Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Molecular energetics of pyrrolecarbonitriles and derivatives: A combined calorimetric and computational study

Santos, A. F. L. O. M.[Ana Filipa L.O.M.], da Silva, M. A. V. R.[Manuel A. V. Ribeiro]
J. Chem. Thermodyn. 2012, 48, 194-200
ABSTRACT
In this work, calorimetric measurements were carried out, in order to determine the standard (p = 0.1 MPa) molar enthalpies of formation, in the gaseous phase at T = 298.15 K, of 2-pyrrolecarbonitrile and 1,5-dimethyl-2-pyrrolecarbonitrile. These data were calculated from the standard molar enthalpies of formation, in the condensed phase at T = 298.15 K, derived from static bomb combustion calorimetry measurements, and from the standard molar enthalpies of phase transition at T = 298.15 K, obtained by high temperature Calvet microcalorimetry. The gas-phase enthalpies of formation were also calculated from high level ab initio molecular orbital calculations, at the G3(MP2)//B3LYP level, and a very good agreement between experimental and computational values was obtained, giving us support to estimate the gas-phase enthalpies of formation of 3-pyrrolecarbonitrile and 1,5-dimethyl-3-pyrrolecarbonitrile. Moreover, the molecular structure of the four molecules was established and the structural parameters were determined at the B3LYP/6-31G(d) level of theory.
Compounds
# Formula Name
1 CO2 carbon dioxide
2 N2 nitrogen
3 H2O water
4 O2 oxygen
5 H2 hydrogen
6 C graphite
7 C5H4N2 2-cyanopyrrole;
8 C7H8N2 1,5-dimethyl-2-pyrrolecarbonitrile
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
  • 7
  • Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • drop calorimetry
  • 1
  • POMD
  • 7
  • Molar enthalpy, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • Drop calorimetry
  • 1
  • POMD
  • 8
  • Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • drop calorimetry
  • 1
  • POMD
  • 8
  • Molar enthalpy, kJ/mol ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Drop calorimetry
  • 1
  • RXND
  • 7
  • 1
  • 2
  • 3
  • 4
  • Specific internal energy of reaction at constant volume, J/g
  • Static bomb calorimetry
  • 1
  • RXND
  • 8
  • 1
  • 2
  • 3
  • 4
  • Specific internal energy of reaction at constant volume, J/g
  • Static bomb calorimetry
  • 1
  • RXND
  • 7
  • 5
  • 2
  • 6
  • Molar enthalpy of reaction, kJ/mol
  • Static bomb calorimetry
  • 1
  • RXND
  • 8
  • 5
  • 2
  • 6
  • Molar enthalpy of reaction, kJ/mol
  • Static bomb calorimetry
  • 1