ABSTRACT

The standard (p = 0.1 MPa) molar enthalpies of formation in the condensed state of chromanone, dihydrocoumarin, and 3-isochromanone were derived from the standard molar energies of combustion in oxygen at T = 298.15 K, measured by combustion calorimetry. Calvet microcalorimetry was used to derive the standard molar enthalpies of sublimation and vaporization.From these values the standard molar enthalpies in the gaseous phase, at T = 298.15 K, were derived. Additionally estimates were performed of the enthalpies of formation of all the studied compounds in gas-phase, using DFT and other more accurate correlated calculations, together with appropriate isodesmic or homodesmic reactions. There is a reasonable agreement between computational and experimental results.

Compounds

#	Formula	Name
1	CO2	carbon dioxide
2	H2O	water
3	O2	oxygen
4	C9H8O2	2,3-dihydro-4H-1-benzopyran-4-one
5	C9H8O2	dihydrocoumarin
6	C9H8O2	1,4-dihydro-3H-2-benzopyran-3-one

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Phase	Method	#Points
POMD	4	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	4	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	4	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	4	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	mass and volume of pellet	1
POMD	5	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	6	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	6	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	6	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	6	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	mass and volume of pellet	1
RXND	4 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	5 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	6 1 2 3	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Experimental and computational thermochemistry of the isomers: Chromanone, 3-isochromanone, and dihydrocoumarin

Matos, M. A. R.[M. Agostinha R.], Sousa, C. C. S.[Clara C. S.], Morais, V. M. F.[Victor M.F.]

ABSTRACT