of combustion, while providing stability and safe handling of the nanomaterials. The Royal Society of Chemistry 2012.
- McCrary, Parker D.,Beasley, Preston A.,Cojocaru, O. Andreea,Schneider, Stefan,Hawkins, Tommy W.,Perez, Jesus Paulo L.,McMahon, Brandon W.,Pfeil, Mark,Boatz, Jerry A.,Anderson, Scott L.,Son, Steven F.,Rogers, Robin D.
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supporting information; experimental part
p. 4311 - 4313
(2012/05/20)
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- Graphene and graphene oxide can "lubricate" ionic liquids based on specific surface interactions leading to improved low-temperature hypergolic performance
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Space-qualified lubricants: Graphene and graphene oxide (r-GO) can strongly improve the low-temperature performance of hypergolic ionic liquids by reduction of viscosity. Key to success is to match the graphene type to the specific ionic-liquid functionality. Copyright
- McCrary, Parker D.,Beasley, Preston A.,Alaniz, Spencer A.,Griggs, Chris S.,Frazier, Rachel M.,Rogers, Robin D.
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supporting information
p. 9784 - 9787
(2012/11/07)
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- The effect of the ionic liquid anion in the pretreatment of pine wood chips
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The effect of the anion of ionic liquids on air-dried pine (Pinus radiata) has been investigated. All ionic liquids used in this study contained the 1-butyl-3-methylimidazolium cation; the anions were trifluoromethanesulfonate, methylsulfate, dimethylphosphate, dicyanamide, chloride and acetate. Using a protocol for assessing the ability to swell small wood blocks (10 × 10 × 5 mm), it was shown that the anion has a profound impact on the ability to promote both swelling and dissolution of biomass. Time course studies showed that viscosity, temperature and water content were also important parameters influencing the swelling process. We used Kamlet-Taft parameters to quantify the solvent polarity of the ionic liquids and found that the anion basicity described by the parameter β correlated with the ability to expand and dissolve pine lignocellulose. It is shown that 1-butyl-3-methylimidazolium dicyanamide dissolves neither cellulose nor lignocellulosic material.
- Brandt, Agnieszka,Hallett, Jason P.,Leak, David J.,Murphy, Richard J.,Welton, Tom
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supporting information; experimental part
p. 672 - 679
(2010/08/22)
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- Thermodynamics of cesium complexes formation with 18-crown-6 in ionic liquids
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Thermodynamic data for cesium complexes formation with 18-crown-6 (18C6, L) [Cs(18C6)]+ in N-butyl-4-methyl-pyridinium tetrafluoroborate ([BMPy][BF4], I), in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4], II) and in 1-butyl-3-methylimidazolium dicyanamide ([BMIM][N(CN)2], III) were measured with NMR 133Cs technique at 23-50 °C. The stability of cesium complex in RTILs is estimated to be in the range between water and DMFA. Stability constants for [Cs(18C6)]+ are found to decrease as temperature is increasing. The following values for lgK(Cs+L) and ΔH(Cs+L) at 23 °C are determined: 2.6 (0.3), -47(1) kJ/mol (RTIL I); 2.8(0.3), -80(3) kJ/mol (RTIL II) and 3.03 (0.08), -47(2) kJ/mol (RTIL III). It is demonstrated that enthalpy change promotes complex formation while the corresponding change of entropy is negative and provides decomposition of [Cs(18C6)]+.
- Vendilo,Roenkkoemaeki,Hannu-Kuure,Lajunen,Asikkala,Krasovsky,Chernikova,Oksman,Lajunen,Tuomi,Popov
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experimental part
p. 223 - 230
(2012/01/02)
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- IONIC LIQUID AND METHOD FOR PRODUCING THE SAME
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A method according to the present invention is a method for producing an ionic liquid from a molten salt solution containing a molten salt constituted by combining the cation portion and the anion portion, the ionic liquid containing the molten salt as a main component, the method comprising: removing water from the molten salt solution, the step of removing the water including adding a compound in the molten salt solution, the compound being represented by General Formula (1): where at least two of R1 to R4 are a C1 to C8 alkoxy group(s), the rest of R1 to R4 are a hydrogen atom(s) or a C1 to C8 alkyl group(s). By this, it is possible to remove water from the molten salt solution regardless of whether the molten salt solution is hydrophilic or hydrophobic. The present invention provides a method of producing an ionic liquid, which method can remove water from any kind of ionic liquid economically, easily, and quickly.
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Page/Page column 18
(2010/04/24)
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- Effects of anionic structure and lithium salts addition on the dissolution of cellulose in 1-butyl-3-methylimidazolium-based ionic liquid solvent systems
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Cellulose is the most abundant biorenewable and biodegradable resource on the earth. However, the extent of its application is limited due to its inefficient dissolution in solvents. Thus, the development of new cellulose solvents continues to be an activ
- Xu, Airong,Wang, Jianji,Wang, Huiyong
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experimental part
p. 268 - 275
(2011/03/17)
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- Conductivities of binary mixtures of ionic liquids with polar solvents
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Data for the conductivity, κ, of selected binary mixtures of the ionic liquids [emim][BF4], [bmim][BF4], [bmim][PF 6], [brmm][DCA], and [hmim][BF4] with polar solvents (water, propylene carbonate, dimethyl-sulfoxide, methanol, dichloromethane) at 25 °C are reported. Additionally, mixture densities, p, were determined to convert κ into molar conductivity, A. The obtained results were fitted by appropriate interpolation formulas. Where possible, data were compared with information from the literature. Electrode polarization and sample purity, including [BF4-] hydrolysis, were considered as possible sources of errors in κ. The effect of viscosity on the accuracy of p and thus A was checked.
- Stoppa, Alexander,Hunger, Johannes,Buchner, Richard
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experimental part
p. 472 - 479
(2010/04/05)
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- Liquid Phase Behavior of Imidazolium-Based Ionic Liquids with Alcohols
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A systematic study of the impact of different characteristics of the ionic liquids (IL) and the alcohols on the liquid-liquid phase equilibrium of imidazolium-based IL and alcohols. Alcohol characteristics investigated include the effect of increasing the alkyl chain length of the alcohol (1-propanol vs. 1-butanol or 1-hexanol) and the effect of branching of the alcohol (1-butanol vs. 2-butanol or tert-butyl alcohol). An increase in the alkyl chain length of the alcohol resulted in an increase in the upper critical solution temperature (UCST), since the alcohol became more aliphatic and less able to interact with the IL through hydrogen-bonding, dipolar, and Coulombic forces. Increased branching of the alcohol did not affect the UCST but resulted in an increase in the solubility of the alcohol in the IL-rich phase, which correlates with increasing basicity of the alcohols. An increase in the length of one of the alkyl chains on the cation resulted in a decrease in the UCST, likely due to greater dispersion interactions between the alkyl chain on the cation and the chain of the alcohol. The UCST of the IL with alcohols decreased with increasing hydrogen bond strength. The effect of alkyl chain length on the cation and the choice of anion had significantly different effects on the mutual solubilities of IL with water than with alcohols.
- Crosthwaite, Jacob M.,Aki, Sudhir N. V. K.,Maginn, Edward J.,Brennecke, Joan F.
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p. 5113 - 5119
(2007/10/03)
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- Effect of temperature on the purity of product in the preparation of 1-butyl-3-methylimidazolium-based ionic liquids
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The preparation of room-temperature ionic liquids 1-butyl-3- methylimidazolium chloride, hexafluorophosphate, and dicyanamide by microwave-assisted reaction in non-solvent and solvent conditions has been studied in this contribution. A special emphasis is put on the effect of the reaction temperature on the purity of ionic liquids that was monitored by electrospray ionisation mass spectrometry and 1H NMR. The X-ray structure of 1-butyl-3-methylimidazolium chloride is presented.
- K?rkk?inen, Johanna,Asikkala, Janne,Laitinen, Risto S.,Lajunen, Marja K.
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p. 763 - 770
(2007/10/03)
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