The thermodynamics of vaporization of 1,3,5-trimethyladamantane

The boiling points of 1,3,5-trimethyladamantane were determined ebulliometrically at saturated vapor pressures 6.2-99.6 kPa. Equations describing the temperature dependence of saturated vapor pressure and of the enthalpies of vaporization were obtained, and the normal boiling temperature was calculated. The enthalpy of vaporization at 313.15 K was determined calorimetrically; the Delta(nu)H(o) values obtained by two methods coincided to within the error of measurements. The density of the substance was measured in the temperature range 293-303 K. The experimental data were used to calculate the critical parameters. The vapor pressure data were extrapolated to the whole region of the existence of the liquid phase from the triple to the critical point.