Estimation of sublimation enthalpies of aromatic amides at 298.15 K from the values of fusion enthalpies

Abstract

© 2016 Elsevier B.V.In this work a method for determination of sublimation enthalpies of amides substituted in aromatic ring from data on fusion enthalpies at the melting temperature was proposed. This method was checked by calculation of sublimation enthalpies of 12 substituted benzamides, containing −CH3, −OCH3, −F, −OH, −NH2 and −NO2 substituents, as well as m- and p-pyridinecarboxamides, which were compared to literature values. Sublimation enthalpies of 3-aminobenzamide, 3- and 4-nitrobenzamides at 298.15 K were determined by solution calorimetry approach and amounted to 123.9 and 124.5 kJ·mol−1, respectively. This method showed good congruence with the results of direct experiment, as well as with solution calorimetry approach. In most of the cases, divergence does not exceed 2–3%.