DMA spectra of the samples [P2225][DCA] (a), [N2225][DCA] (b), [P2225][TCM] (c), and [N2225][TCM] (d), measured upon cooling at three frequencies (blue, 10 Hz; green, 5 Hz; and red, 1 Hz). The continuous thick line is a fit according to Equations (6)–(8) for the thermally activated peak.