The energetics of 1-benzosuberone was studied by a combination of calorimetric techniques and computational calculations. The standard (p degrees = 0.1 MPa) molar enthalpy of formation of 1-benzosuberone, in the liquid phase, was derived from the massic energy of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpy of vaporization, at T = 298.15 K, was measured by Calvet microcalorimetry. From these two parameters the standard (p = 0.1 MPa) molar enthalpy of formation, in the gaseous phase, at T = 298.15 K, was derived: -(96.1 +/- 3.4) kJ . mol(-1). The G3(MP2)//B3LYP composite method and appropriate reactions were used to computationally calculate the standard molar enthalpy of formation of 1-benzosuberone, in the gaseous phase, at T = 298.15 K. The computational results are in very good agreement with the experimental value. (C) 2010 Elsevier Ltd. All rights reserved.