ABSTRACT

This paper reports the standard (0.1 MPa) molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, of 1-(2-nitrophenyl)pyrrole and of 1-(4-nitrophenyl)pyrrole as (235.7 +- 2.7) kJ mol-1 and (205.5 +- 2.5) kJ mol-1, respectively. These values were derived from experimental thermodynamic parameters, namely from the standard (0.1 MPa) molar enthalpies of formation, in the crystalline phase, at T = 298.15 K, obtained from the standard molar enthalpies of combustion, source, measured by static-bomb combustion calorimetry, and from the standard molar enthalpies of sublimation, at T = 298.15 K, determined from the temperature vapour pressure dependence, obtained by the Knudsen mass loss effusion method. Additionally, the gas-phase enthalpies of formation were estimated by G3(MP2)//B3LYP calculations, using several gas-phase working reactions, and were compared with the experimental determined ones. Experimental and theoretical results are in very good agreement and show that 1-(4-nitrophenyl)pyrrole is thermodynamically more stable than the 2-isomer. This composite approach was also used to estimate the gas-phase enthalpy of formation of the 1-(3-nitrophenyl)pyrrole.

Compounds

#	Formula	Name
1	CO2	carbon dioxide
2	N2	nitrogen
3	H2O	water
4	O2	oxygen
5	C10H8N2O2	1-(2-nitrophenyl)pyrrole
6	C10H8N2O2	1-(4-nitrophenyl)pyrrole

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	5	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Clausius-Clapeyron Equation	1
POMD	5	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Clausius-Clapeyron Equation	1
POMD	5	Vapor or sublimation pressure, kPa ; Crystal	Temperature, K; Crystal	Crystal Gas	Calculated from knudsen effusion weight loss	33
POMD	6	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Clausius-Clapeyron Equation	1
POMD	6	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Ebulliometric method (Recirculating still)	1
POMD	6	Vapor or sublimation pressure, kPa ; Crystal	Temperature, K; Crystal	Crystal Gas	Calculated from knudsen effusion weight loss	34
RXND	5 1 2 3 4	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	6 1 2 3 4	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

A joint experimental and computational investigation on the thermochemistry of (nitrophenyl)pyrroles

Santos, A. F. L. O. M.[Ana Filipa L.O.M.], Ribeiro da Silva, M. A. V.[Manuel A. V.]

ABSTRACT