ABSTRACT

The standard molar enthalpies of combustion of 2-aminobenzothiazole (2AB), 2-amino-4-methyl-benzothiazole (2A4MB), and 2-amino-6-methyl-benzothiazole (2A6MB) were determined in the crystalline phase at T = 298.15 K using a rotating-bomb combustion calorimeter. The molar energies of combustion of these compounds were found to be: ( 4273.6 +- 0.9), ( 4896.9 +- 1.1), and ( 4906.9 +- 1.2) kJ/mol, respectively. From these values, the corresponding standard molar enthalpies of formation in the solid phase were obtained as: (59.55 +- 1.28), (2.71 +- 1.50), and (13.53 +- 1.53) kJ/mol, respectively. The enthalpies of formation in the gas phase were determined using the experimental enthalpies of formation in the solid phase and predicted values of the enthalpies of sublimation. Additionally, the enthalpies of formation in the gas phase were calculated by means of the Gausian-4 theory, using several gas-phase working reactions, and were compared with those found using the predicted enthalpies of sublimation.

Compounds

#	Formula	Name
1	H2O4S	sulfuric acid
2	CO2	carbon dioxide
3	N2	nitrogen
4	H2O	water
5	O2	oxygen
6	C7H6N2S	2-benzothiazolamine
7	C8H8N2S	4-methyl-2-benzothiazolamine
8	C8H8N2S	6-methyl-2-benzothiazolamine

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	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	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	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	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	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	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
RXND	6 1 2 3 4 5	Specific internal energy of reaction at constant volume, J/g			Rotating bomb calorimetry	1
RXND	7 1 2 3 4 5	Specific internal energy of reaction at constant volume, J/g			Rotating bomb calorimetry	1
RXND	8 1 2 3 4 5	Specific internal energy of reaction at constant volume, J/g			Rotating bomb calorimetry	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Standard enthalpies of formation of 2-aminobenzothiazoles in the crystalline phase by rotating-bomb combustion calorimetry

Camarillo, E. A., Mentado, J.[Juan], Flores, H.[Henoc], Hernandez-Perez, J. M.[Julio M.]

ABSTRACT