Biller H, Lerch S, Tölke K, Stammler H, Hoge B, Strassner T. Tetrakis(pentafluoroethyl)gallate, [Ga(C
2 F
5 )
4 ]
- , Ionic Liquids.
Chemistry 2021;
27:13325-13329. [PMID:
34390044 PMCID:
PMC8519063 DOI:
10.1002/chem.202102097]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Indexed: 11/23/2022]
Abstract
We synthesized new imidazolium-based tunable aryl alkyl ionic liquids (TAAILs) with the weakly coordinating tetrakis(pentafluoroethyl)gallate anion, [Ga(C2 F5 )4 ]- . Phenyl and phenyl derivatives (2-Me, 4-OMe, 2,4-F) were combined with varying alkyl chain lengths at the imidazolium core leading to TAAILs, which were investigated with regard to their viscosity, conductivity, and electrochemical window and compared to EMIM and BMIM standard cations. Remarkable low viscosities of 29 cP at 25 °C for [BMIM][Ga(C2 F5 )4 ] were achieved. However, the EMIM and BMIM gallates show electrochemical instability, releasing pentafluoroethane at a voltage of 1.5 V. The 2-Me-substituted gallate-TAAILs slowly decompose over several weeks, whereas all other gallate-TAAILs showed no decomposition at all. With electrochemical windows of up to 5.15 V and low viscosities in a range of 66-162 cP, the gallate-TAAILs are promising candidates as electrolytes in electrochemical applications.
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