ABSTRACT

The standard enthalpies of formation of benzofuran-, indole-, and benzothiophene-2-carboxylic acids, and 2-acetylbenzofuran in the condensed phase were measured at T = 298.15 K from experimental determinations of their energies of combustion by isoperibolic calorimetry. The enthalpies, temperatures of melting, purities and heat capacities of the compounds were determined using differential scanning calorimetry. Using thermogravimetry the enthalpies of sublimation were obtained and subsequently, the standard enthalpies of formation in the gas-phase and at T = 298.15 K for the four compounds were derived. The results of this analysis were compared with the values obtained by the Gaussian-4 procedure using the atomization method. The computational results are in good agreement with the experimental values. The influence of the heteroatom (oxygen, nitrogen and sulfur) and acetyl or carboxyl groups on the standard enthalpy of formation is also discussed.

Compounds

#	Formula	Name
1	H2O4S	sulfuric acid
2	CO2	carbon dioxide
3	H2O	water
4	O2	oxygen
5	N2	nitrogen
6	C9H6O3	benzofuran-2-carboxylic acid
7	C9H7NO2	indole-2-carboxylic acid
8	C9H6O2S	benzo[b]thiophene-2-carboxylic acid
9	C10H8O2	2-acetylbenzofuran

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	6	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	measuring the mass and volume of a pellet	1
POMD	6	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	6	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	6	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	1
POMD	6	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	7	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	7	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	7	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	1
POMD	7	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	8	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	measuring the mass and volume of a pellet	1
POMD	8	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	8	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	8	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	1
POMD	8	Molar enthalpy of vaporization or sublimation, kJ/mol ; Crystal	Temperature, K; Crystal	Crystal Gas	Derived by Second law	1
POMD	9	Normal melting temperature, K ; Crystal		Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	9	Molar enthalpy of transition or fusion, kJ/mol ; Crystal		Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	9	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	1
POMD	9	Molar enthalpy of vaporization or sublimation, kJ/mol ; Liquid	Temperature, K; Liquid	Liquid Gas	Derived by Second law	1
RXND	8 1 2 3 4	Specific internal energy of reaction at constant volume, J/g			Rotating bomb calorimetry	1
RXND	6 2 3 4	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	7 2 5 3 4	Specific internal energy of reaction at constant volume, J/g			Static bomb calorimetry	1
RXND	9 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

Experimental and computational thermochemical study of benzofuran, benzothiophene and indole derivatives

Ramos, F.[Fernando], Flores, H.[Henoc], Rojas, A.[Aaron], Hernandez-Perez, J. M.[Julio M.], Camarillo, E. A.[E. Adriana], Amador, M. P.[M. Patricia]

ABSTRACT