Thermodynamic study of selected monoterpenes

A thermodynamic study of important biogenic compounds, (–)-α-pinene, (–)-β-pinene, (–)-cis-verbenol, and (–)-verbenone, is presented in this work. The vapor pressure measurements were performed using the static method over the environmentally important temperature range from 238 to 313 K. The sublimation and vaporization enthalpies were derived from these measurements as well as directly determined by a Calvet high temperature microcalorimeter. Heat capacities of condensed phases were measured by Calvet and drop calorimetry in the temperature interval from 273 to 355 K. The thermodynamic properties of the ideal-gas state were calculated by combining statistical thermodynamics and density functional theory (DFT) calculations. The trends in thermodynamic properties within the group of compounds possessing similar molecular structures are discussed.

► (–)-α-Pinene, (–)-β-pinene, (–)-cis-verbenol, and (–)-verbenone were studied. ► New thermodynamic data were measured and calculated. ► Trends in thermodynamic properties are rationalized.