Protic ionic hquids

Chapter 13 discusses the design and analysis of the microscopic features of binary solvent systems formed by room temperature ionic liquids (RTILs) with molecular solvents. For this purpose, protic ionic hquids (PILs), ethylammoiuum nitrate (FAN), and l-n-butyl-3-methylimidazolium (bmim)-based ILs and the molecular solvents such as acetonitrile, dimethyl sulfoxide, A,A-dimethylfonnamide, and protic (different alcohols) are selected. The study focuses on the identification of solvent mixtures of relevant solvating properties to propose them as new solvents. ... 

Rana UA, Forsyth M, MacFarlane DR, Pringle JM (2012) Toward protic ionic hquid and organic ionic plastic crystd electrolytes for fuel cells. Electrochim Acta 84 213-222. doi 10.1016/j.electacta.2012.03.058... 

On the other hand, protic ionic hquids (PILs) have recently attracted attention for their variable proton activities (Yoshizawa et al., 2003 Belieres AngeU, 2007 AngeU et at., 2007 Greaves Drummond, 2008). Although the first room-temp)erature ionic hquid is ethylammonimn nitrate (= EAN) which is the simplest PIL, a large part of the ILs hitherto... 

Protic impurities have to be taken into account for two groups of ionic Hquids those that have been produced by an exchange reaction involving a strong acid (often the case, for example, for [BMIM][PF ]), and those that are sensitive to hydrolysis. In the latter case, the protons may originate from the hydrolysis of the anion, forming an acid that may be dissolved in the ionic liquid. 

For ionic liquids that do not mix completely with water (and which display sufficient hydrolysis stability), there is an easy test for acidic impurities. The ionic Hquid is added to water and a pH test of the aqueous phase is carried out. If the aqueous phase is acidic, the ionic liquid should be washed with water to the point where the washing water becomes neutral. For ionic liquids that mix completely with water we recommend a standardized, highly proton-sensitive test reaction to check for protic impurities. 

Obviously, the check for protic impurities becomes crucial if the ionic Hquid is to be used for applications in which protons are known to be active compounds. For some organic reactions, one has to be sure that an ionic liquid effect does not turn out to be a protic impurity effect at some later stage of the research ... 

Sasaki, K, Nagai, H, Matsumura, S, Toshima, K, A novel greener glycosidation using an acid-ionic hquid containing a protic acid. Tetrahedron Lett., 44, 5605-5608, 2003. 

For ionic hquids with protic cations decomposition occurs most easily by proton transfer from the cation to the anion to produce the add and base from which the ionic hquid was prepared. The temperatures at which this occurs have been related to the difference in the pfC values of these parent adds and bases [25-27]. For fiiUy alkylated ionic hquids, two major decomposition... 

The dielectric constant (Cj.) of the pure hquid is by far the most commonly used polarity scale. Estimates of static dielectric constants of ionic liquids have been derived from microwave dielectric spectroscopy [93]. Most values found ranged from 9 to 15 depending upon the ionic hquid, characterizing these as nonpolar hquids. However, values in excess of 30 were found for some protic ionic liquids. 

Protic salt electrolyte concepts (i.e., ionic hquid filled PEMs, and, non-leachable PEMs),... 

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