Thermodynamic properties of sesquiterpene lactone grossheimin

Abstract

The enthalpy of dissolution of sesquiterpene lactone grossheimin C₁₅H₁₈O₄ is measured using a DAK-I-IA calorimeter at a lactone/ethanol (96%) molar ratios equal to 1 : 18000, 1 : 36000, and 1 : 72000. The standard enthalpy of dissolution of grossheimin in a 96% ethanol solution is calculated based on the resulting data. The temperature dependence of the heat capacity of grossheimin C_p^° ∼ f (T) is studied by means of dynamic calorimetry using a IT-C-400 device in the temperature range of 298.15–423 K. An equation describing this dependence is derived. The standard enthalpies of combustion, melting, and formation of grossheimin are calculated using approximate methods.