1. Counterion effects on the mesomorphic and electrochemical properties of guanidinium salts.
- Author
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Ebert, Max, Lange, Alyna, Müller, Michael, Wuckert, Eugen, Gießelmann, Frank, Klamroth, Tillmann, Zens, Anna, Taubert, Andreas, and Laschat, Sabine
- Abstract
Ionic liquid crystals (ILCs) combine the ion mobility of ionic liquids with the order and self-assembly of thermotropic mesophases. To understand the role of the anion in ILCs, wedge-shaped arylguanidinium salts with tetradecyloxy side chains were chosen as benchmark systems and their liquid crystalline self-assembly in the bulk phase as well as their electrochemical behavior in solution were studied depending on the anion. Differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS, SAXS) experiments revealed that for spherical anions, the phase width of the hexagonal columnar mesophase increased with the anion size, while for non-spherical anions, the trends were less clear cut. Depending on the anion, the ILCs showed different stability towards electrochemical oxidation and reduction with the most stable being the PF
6 based compound. Cyclic voltammetry (CV) and density functional theory (DFT) calculations suggest a possible contribution of the guanidinium cation to the oxidation processes. [ABSTRACT FROM AUTHOR]- Published
- 2024
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