An extensive thermodynamic study of three monoterpenes, (−)-menthone, (+)-pulegone, and (−)-isopulegol, is presented in this work. Phase behaviour was investigated by a heat-flux differential scanning calorimetry (DSC) from 183 K resulting in detection of polymorphic behaviour of (−)-isopulegol and a noticeably slow crystallization of (+)-pulegone. Two static apparatus were employed for the vapour pressure measurements over a wide temperature range including environmentally important ambient temperatures. Heat capacities of liquid phase were measured by Tian-Calvet calorimetry at temperatures between 266 K and 353 K. Conformational space of the compounds was examined using the density functional theory (DFT) calculations and the ideal-gas thermodynamic properties were subsequently calculated using statistical thermodynamics. A consistent thermodynamic description was developed using the method of simultaneous correlation, where the experimental data for phase behaviour, vapour pressures, and condensed phase heat capacities and calculated ideal-gas heat capacities are treated together.

这项工作提出了对三个单萜（-）-薄荷酮，（+）-pulegone和（-）-异薄荷醇的广泛热力学研究。通过热通量差示扫描量热法（DSC）从183 K研究了相行为，从而检测到（-）-异胡薄荷醇的多晶型行为和（+）-异胡薄荷酮的结晶明显缓慢。在包括对环境重要的环境温度在内的较宽的温度范围内，采用了两种静态仪器进行蒸气压测量。在266 K和353 K之间的温度下，通过Tian-Calvet量热法测量了液相的热容量。使用密度泛函理论（DFT）计算检查了化合物的构象空间，随后使用统计热力学计算了理想气体的热力学性质。 。