Aprotic ionic liquids

This relation is shown in Figure 2.1. It has so far been found free of exceptions when base is an amine nitrogen. The protic ionic liquids as a class [16-18] are considerably more fluid than the aprotic ionic liquids [17], for reasons that are not clear at this time (see Section 2.6). 

Figure 2.8 Specific conductivities of protic vs. aprotic ionic liquids, showing matching of concentrated lithium chloride solution conductivity by solvent-free aprotic liquids. Note that at low temperature, the conductivity of protic nitrate in excess nitric acid is higher than that of the aqueous Lid case with the same excess solvent. (From Xu and Angell [17] by permission)...

Figure 20.2 Chemical structures of (a) a typical protic ionic liquid and (b) an aprotic ionic liquid. A bold H in (a) indicates an active proton.

On reversing the scan direction at 0.13 V, the reduction of Cu(II) to Cu(I) is close to an ideal one-electron reversible process. Interestingly, scanning the potential to more negative values than the rl process, but prior to the onset of the rl process, an oxidation stripping peak is detected at 0.50 V on the anodic scan. This voltammetric behavior is distinctly different from that in aprotic ionic liquids (AILs), organic solvents, or aqueous media [66-70], and is attributed to the disproportionation of Cu(I)inEAN viaEq. 13.10. 

Espinosa T, Sanes J, Jimenez AE, Bermudez MD (2013) Surface interactions, corrosion processes and lubricating performance of protic and aprotic ionic liquids with OFHC copper. Appl Surf Sci 273 578-597. doi 10.1016/j.apsusc.2013.02.083... 

Xu M, Ivey DG, Xie Z, Qu W (2013) Electrochemical behavior of Zn/Zn(Il) couples in aprotic ionic liquids based on pyrrolidinium and imidazolium cations and bis (trifluoromethanesulfonyl)imide and dicyanamide anions. Electrochim Acta 89 756-762. doi 10.1016/j.electacta.2012.11.023... 

Protic or aprotic Ionic Liquids [21]. Protic ionic liquids (PILs), as all other protic solvents can give away protons and, more important, can form hydrogen bonds. As a result, they are not necessarily fully dissociated and can be distUlated more easily (though still xmder extreme conditions) than aprotic Ionic Liquids (AlLs). Further, they are considered to be poor ILs in the sense that their electrical conductivity is lower than what is predicted by the Walden plot. FAN is a representative example of a PIL. 

ILs used in self-assembly systems can be divided in two categories protic ionic liquids (PILs, solvent properties are similar to water) and aprotic ionic liquids (AILs, largest group most of them derived from disubstituted imidazolium cations). Many surfactant ILs have thermotropic properties, forming liquid crystal phases with no additional solvent present. The solvophobic interaction between PILs and... 

Esperanqa JMSS, Lopes INC, Tariq M, Santos LMNBF, Magee JW, Rebelo LPN (2010) Volatility of aprotic ionic liquids - a review. J Chem Eng Data 55 3-12... 

Schroder B, Coutinho JAP (2014) Predicting enthalpies of vaporization of aprotic ionic liquids with COSMO-RS. Fluid Phase Equilib 370 24-33... 

Lewandowski A, WaUgora L, GaUnski M (2009) Ferrocene as a reference redox couple for aprotic ionic liquids. Electroanalysis 21(20) 2221-2227. doi 10.1002/elan.200904669... 

Shiddiky MIA, Torriero AAJ, Zhao C, Butgar 1, Kennedy G, Bond AM (2009) Nonadditivity of faradaic currents and modification of capaciteuice currents in the voltammetry of mixtures of ferrocene and the cobaltocenium cation in protic and aprotic ionic liquids. J Am Chem Soc 131 7976-7989... 

Peric B, Sierra J, Marti E, Cruanas R, Garau MA (2014) A comparative study of the terrestrial ecotoxidty of selected protic and aprotic ionic liquids. Chemosphere 108 418-425. doi 10.1016/j.chemosphere.2014.02.043... 

Femicola A, Navarra M, Panero S (2008) Aprotic ionic liquids as electrolyte components in protonic membranes. J Appl Electrochem 38(7) 993-996. doi 10.1007/sl0800-008-9514-6... 

Protic ionic liquids (PIL) composed of monoprotic alkylethylenediaminium (alkyl = hexyl and 2-ethylhexyl) cations coupled with bis(trifluoromethanesulfonyl)imide anion (= TFSA) at room temperature have been isolated. (lida et ah, 2009) It is contrast that the monoprotic hexylethylenediaminium (= HexH)TFSA salt tends to be crystallized by cooling while the monoprotic 2-ethylhexylethylenediaminium (= EtHexH)TFSA salt assumed only a glassy state in the solid state. In the liquids, the HexH salt was more fluid than the EtHexH salt. Protic ionic liquids (PILs) have recently attracted attention from a viewpoint of variable proton activities. PILs are generally more hydrophilic and dissolve metal salts to a larger extent than aprotic ionic liquids (AILs). Alkylethylene-diamines have two amines and have... 

For a better overview, the different microemulsion systems with aprotic ionic liquids, the methods used to characterize them and the corresponding references are summarized in Table 1. 

Table 1. Summary of the different microemulsions systems with aprotic ionic liquids together with the references and methods used.

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