High frequency dielectric response of the ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide

A study of the room-temperature ionic liquid <i>N</i>-methyl-<i>N</i>-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.<br />