Thermochemistry of chromone- and coumarin-3-carboxylic acid

The standard (pA(0)A = 0.1 MPa) molar enthalpies of formation in the condensed state of chromone-3-carboxylic acid and coumarin-3-carboxylic acid were derived from the standard molar energies of combustion in oxygen at T = 298.15 K, measured by combustion calorimetry. The standard molar enthalpies o...

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Bibliographic Details
Main Author: Agostinha A R Matos (author)
Other Authors: Clara C S Sousa (author), Victor M F Morais (author)
Format: article
Language:eng
Published: 2010
Subjects:
Online Access:https://hdl.handle.net/10216/101991
Country:Portugal
Oai:oai:repositorio-aberto.up.pt:10216/101991
Description
Summary:The standard (pA(0)A = 0.1 MPa) molar enthalpies of formation in the condensed state of chromone-3-carboxylic acid and coumarin-3-carboxylic acid were derived from the standard molar energies of combustion in oxygen at T = 298.15 K, measured by combustion calorimetry. The standard molar enthalpies of sublimation were obtained by Calvet microcalorimetry. From these values the standard molar enthalpies in the gaseous phase, at T = 298.15 K, were derived. Additionally estimates of the enthalpies of formation, of all the studied compounds in gas-phase, were performed using DFT and other more accurate correlated calculations (MCCM and G3MP2), together with appropriate isodesmic, homodesmic or atomization reactions. There is a reasonable agreement between computational and experimental results.