In:
Journal of The Electrochemical Society, The Electrochemical Society, Vol. 169, No. 8 ( 2022-08-01), p. 086502-
Abstract:
We describe the properties of three new aprotic ionic liquids (ILs) with irreducible cations and anions which are close relatives of the commonly used − N(CN) 2 anion, namely − N(CHO) 2 (diformylamide) and − N(CO) 2 (CH 2 ) 2 (succinimide), having p K a values which are slightly more basic than the p K a of OH − ions of aqueous solution chemistry. In addition to using the well-known N -butyl- N -methyl pyrrolidinium cation, P 14 + , we report the use of the tetrabutylammonium cation, + N[CH 3 (CH 2 ) 3 ] 4 , in forming an ionic liquid with the diformylamide anion. The formation and purity of these ILs was assessed by 1 H NMR spectroscopy. The broadband dielectric spectra for all three ionic liquids were analyzed and the glass transition temperatures ( T g ) estimated from the dielectric data matched well with those obtained from differential scanning calorimetry. The results demonstrate that pure aprotic ILs with high-p K a equivalent anions can be obtained by metathesis reactions despite their low p K a difference of 2 to 3. By contrast, protic analogues of these cation-anion pairs would fail to produce ILs, for which larger p K a differences are required. These new aprotic ILs are glass-forming with T g ’s near 210 K and show DC-conductivities near 0.1 mS cm −1 at ambient temperatures.
Type of Medium:
Online Resource
ISSN:
0013-4651
,
1945-7111
DOI:
10.1149/1945-7111/ac8772
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2022
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