Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

Absolute vapor pressures of 1-Cl-adamantane, 2-Cl-adamantane, 1-Br-adamantane, 2-Br-adamantane, aswell as of Br-cyclohexane were measured by using the transpiration method. Standard molar enthalpiesof sublimation of halogen substituted adamantanes at 298.15 K were derived from vapor pressure tem-perature dependences. Standard molar enthalpies of solution of adamantane and halogen adamantanesin cyclohexane were measured with a high-precision solution calorimeter. A theoretical procedure basedon the solution calorimetry was applied to derive sublimation enthalpies of halogen adamantanes inde-pendently. Molar enthalpies of fusion were measured with help of DSC. The consistent data set of phasetransitions for each compound was evaluated and used for discussion of structure-property relations inadamantane and cyclohexane derivatives. A simple way to predict enthalpies of vaporization of com-pounds containing six-membered rings was suggested for practical thermochemical calculations.