| Popis: |
Ionic plastic crystals (IPCs) have been studied as solid-state proton conductors due to their properties such as non-volatility, plasticity, and high ionic conductivity. In order to further improve their proton transport property, understanding the relationship between the ion structure and the properties of IPCs is needed. For this purpose, five pyrrolidinium salts with dihydrogen phosphate anion ([DHP]−) were synthesized. 1-Ethyl-1-methylpyrrolidinium ([C1,2pyr]+) cation and 1-(2-hydroxyethyl)-1-methylpyrrolidinium ([C1,2OHpyr]+) cation exhibited one or more solid-solid phase transitions in DSC traces. The 1H and 31P solid state NMR results indicated that the component ions in [C1,2pyr][DHP] exhibited rotational mobility in Phase I. [C1,2pyr][DHP] and [C1,2OHpyr][DHP] exhibited higher ionic conductivity values than the other pyrrolidinium salts after the addition of H3PO4, and their ionic conductivity was over 10−3 S cm−1 at 120 °C. Thus, rotational mobility and the hydroxyl group on the pyrrolidinium cation will contribute to proton transport in the solid-state phases. |
