The complex permittivity of ethylammonium nitrate has been measured as a function of frequency between 3 MHz and 40 GHz at eight temperatures between 288.15 and 353.15 K. The spectra are well represented by a sum of a conductivity term and a relaxation spectral function that reflects an unsymmetrical relaxation time distribution. Parameter values are given for the Cole−Davidson term and the Kohlrausch−Williams−Watts model. Molecular mechanisms in conformance with an unsymmetrical relaxation time distribution are discussed. The dominant relaxation process with a relaxation frequency in the accessible range can be explained by the formation of a small amount of dipolar ion complexes. The values for the extrapolated high-frequency permittivity indicate a further relaxation process, well above the frequency range of measurements, which is likely to reflect modes of motions of the cation and anion lattices relative to one another.

We report the frequency-dependent complex dielectric permittivity of aqueous solutions of the homologous saccharides D(+)-glucose, maltose, and maltotriose in the frequency range 200 MHz⩽ν⩽20 GHz. For each solute, solutions having concentrations between 0.01 and 1 mol dm−3 were studied. In all measured spectra two dispersion/loss regions could be discerned. With the exception of the two most concentrated maltotriose solutions, a good description of the spectra by the superposition of two Debye processes was possible. The amplitudes and correlation times of the glucose and maltose solutions determined from fits of the experimental data were compared to those obtained in an earlier molecular dynamics study of such systems; the overall agreement between experiment and simulation is quite satisfactory. A dielectric component analysis of the simulation results permitted a more detailed assignment of the relaxation processes occurring on the molecular level. The physical picture emerging from this analysis is compared with traditional hydration models used in the interpretation of measured dielectric data. It is shown that the usual standard models do not capture an important contribution arising from cross terms due to dipolar interactions between solute and water, as well as between hydration water and bulk water. This finding suggests that conventional approaches to determine molecular dipole moments of the solutes may be problematic. This is certainly the case for solutes with small molecular dipole moments, but strong solute–solvent interactions, such as the saccharides studied here.