Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

The solution calorimetry approach was applied for the determination of the sublimation enthalpies for cyano-aromatic compounds. According to this approach, the vaporization/sublimation enthalpies were estimated as a difference between solution (cr/l to the solution) and solvation (gas to the solution) enthalpies in acetonitrile as a solvent. The solvation enthalpy of studied compounds was calculated using the previously developed and tested additive scheme. The solution enthalpies of five cyano-aromatic compounds were measured experimentally for the first time by using solution calorimeter. The new approach for the evaluation of the condensed state enthalpy of formation by using first principles calculations and solution calorimetry technique is proposed. In most cases obtained results are in good agreement with literature values. Apparatus for determination of vapor pressure by using the transpiration method was developed. The experimental setup was tested by measuring the vapor pressure of pure naphthalene. Vapor pressures for 1- and 2-cyano-naphthalenes were measured by using the newly elaborated transpiration setup. Experimental and calculated values of sublimation enthalpies are in good agreements with the most reliable available literature data. Sublimation enthalpy of 9-cyano-anthracene was obtained by solution calorimetry for the first time.