In this work, we have determined the experimental standard (p = 0.1 MPa) molar enthalpies of formation, in the gas phase, of 2,6-dimethyl-4-pyrone -(261.5 +- 2.6) kJ mol-1 and 2-ethyl-3-hydroxy-4-pyrone -(420.9 +- 2.8) kJ mol-1. These values were obtained by combining the standard molar enthalpy of formation in the condensed phase, derived from combustion experiments in oxygen, at T = 298.15 K, in a static bomb calorimeter, with the standard molar enthalpy of sublimation, at T = 298.15 K, obtained by Calvet microcalorimetry. Additionally, high-level density functional theory calculations using the B3LYP hybrid-exchange-correlation energy functional with extended basis sets have been performed for these two compounds. Good agreement was obtained between the experimental and computational results. Using the same methodology, we calculated the standard molar enthalpy of formation of gaseous 2-methyl-3-hydroxy-4-pyrone.
Compounds
#
Formula
Name
1
CO2
carbon dioxide
2
H2O
water
3
O2
oxygen
4
H2
hydrogen
5
C
graphite
6
C7H8O2
2,6-dimethyl-.gamma.-pyrone
7
C7H8O3
2-ethyl-3-hydroxy-4H-pyran-4-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
Constraint
Phase
Method
#Points
POMD
6
Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal
Temperature, K; Crystal
Crystal
Gas
drop microcalorimetry
1
POMD
7
Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal
Temperature, K; Crystal
Crystal
Gas
drop microcalorimetry
1
RXND
6
1
2
3
Specific internal energy of reaction at constant volume, J/g
Static bomb calorimetry
1
RXND
7
1
2
3
Specific internal energy of reaction at constant volume, J/g