Ionic liquid
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Bmim.svg/220px-Bmim.svg.png)
![](http://upload.wikimedia.org/wikipedia/commons/4/48/Hardware-accelerated-molecular-modeling.png)
An ionic liquid (IL) is a salt in the liquid state at ambient conditions. In some contexts, the term has been restricted to salts whose melting point is below a specific temperature, such as 100 °C (212 °F).[1] While ordinary liquids such as water and gasoline are predominantly made of electrically neutral molecules, ionic liquids are largely made of ions. These substances are variously called liquid electrolytes, ionic melts, ionic fluids, fused salts, liquid salts, or ionic glasses.[2][3][4]
Ionic liquids have many potential applications.[5][6] They are powerful solvents and can be used as electrolytes. Salts that are liquid at near-ambient temperature are important for electric battery applications, and have been considered as sealants due to their very low vapor pressure.
Any salt that melts without decomposing or vaporizing usually yields an ionic liquid. Sodium chloride (NaCl), for example, melts at 801 °C (1,474 °F) into a liquid that consists largely of sodium cations (Na+
) and chloride anions (Cl−
). Conversely, when an ionic liquid is cooled, it often forms an ionic solid—which may be either crystalline or glassy.
The ionic bond is usually stronger than the Van der Waals forces between the molecules of ordinary liquids. Because of these strong interactions, salts tend to have high lattice energies, manifested in high melting points. Some salts, especially those with organic cations, have low lattice energies and thus are liquid at or below room temperature. Examples include compounds based on the 1-ethyl-3-methylimidazolium (EMIM) cation and include: EMIM:Cl, EMIMAc (acetate anion), EMIM dicyanamide, (C
2H
5)(CH
3)C
3H
3N+
2·N(CN)−
2, that melts at −21 °C (−6 °F);[7] and 1-butyl-3,5-dimethylpyridinium bromide which becomes a glass below −24 °C (−11 °F).[8]
Low-temperature ionic liquids can be compared to ionic solutions, liquids that contain both ions and neutral molecules, and in particular to the so-called deep eutectic solvents, mixtures of ionic and non-ionic solid substances which have much lower melting points than the pure compounds. Certain mixtures of nitrate salts can have melting points below 100 °C.[9]
History
The term "ionic liquid" in the general sense was used as early as 1943.[10]
The discovery date of the "first" ionic liquid is disputed, along with the identity of its discoverer. Ethanolammonium nitrate (m.p. 52–55 °C) was reported in 1888 by S. Gabriel and J. Weiner.[11] In 1911 Ray and Rakshit, during preparation of the nitrite salts of ethylamine, dimethylamine, and trimethylamine observed that the reaction between ethylamine hydrochloride and silver nitrate yielded an unstable ethylammonium nitrite (C
2H
5)NH+
3·NO−
2 , a heavy yellow liquid which on immersion in a mixture of salt and ice could not be solidified and was probably the first report of room-temperature ionic liquid.[12][13] Later in 1914, Paul Walden reported one of the first stable room-temperature ionic liquids ethylammonium nitrate (C
2H
5)NH+
3·NO−
3 (m.p. 12 °C).[14] In the 1970s and 1980s, ionic liquids based on alkyl-substituted imidazolium and pyridinium cations, with halide or tetrahalogenoaluminate anions, were developed as potential electrolytes in batteries.[15][16]
For the imidazolium halogenoaluminate salts, their physical properties—such as viscosity, melting point, and acidity—could be adjusted by changing the alkyl substituents and the imidazolium/pyridinium and halide/halogenoaluminate ratios.[17] Two major drawbacks for some applications were moisture sensitivity and acidity or basicity. In 1992, Wilkes and Zawarotko obtained ionic liquids with 'neutral' weakly coordinating anions such as hexafluorophosphate (PF−
6) and tetrafluoroborate (BF−
4), allowing a much wider range of applications.[18]
Characteristics
ILs are typically colorless viscous liquids.[19] They are often moderate to poor conductors of electricity, and rarely self-ionize.[citation needed] They do, however, have a very large electrochemical window, enabling electrochemical refinement of otherwise intractable ores.[19]
They exhibit low vapor pressure, which can be as low as 10−10 Pa.[20] Many have low combustibility and are thermally stable.
The solubility properties of ILs are diverse. Saturated aliphatic compounds are generally only sparingly soluble in ionic liquids, whereas alkenes show somewhat greater solubility, and aldehydes often completely miscible. Solubility differences can be exploited in biphasic catalysis, such as hydrogenation and hydrocarbonylation processes, allowing for relatively easy separation of products and/or unreacted substrate(s). Gas solubility follows the same trend, with carbon dioxide gas showing good solubility in many ionic liquids. Carbon monoxide is less soluble in ionic liquids than in many popular organic solvents, and hydrogen is only slightly soluble (similar to the solubility in water) and may vary relatively little between the more common ionic liquids. Many classes of chemical reactions, The miscibility of ionic liquids with water or organic solvents varies with side chain lengths on the cation and with choice of anion. They can be functionalized to act as acids, bases, or ligands, and are precursors salts in the preparation of stable carbenes. Because of their distinctive properties, ionic liquids have been investigated for many applications.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Commonly_used_cations.png/220px-Commonly_used_cations.png)
Some ionic liquids can be distilled under vacuum conditions at temperatures near 300 °C.[21] The vapor is not made up of separated ions,[22] but consists of ion pairs.[23]
ILs have a wide liquid range. Some ILs do not freeze down to very low temperatures (even −150 °C), The glass transition temperature was detected below −100 °C in the case of N-methyl-N-alkylpyrrolidinium cations fluorosulfonyl-trifluoromethanesulfonylimide (FTFSI).[24] Low-temperature ionic liquids (below 130 K) have been proposed as the fluid base for an extremely large diameter spinning liquid-mirror telescope to be based on the Moon.[25]
Water is a common impurity in ionic liquids, as it can be absorbed from the atmosphere and influences the transport properties of RTILs, even at relatively low concentrations.[4]
Varieties
Classically, ILs consist of salts of unsymmetrical, flexible organic cations with symmetrical weakly coordinating anions. Both cationic and anionic components have been widely varied.[4]
Cations
Room-temperature ionic liquids (RTILs) are dominated by salts derived from 1-methylimidazole, i.e., 1-alkyl-3-methylimidazolium. Examples include 1-ethyl-3-methyl- (EMIM), 1-butyl-3-methyl- (BMIM), 1-octyl-3 methyl (OMIM), 1-decyl-3-methyl-(DMIM), 1-dodecyl-3-methyl- (dodecylMIM). Other imidazolium cations are 1-butyl-2,3-dimethylimidazolium (BMMIM or DBMIM) and 1,3-di(N,N-dimethylaminoethyl)-2-methylimidazolium (DAMI). Other N-heterocyclic cations are derived from pyridine: 4-methyl-N-butyl-pyridinium (MBPy) and N-octylpyridinium (C8Py). Conventional quaternary ammonium cations also form ILs, e.g. tetraethylammonium (TEA) and tetrabutylammonium (TBA).
Anions
Typical anions in ionic liquids include the following: tetrafluoroborate (BF4), hexafluorophosphate (PF6), bis-trifluoromethanesulfonimide (NTf2), trifluoromethanesulfonate (OTf), dicyanamide (N(CN)2), hydrogensulfate (HSO−4), and ethyl sulfate (EtOSO3). Magnetic ionic liquids can be synthesized by incorporating paramagnetic anions, illustrated by 1-butyl-3-methylimidazolium tetrachloroferrate.
Specialized ILs
Protic ionic liquids are formed via a proton transfer from an acid to a base.[26] In contrast to other ionic liquids, which generally are formed through a sequence of synthesis steps,[2] protic ionic liquids can be created more easily by simply mixing the acid and base.[26]
Phosphonium cations (R4P+) are less common but offer some advantageous properties.[27][28][29] Some examples of phosphonium cations are trihexyl(tetradecyl)phosphonium (P6,6,6,14) and tributyl(tetradecyl)phosphonium (P4,4,4,14).
Poly(ionic liquid)s
Polymerized ionic liquids, poly(ionic liquid)s or polymeric ionic liquids, all abbreviated as PIL is the polymeric form of ionic liquids.[30] They have half of the ionicity of ionic liquids since one ion is fixed as the polymer moiety to form a polymeric chain. PILs have a similar range of applications, comparable with those of ionic liquids but the polymer architecture provides a better chance for controlling the ionic conductivity. They have extended the applications of ionic liquids for designing smart materials or solid electrolytes.[31][32]
Commercial applications
Many applications have been considered, but few have been commercialized.[33][34] ILs are used in the production of gasoline by catalyzing alkylation.[35][36]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/2%2C4-Me2pentaneRoute.png/290px-2%2C4-Me2pentaneRoute.png)
An IL based on tetraalkylphosphonium iodide is a solvent for tributyltin iodide, which functions as a catalyst to rearrange the monoepoxide of butadiene. This process was commercialized as a route to 2,5-dihydrofuran, but later discontinued.[37]
Potential applications
Catalysis
ILs improve the catalytic performance of palladium nanoparticles.[38] Furthermore, ionic liquids can be used as pre-catalysts for chemical transformations. In this regard dialkylimidazoliums such as [EMIM]Ac have been used in the combination with a base to generate N-heterocyclic carbenes (NHCs). These imidazolium based NHCs are known to catalyse a number transformations such as the benzoin condensation and the OTHO reaction.[39]
Pharmaceuticals
Recognizing that approximately 50% of commercial pharmaceuticals are salts, ionic liquid forms of a number of pharmaceuticals have been investigated. Combining a pharmaceutically active cation with a pharmaceutically active anion leads to a Dual Active ionic liquid in which the actions of two drugs are combined.[40][41]
ILs can extract specific compounds from plants for pharmaceutical, nutritional and cosmetic applications, such as the antimalarial drug artemisinin from the plant Artemisia annua.[42]
Biopolymer processing
The dissolution of cellulose by ILs has attracted interest.[43] A patent application from 1930 showed that 1-alkylpyridinium chlorides dissolve cellulose.[44] Following in the footsteps of the lyocell process, which uses hydrated N-methylmorpholine N-oxide as a solvent for pulp and paper. The "valorization" of cellulose, i.e. its conversion to more valuable chemicals, has been achieved by the use of ionic liquids. Representative products are glucose esters, sorbitol, and alkylgycosides.[45] IL 1-butyl-3-methylimidazolium chloride dissolves freeze-dried banana pulp and with an additional 15% dimethyl sulfoxide, lends itself to carbon-13 NMR analysis. In this way the entire complex of starch, sucrose, glucose, and fructose can be monitored as a function of banana ripening.[46][47]
Beyond cellulose, ILs have also shown potential in the dissolution, extraction, purification, processing and modification of other biopolymers such as chitin/chitosan, starch, alginate, collagen, gelatin, keratin, and fibroin.[48][49] For example, ILs allow for the preparation of biopolymer materials in different forms (e.g. sponges, films, microparticles, nanoparticles, and aerogels) and better biopolymer chemical reactions, leading to biopolymer-based drug/gene-delivery carriers.[49] Moreover, ILs enable the synthesis of chemically modified starches with high efficiency and degrees of substitution (DS) and the development of various starch-based materials such as thermoplastic starch, composite films, solid polymer electrolytes, nanoparticles and drug carriers.[50]
Nuclear fuel reprocessing
The IL 1-butyl-3-methylimidazolium chloride has been investigated for the recovery of uranium and other metals from spent nuclear fuel and other sources.[51]
Solar thermal energy
ILs are potential heat transfer and storage media in solar thermal energy systems. Concentrating solar thermal facilities such as parabolic troughs and solar power towers focus the sun's energy onto a receiver, which can generate temperatures of around 600 °C (1,112 °F). This heat can then generate electricity in a steam or other cycle. For buffering during cloudy periods or to enable generation overnight, energy can be stored by heating an intermediate fluid. Although nitrate salts have been the medium of choice since the early 1980s, they freeze at 220 °C (428 °F) and thus require heating to prevent solidification. Ionic liquids such as [C4mim][BF
4] have more favorable liquid-phase temperature ranges (-75 to 459 °C) and could therefore be excellent liquid thermal storage media and heat transfer fluids.[52]
Waste recycling
ILs can aid the recycling of synthetic goods, plastics, and metals. They offer the specificity required to separate similar compounds from each other, such as separating polymers in plastic waste streams. This has been achieved using lower temperature extraction processes than current approaches[53] and could help avoid incinerating plastics or dumping them in landfill.
Batteries
ILs can replace water as the electrolyte in metal-air batteries. ILs are attractive because of their low vapor pressure. Furthermore, ILs have an electrochemical window of up to six volts[54] (versus 1.23 for water) supporting more energy-dense metals. Energy densities from 900 to 1600 watt-hours per kilogram appear possible.[55]
Dispersing agent
ILs can act as dispersing agents in paints to enhance finish, appearance, and drying properties.[56] ILs are used for dispersing nanomaterials at IOLITEC.
Carbon capture
ILs and amines have been investigated for capturing carbon dioxide CO
2 and purifying natural gas.[57][58][59]
Tribology
Some ionic liquids have been shown to reduce friction and wear in basic tribological testing,[60][61][62][63] and their polar nature makes them candidate lubricants for tribotronic applications. While the comparatively high cost of ionic liquids currently prevents their use as neat lubricants, adding ionic liquids in concentrations as low as 0.5 wt% may significantly alter the lubricating performance of conventional base oils. Thus, the current focus of research is on using ionic liquids as additives to lubricating oils, often with the motivation to replace widely used, ecologically harmful lubricant additives. However, the claimed ecological advantage of ionic liquids has been questioned repeatedly and is yet to be demonstrated from a life-cycle perspective.[64]
Safety
Ionic liquids' low volatility effectively eliminates a major pathway for environmental release and contamination.
Ionic liquids' aquatic toxicity is as severe as or more so than many current solvents.[65][66][67]
Ultrasound can degrade solutions of imidazolium-based ionic liquids with hydrogen peroxide and acetic acid to relatively innocuous compounds.[68]
Despite low vapor pressure many ionic liquids are combustible.[69][70]
When Tawny crazy ants (Nylanderia fulva) combat fire ants (Solenopsis invicta), the latter spray them with a toxic, lipophilic, alkaloid-based venom. The Tawny crazy ant then exudes its own venom, formic acid, and self-grooms with it, an action which de-toxifies the fire ant venom. The mixed venoms chemically react with one another to form an ionic liquid, the first naturally occurring IL to be described.[71]
See also
- 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6) for an often encountered ionic liquid
- Ionic liquids in carbon capture
- Ion gel
- Ioliomics, or studies of ions in liquids
- MDynaMix software for ionic liquids simulations
- Molten salt
- nanoFlowcell which uses ionic liquid in its car batteries
- Trioctylmethylammonium bis(trifluoromethylsulfonyl)imide
Further reading
- Hayes, Robert; Warr, Gregory G.; Atkin, Rob (2015). "Structure and Nanostructure in Ionic Liquids". Chemical Reviews. 115 (13): 6357–6426. doi:10.1021/cr500411q. PMID 26028184.
References
- ^ Wilkes, John S. (2002). "A Short History of Ionic Liquids—from Molten Salts to Neoteric Solvents". Green Chemistry. 4 (2): 73–80. doi:10.1039/b110838g.
- ^ a b Thomas Welton (1999). "Room-Temperature Ionic Liquids" (PDF). Chem. Rev. 99 (8): 2071–2084. doi:10.1021/cr980032t. PMID 11849019.
- ^ Freemantle, Michael (2009). An Introduction to Ionic Liquids. Royal Society of Chemistry. ISBN 978-1-84755-161-0.
- ^ a b c MacFarlane, Douglas; Kar, Mega; Pringle, Jennifer M. (2017). Fundamentals of ionic liquids : from chemistry to applications. Weinheim, Germany: Wiley-VCH. ISBN 9783527340033.
{{cite book}}
: CS1 maint: multiple names: authors list (link) - ^ Shiflett, Mark (2020). Commercial Applications of Ionic Liquids. Green Chemistry and Sustainable Technology. Cham: Springer. doi:10.1007/978-3-030-35245-5. ISBN 978-3-030-35244-8. S2CID 211088946.
- ^ Greer, Adam; Jacquemin, Johan; Hardacre, Christopher (2020). "Industrial Applications of Ionic Liquids". Molecules. 25 (21): 5207. doi:10.3390/molecules25215207. PMC 7664896. PMID 33182328.
- ^ D. R. MacFarlane; J. Golding; S. Forsyth; M. Forsyth & G. B. Deacon (2001). "Low viscosity ionic liquids based on organic salts of the dicyanamide anion". Chem. Commun. (16): 1430–1431. doi:10.1039/b103064g.
- ^ J. M. Crosthwaite; M. J. Muldoon; J. K. Dixon; J. L. Anderson & J. F. Brennecke (2005). "Phase transition and decomposition temperatures, heat capacities and viscosities of pyridinium ionic liquids". J. Chem. Thermodyn. 37 (6): 559–568. doi:10.1016/j.jct.2005.03.013.
- ^ Mixture of nitrate salts with m.p. below 100 deg C
- ^ R. M. Barrer (1943). "The Viscosity of Pure Liquids. II. Polymerised Ionic Melts". Trans. Faraday Soc. 39: 59–67. doi:10.1039/tf9433900059.
- ^ S. Gabriel; J. Weiner (1888). "Ueber einige Abkömmlinge des Propylamins". Chemische Berichte. 21 (2): 2669–2679. doi:10.1002/cber.18880210288. Archived from the original on 2020-02-07. Retrieved 2019-07-06.
- ^ Rây, Prafulla Chandra; Rakshit, Jitendra Nath (1911). "CLXVII.—Nitrites of the alkylammonium bases: ethylammonium nitrite, dimethylammonium nitrite, and trimethylammonium nitrite". J. Chem. Soc., Trans. 99: 1470–1475. doi:10.1039/CT9119901470. ISSN 0368-1645.
- ^ Tanner, Eden E. L. (July 2022). "Ionic liquids charge ahead". Nature Chemistry. 14 (7): 842. Bibcode:2022NatCh..14..842T. doi:10.1038/s41557-022-00975-4. ISSN 1755-4349. PMID 35778557. S2CID 250181516.
- ^ Paul Walden (1914), Bull. Acad. Sci. St. Petersburg, pages 405-422.
- ^ H. L. Chum; V. R. Koch; L. L. Miller; R. A. Osteryoung (1975). "Electrochemical scrutiny of organometallic iron complexes and hexamethylbenzene in a room-temperature molten salt". J. Am. Chem. Soc. 97 (11): 3264–3265. doi:10.1021/ja00844a081.
- ^ J. S. Wilkes; J. A. Levisky; R. A. Wilson; C. L. Hussey (1982). "Dialkylimidazolium chloroaluminate melts: a new class of room-temperature ionic liquids for electrochemistry, spectroscopy and synthesis". Inorg. Chem. 21 (3): 1263–1264. doi:10.1021/ic00133a078.
- ^ R. J. Gale; R. A. Osteryoung (1979). "Potentiometric investigation of dialuminium heptachloride formation in aluminum chloride-1-butylpyridinium chloride mixtures". Inorganic Chemistry. 18 (6): 1603–1605. doi:10.1021/ic50196a044.
- ^ J. S. Wilkes; M. J. Zaworotko (1992). "Air and water stable 1-ethyl-3-methylimidazolium based ionic liquids". Chemical Communications (13): 965–967. doi:10.1039/c39920000965.
- ^ a b "Ionic liquids". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 550–551. doi:10.1002/14356007.l14_l01. ISBN 978-3527306732.
- ^ Yauheni U. Paulechka; Gennady J. Kabo; Andrey V. Blokhin; Oleg A. Vydrov; Joseph W. Magee & Michael Frenkel (2002). "Thermodynamic Properties of 1-Butyl-3-methylimidazolium Hexafluorophosphate in the Ideal Gas State". Journal of Chemical & Engineering Data. 48 (3): 457–62. doi:10.1021/je025591i.
- ^ Martyn J. Earle; José M.S.S. Esperança; Manuela A. Gilea; José N. Canongia Lopes; Luís P.N. Rebelo; Joseph W. Magee; Kenneth R. Seddon & Jason A. Widegren (2006). "The distillation and volatility of ionic liquids". Nature. 439 (7078): 831–4. Bibcode:2006Natur.439..831E. doi:10.1038/nature04451. PMID 16482154. S2CID 4357175.
- ^ Peter Wasserscheid (2006). "Volatile times for ionic liquids". Nature. 439 (7078): 797. Bibcode:2006Natur.439..797W. doi:10.1038/439797a. PMID 16482141.
- ^ James P. Armstrong; Christopher Hurst; Robert G. Jones; Peter Licence; Kevin R. J. Lovelock; Christopher J. Satterley & Ignacio J. Villar-Garcia (2007). "Vapourisation of ionic liquids". Physical Chemistry Chemical Physics. 9 (8): 982–90. Bibcode:2007PCCP....9..982A. doi:10.1039/b615137j. PMID 17301888.
- ^ Reiter, Jakub (2 Sep 2012). "Fluorosulfonyl-(trifluoromethanesulfonyl)imide ionic liquids with enhanced asymmetry". Physical Chemistry Chemical Physics. 15 (7): 2565–2571. Bibcode:2013PCCP...15.2565R. doi:10.1039/c2cp43066e. PMID 23302957.
- ^ E. F. Borra; O. Seddiki; R. Angel; D. Eisenstein; P. Hickson; K. R. Seddon & S. P. Worden (2007). "Deposition of metal films on an ionic liquid as a basis for a lunar telescope". Nature. 447 (7147): 979–981. Bibcode:2007Natur.447..979B. doi:10.1038/nature05909. PMID 17581579. S2CID 1977373.
- ^ a b Greaves, Tamar L.; Drummond, Calum J. (2008-01-01). "Protic Ionic Liquids: Properties and Applications". Chemical Reviews. 108 (1): 206–237. doi:10.1021/cr068040u. ISSN 0009-2665. PMID 18095716.
- ^ K. J. Fraser; D. R. MacFarlane (2009). "Phosphonium-Based Ionic Liquids: An Overview". Aust. J. Chem. 62 (4): 309–321. doi:10.1071/ch08558.
- ^ Jiangshui Luo; Olaf Conrad & Ivo F. J. Vankelecom (2012). "Physicochemical properties of phosphonium-based and ammonium-based protic ionic liquids" (PDF). Journal of Materials Chemistry. 22 (38): 20574–20579. doi:10.1039/C2JM34359B. Archived (PDF) from the original on 2017-09-22. Retrieved 2018-05-16.
- ^ Tripathi, Alok Kumar (2021). "Ionic liquid–based solid electrolytes (ionogels) for application in rechargeable lithium battery". Materials Today Energy. 20: 100643. doi:10.1016/j.mtener.2021.100643. S2CID 233581904.
- ^ A. Eftekhari; O. Seddiki (2017). "Synthesis and Properties of Polymerized Ionic Liquids". European Polymer Journal. 90: 245–272. doi:10.1016/j.eurpolymj.2017.03.033.
- ^ Ionic Liquid Devices, Editor: Ali Eftekhari, Royal Society of Chemistry, Cambridge 2018, https://pubs.rsc.org/en/content/ebook/978-1-78801-183-9 Archived 2019-03-30 at the Wayback Machine
- ^ Polymerized Ionic Liquids, Editor: Ali Eftekhari, Royal Society of Chemistry, Cambridge 2018, https://pubs.rsc.org/en/content/ebook/978-1-78801-053-5 Archived 2019-03-30 at the Wayback Machine
- ^ Shiflett, Mark B., ed. (2020). Commercial Applications of Ionic Liquids. Springer International. ISBN 978-3-030-35245-5.
- ^ Plechkova, Natalia V.; Seddon, Kenneth R. (2008). "Applications of ionic liquids in the chemical industry". Chem. Soc. Rev. 37 (1): 123–150. doi:10.1039/b006677j. PMID 18197338.
- ^ Kore, Rajkumar; Scurto, Aaron M.; Shiflett, Mark B. (2020). "Review of Isobutane Alkylation Technology Using Ionic Liquid-Based Catalysts—Where Do We Stand?". Industrial & Engineering Chemistry Research. 59 (36): 15811–15838. doi:10.1021/acs.iecr.0c03418. S2CID 225512999.
- ^ "Ionic liquid alkylation technology receives award". Oil and Gas Engineering. January 2, 2018. Archived from the original on January 25, 2022. Retrieved June 10, 2021.
- ^ Meindersma, G. Wytze; Maase, Matthias; De Haan, André B. (2007). "Ionic Liquids". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.l14_l01. ISBN 978-3527306732.
- ^ Zhao, D.; Fei, Z.; Geldbach, T. J.; Scopelliti, R.; Dyson, P. J. (2004). "Nitrile-Functionalized Pyridinium Ionic Liquids: Synthesis, Characterization, and Their Application in Carbon-Carbon Coupling Reactions". J. Am. Chem. Soc. 126 (48): 15876–82. doi:10.1021/ja0463482. PMID 15571412.
- ^ L.Ta; A. Axelsson; J. Bilj; M. Haukka; H. Sundén (2014). "Ionic Liquids as Precatalysts in the Highly Stereoselective Conjugate Addition of α,β‐Unsaturated Aldehydes to Chalcones" (PDF). Chemistry: A European Journal. 20 (43): 13889–13893. doi:10.1002/chem.201404288. PMID 25201607. Archived (PDF) from the original on 2021-09-30. Retrieved 2021-03-16.
- ^ J. Stoimenovski; D. R. MacFarlane; K. Bica; R. D. Rogers (2010). "Crystalline vs. Ionic Liquid Salt Forms of Active Pharmaceutical Ingredients: A Position Paper". Pharmaceutical Research. 27 (4): 521–526. doi:10.1007/s11095-009-0030-0. PMID 20143257. S2CID 207224631.
- ^ Frank Postleb; Danuta Stefanik; Harald Seifert & Ralf Giernoth (2013). "BIOnic Liquids: Imidazolium-based Ionic Liquids with Antimicrobial Activity". Zeitschrift für Naturforschung B. 68b (10): 1123–1128. doi:10.5560/ZNB.2013-3150.
- ^ A. Lapkin; P. K. Plucinski; M. Cutler (2006). "Comparative assessment of technologies for extraction of artemisinin". Journal of Natural Products. 69 (11): 1653–1664. doi:10.1021/np060375j. PMID 17125242.
- ^ Richard P. Swatloski; Scott K. Spear; John D. Holbrey & Robin D. Rogers (2002). "Dissolution of Cellose with Ionic Liquids". Journal of the American Chemical Society. 124/18 (18): 4974–4975. CiteSeerX 10.1.1.466.7265. doi:10.1021/ja025790m. PMID 11982358. S2CID 2648188.
- ^ Charles Graenacher, Manufacture and Application of New Cellulose Solutions and Cellulose Derivatives Produced therefrom, US 1934/1943176.
- ^ Ignatyev, Igor; Charlie Van Doorslaer; Pascal G.N. Mertens; Koen Binnemans; Dirk. E. de Vos (2011). "Synthesis of glucose esters from cellulose in ionic liquids". Holzforschung. 66 (4): 417–425. doi:10.1515/hf.2011.161. S2CID 101737591. Archived from the original on 2017-08-30. Retrieved 2021-05-13.
- ^ Fort D.A, Swatloski R.P., Moyna P., Rogers R.D., Moyna G. (2006). "Use of ionic liquids in the study of fruit ripening by high-resolution 13C NMR spectroscopy: 'green' solvents meet green bananas". Chem. Commun. 2006 (7): 714–716. doi:10.1039/B515177P. PMID 16465316.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ R. E. Teixeira (2012). "Energy-efficient extraction of fuel and chemical feedstocks from algae". Green Chemistry. 14 (2): 419–427. doi:10.1039/C2GC16225C.
- ^ Mahmood, Hamayoun; Moniruzzaman, Muhammad (2019). "Recent Advances of Using Ionic Liquids for Biopolymer Extraction and Processing". Biotechnology Journal. 14 (12): 1900072. doi:10.1002/biot.201900072. ISSN 1860-7314. PMID 31677240. S2CID 207833124. Archived from the original on 2021-01-22. Retrieved 2021-01-17.
- ^ a b Chen, Jin; Xie, Fengwei; Li, Xiaoxi; Chen, Ling (2018-09-17). "Ionic liquids for the preparation of biopolymer materials for drug/gene delivery: a review". Green Chemistry. 20 (18): 4169–4200. doi:10.1039/C8GC01120F. ISSN 1463-9270. S2CID 106290272. Archived from the original on 2021-01-22. Retrieved 2021-01-17.
- ^ Ren, Fei; Wang, Jinwei; Xie, Fengwei; Zan, Ke; Wang, Shuo; Wang, Shujun (2020-04-06). "Applications of ionic liquids in starch chemistry: a review". Green Chemistry. 22 (7): 2162–2183. doi:10.1039/C9GC03738A. ISSN 1463-9270. S2CID 213702088. Archived from the original on 2021-01-24. Retrieved 2021-01-17.
- ^ Ch. Jagadeeswara Rao, K.A. Venkatesan, K. Nagarajan, T.G. Srinivasan and P. R. Vasudeva Rao, Electrodeposition of metallic uranium at near ambient conditions from room-temperature ionic liquid, Journal of Nuclear Materials, 408 (2011) 25–29.
- ^ Banqui Wu; Ramana G. Reddy & Robin D. Rogers (2001). "Novel ionic liquid thermal storage for solar thermal electric power systems". International Solar Energy Conference: 445–451.
- ^ [1] Archived March 12, 2009, at the Wayback Machine
- ^ Michel Armand; Frank Endres; Douglas R. MacFarlane; Hiroyuki Ohno & Bruno Scrosati (2009). "Ionic-liquid materials for the electrochemical challenges of the future". Nature Materials. 8 (8): 621–629. Bibcode:2009NatMa...8..621A. doi:10.1038/nmat2448. PMID 19629083.
- ^ "Betting on a Metal-Air Battery Breakthrough". Technology Review. November 5, 2009. Archived from the original on November 6, 2009. Retrieved November 7, 2009.
- ^ Examples are the TEGO brand dispersers by Evonik, used in their Pliolite brand paints.
- ^ "C&E News". Archived from the original on 2016-01-09. Retrieved 2009-08-01.
- ^ Barghi S.H.; Adibi M.; Rashtchian D. (2010). "An experimental study on permeability, diffusivity, and selectivity of CO2 and CH4 through [bmim][PF6] ionic liquid supported on an alumina membrane: Investigation of temperature fluctuations effects". Journal of Membrane Science. 362 (1–2): 346–352. doi:10.1016/j.memsci.2010.06.047.
- ^ Mota-Martinez M. T.; Althuluth M.; Berrouk A.; Kroon M.C.; Peters Cor J. (2014). "High pressure phase equilibria of binary mixtures of light hydrocarbons in the ionic liquid 1-hexyl-3-methylimidazolium tetracyanoborate". Fluid Phase Equilibria. 362: 96–101. doi:10.1016/j.fluid.2013.09.015.
- ^ Bermúdez, María-Dolores; Jiménez, Ana-Eva; Sanes, José; Carrión, Francisco-José (2009-08-04). "Ionic Liquids as Advanced Lubricant Fluids". Molecules. 14 (8): 2888–2908. doi:10.3390/molecules14082888. PMC 6255031. PMID 19701132.
- ^ Minami, Ichiro (2009-06-24). "Ionic Liquids in Tribology". Molecules. 14 (6): 2286–2305. doi:10.3390/molecules14062286. PMC 6254448. PMID 19553900.
- ^ Somers, Anthony E.; Howlett, Patrick C.; MacFarlane, Douglas R.; Forsyth, Maria (2013-01-21). "A Review of Ionic Liquid Lubricants" (PDF). Lubricants. 1 (1): 3–21. doi:10.3390/lubricants1010003. Archived (PDF) from the original on 2018-11-04. Retrieved 2019-08-16.
- ^ Zhou, Feng; Liang, Yongmin; Liu, Weimin (2009-08-19). "Ionic liquid lubricants: designed chemistry for engineering applications". Chemical Society Reviews. 38 (9): 2590–9. doi:10.1039/b817899m. ISSN 1460-4744. PMID 19690739.
- ^ Petkovic, Marija; Seddon, Kenneth R.; Rebelo, Luís Paulo N.; Pereira, Cristina Silva (2011-02-22). "Ionic liquids: a pathway to environmental acceptability". Chem. Soc. Rev. 40 (3): 1383–1403. doi:10.1039/c004968a. ISSN 1460-4744. PMID 21116514.
- ^ C Pretti; C Chiappe; D Pieraccini; M Gregori; F Abramo; G Monni & L Intorre (2006). "Acute toxicity of ionic liquids to the zebrafish (Danio rerio)". Green Chem. 8 (3): 238–240. doi:10.1039/b511554j.
- ^ D. Zhao; Y. Liao & Z. Zhang (2007). "Toxicity of Ionic Liquids". CLEAN - Soil, Air, Water. 35 (1): 42–48. doi:10.1002/clen.200600015.
- ^ J Ranke; S Stolte; R Störmann; J Arning & B Jastorff (2007). "Design of sustainable chemical products – the example of ionic liquids". Chem. Rev. 107 (6): 2183–2206. doi:10.1021/cr050942s. PMID 17564479.
- ^ Xuehui Li; Jinggan Zhao; Qianhe Li; Lefu Wang & Shik Chi Tsang (2007). "Ultrasonic chemical oxidative degradations of 1,3-dialkylimidazolium ionic liquids and their mechanistic elucidations". Dalton Trans. (19): 1875–1880. doi:10.1039/b618384k. PMID 17702165.
- ^ Marcin Smiglak; W. Mathew Reichert; John D. Holbrey; John S. Wilkes; Luyi Sun; Joseph S. Thrasher; Kostyantyn Kirichenko; et al. (2006). "Combustible ionic liquids by design: is laboratory safety another ionic liquid myth?". Chemical Communications. 2006 (24): 2554–2556. doi:10.1039/b602086k. PMID 16779475.
- ^ Uwe Schaller; Thomas Keicher; Volker Weiser; Horst Krause; Stefan Schlechtriem (2010-07-10). "Synthesis, Characterization and Combustion of Triazolium Based Salts" (PDF). pp. 1–23. Archived (PDF) from the original on 2016-03-07. Retrieved 2016-03-02.
- ^ Chen, Li; Mullen, Genevieve E.; Le Roch, Myriam; Cassity, Cody G.; Gouault, Nicolas; Fadamiro, Henry Y.; Barletta, Robert E.; O'Brien, Richard A.; Sykora, Richard E.; Stenson, Alexandra C.; West, Kevin N.; Horne, Howard E.; Hendrich, Jeffrey M.; Xiang, Kang Rui; Davis, James H. (2014). "On the Formation of a Protic Ionic Liquid in Nature". Angewandte Chemie International Edition. 53 (44): 11762–11765. doi:10.1002/anie.201404402. PMID 25045040.
External links
- Ionic Liquids Biological Effects Database Archived 2021-04-21 at the Wayback Machine, free database on toxicology and ecotoxicology of ionic liquids
- Corresponding states for ionic fluids