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The phase change energetics of adamantane, 1-adamantanemethanol, 1-adamantanethanol, 1-adamantanecarboxylic acid, and 1-adamantaneacetic acid is reported. To conduct the study of the compounds' phase changes, calorimetric techniques and theoretical methodologies were applied. Mole fraction purities, enthalpies, fusion temperatures, and solid phase heat capacities were obtained using differential scanning calorimetry. Enthalpies of sublimation were determined from measurements of mass loss rate and the Clausius-Clapeyron and Langmuir equations, i.e., through thermogravimetric analysis. The gas-phase heat capacities of all stable conformers of the adamantane derivatives at different temperatures were estimated using harmonic oscillator approximation. Finally, the molecular interactions of the adamantane derivatives are discussed. [ABSTRACT FROM AUTHOR]

• Thermogravimetry was used for vapor pressures estimation of two chromones. • Vapor pressures obtained by isothermal thermogravimetry agree with literature data. • Estimates vapor pressures lead to obtain sublimation enthalpies. • Entropies and Gibbs energies were derived from experimental data. In present work, the estimation of vapor pressures of 3-formylchromone and 3-formyl-6-methylchromone by the isothermal thermogravimetry method is presented. Briefly, this method consists of measuring the rate of mass loss as a function of temperature in a cylindrical cell and with a flow of nitrogen. To derive the vapor pressure, the Langmuir equation was used, from which the vaporization constant was calculated using anthracene as a calibrating compound. Subsequently, the vapor pressures 3-fromylchromone and 3-formyl-6-methylchromone were estimated. From the vapor pressure, the enthalpy of sublimation was calculated using the Clausius-Clapeyron equation for each compound at its mean sublimation temperature. Finally, the enthalpy of sublimation was calculated at T = 298.15 K. The entropy and Gibbs energy of sublimation at the same temperature were determined. In order to test the validity of the method, the vapor pressures of phenanthrene and pyrene were calculated. The values obtained by isothermal thermogravimetry agree with those reported by other techniques. [Display omitted] [ABSTRACT FROM AUTHOR]