In this work, the 1,2,5-trimethylpyrrole was investigated by combining experimental (static bomb combustion calorimetry and high temperature Calvet microcalorimetry) and computational thermochemical (standard ab initio molecular calculations) results. The experimental value obtained for its standard (p = 0.1 MPa) molar enthalpy of formation, in the gaseous phase, DfHo m ogP = (34.6 +- 2.6) kJ mol 1, at T = 298.15 K, is in excellent agreement with the estimated data obtained at the G3(MP2)//B3LYP level using a set of gas-phase working reactions. Thereby, these calculations were further extended to estimate the gas-phase enthalpies of formation of all the di-, tri-, tetra- and pentamethylpyrrole derivatives, whose experimental value is not known. Moreover, a new value for the gas-phase molar enthalpy of formation of 2,5-dimethylfuran, as 120.2 kJ mol 1, determined with the G3(MP2)//B3LYP composite approach, is suggested.
Compounds
#
Formula
Name
1
CO2
carbon dioxide
2
N2
nitrogen
3
H2O
water
4
O2
oxygen
5
C7H11N
1,2,5-trimethylpyrrole
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
5
Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid
Temperature, K; Liquid
Liquid
Gas
Static calorimetry
1
RXND
5
1
2
3
4
Specific internal energy of reaction at constant volume, J/g