Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Experimental and computational thermochemistry of 1,4-benzodioxan and its 2-R derivatives

Matos, M. A. R., Sousa, C. C. S.[Clara C.S.], Morais, V. M. F.[Victor M.F.]
J. Chem. Thermodyn. 2008, 40, 10, 1485-1489
ABSTRACT
The standard molar energies of combustion, at T = 298.15 K, of crystalline 1,4-benzodioxan-2-carboxylic acid and 1,4-benzodioxan-2-hydroxymethyl were measured by static bomb calorimetry in an oxygen atmosphere. The standard molar enthalpies of sublimation, at T = 298.15 K, were obtained by Calvet microcalorimetry. These values were used to derive the standard molar enthalpies of formation of the compounds in the gas phase at T = 298.15 K: 1,4-benzodioxan-2-carboxylic acid (547.7 +- 3.0) kJ mol 1 and 1,4-benzodioxan-2-hydroxymethyl (374.2 +- 2.3) kJ mol 1. In addition, density functional theory calculations using the B3LYP hybrid exchange correlation energy functional with extended basis sets, 6-311G** and cc-pVTZ, have been performed for the compounds studied. We have also tested two more accurate computational procedures involving multiple levels of electron structure theory in order to get reliable estimates of the thermochemical parameters of the compounds studied. The agreement between experiment and theory gives confidence to estimate the enthalpies of formation of other 2-R derivatives of 1,4-benzodioxan (R = CH2COOH, OH, COCH3, CHO, CH3, CN, and NO2).
Compounds
# Formula Name
1 CO2 carbon dioxide
2 H2O water
3 O2 oxygen
4 C9H8O4 1,4-benzodioxan-2-carboxylic acid
5 C9H10O3 1,4-benzodioxane-2-methanol
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
  • 4
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Static calorimetry
  • 1
  • POMD
  • 5
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DSC
  • 1
  • POMD
  • 5
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 5
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Static calorimetry
  • 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