Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The standard (p = 0.1 MPa) molar energies of combustion in oxygen, at T = 298.15 K, of 5-, 6- and 7-methoxy-alpha-tetralone were measured by static bomb calorimetry. The values of the standard molar enthalpies of sublimation were obtained by Calvet microcalorimetry and corrected to T = 298.15 K. Combining these results, the standard molar enthalpies of formation of the compounds, in the gas phase, at T = 298.15 K, have been calculated, 5-methoxy-a-tetralone -(244.8 +- 1.9) kJ mol 1, 6-methoxy-a-tetralone (243.0 +- 2.8) kJ mol 1 and 7-methoxy-a-tetralone (242.3 +- 2.6) kJ mol 1. Additionally, high-level density functional theory calculations using the B3LYP hybrid exchange correlation energy functional with extended basis sets and more accurate correlated computational techniques of the MCCM/3 suite have been performed for the compounds. The agreement between experiment and theory gives confidence to estimate the enthalpy of formation of 8-methoxy-a-tetralone. Similar calculations were done for the 5-, 6-, 7- and 8-methoxy-b-tetralone, for which experimental work was not done.