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00925njm 22002777a 4500 dc Hevia de los Mozos, Luis Fernando author González López, Juan Antonio Mariano author Cobos Huerga, Ana author García de la Fuente, Isaías Laudelino author Sanz del Soto, Luis Felipe author 2019 Relative permittivities at 1 MHz, epsilon(r), at 0.1 MPa and (293.15–303.15) K and refractive indices, nD, at similar conditions have been measured for the alkan-1-ol (methanol, propan-1-ol, butan-1-ol, pentan-1-ol or heptan-1-ol) + N,N-diethylethanamine (TEA) systems. Positive values of the excess permittivities, epsilon(r)E, are encountered for the methanol system at high alcohol concentrations. The remaining mixtures are characterized by negative epsilon(r)E values over the whole composition range. At fi1 (volume fraction) = 0.5, epsilon(r)E changes in the order: methanol > propan-1-ol > butan-1-ol < pentan-1-ol < heptan-1-ol. Mixtures formed by alkan-1-ol and an isomeric amine, hexan-1-amine (HxA) or N-propylpropan-1-amine (DPA) or cyclohexylamine, behave similarly. This has been explained in terms of the lower and weaker self-association of longer alkan-1-ols. From the permittivity data, it is shown that: (i) (alkan-1-ol)-TEA interactions contribute positively to epsilon(r)E; (ii) TEA is an effective breaker of the network of the alkan-1-ols; (iii) structural effects, which are very important for the volumetric and calorimetric data of alkan-1-ol + TEA systems, are also relevant when evaluating dielectric data. This is confirmed by the comparison of epsilon(r)E measurements for alkan-1-ol + aliphatic amine mixtures; (iv) the aromaticity effect (i.e., the replacement of TEA by pyridine in systems with a given alkan-1-ol) leads to an increase of the mixture polarization. Calculations conducted in the framework of the Kirkwood-Fröhlich model are consistent with the previous statements. The Journal of Chemical Thermodynamics 141 (2020) 105937 0021-9614 http://uvadoc.uva.es/handle/10324/38602 10.1016/j.jct.2019.105937 Article number 105937 February 2020 Journal of Chemical Thermodynamics 141 Termodinámica Thermodynamics of mixtures with strongly negative deviations from Raoult's law. XVII. Permittivities and refractive indices for alkan-1-ol + N,N-diethylethanamine systems at (293.15–303.15) K. Application of the Kirkwood-Fröhlich model