LAUSR

Abstract An experimental fact is that the replacement of the hydrogen atom in CH3 group of ethanol by hydroxyl ( OH) or amino ( NH2) moieties, leads to an opposite change in molar volume of the formed new compounds (1,2-ethanediol and 2-aminoethanol), in comparison to the molar volume of ethanol. The paper shows, that such volumetric differentiation results from essentially different structure of the supramolecular polymers formed in these two hydrogen-bonded liquids: the chain-like shape of self-assemblies in 1,2-ethanediol allows for much denser molecular packing than the polymers of much more varied shapes existing in 2-aminoethanol or in ethanol. The conclusion results from the analysis of the temperature behavior of the static permittivity and resulting from that behavior the orientational entropy increment of studied liquids.