Thermochimica Acta, Vol.544, 84-88, 2012
Enthalpies and heat capacities of interaction of tetraalkylammonium bromides with hexamethylphosphoric triamide in water, methanol and ethylene glycol: The comparative analysis of aqueous and non-aqueous systems
This paper focuses on the interaction between familiar hydrophobic solutes - tetraalkylammonium ions and hexamethylphosphoric triamide (HMFT) in water and H-bonded non-aqueous solvents such as methanol (MeOH) and ethylene glycol (C2H4(OH)(2)). Enthalpic and heat capacity parameters of electrolyte-amide and methylene group-amide pair interaction have been extracted from the enthalpies of solution for Et4NBr and Bu4NBr in the mixtures of MeOH or C2H4(OH)(2) with HMPT at 298 and 313 K and compared with those in water. We have found that for tetraalkylammonium ions of moderate size solvo-phobic interaction with apolar groups of HMPT molecule is much weaker pronounced in non-aqueous media than in water. (C) 2012 Elsevier B.V. All rights reserved.