Benchmark thermodynamic properties of 1,3-propanediol: Comprehensive experimental and theoretical study

Abstract

Thermochemical properties of 1,3-propanediol are in disarray. A new standard (p°=0.1MPa) molar enthalpy of formation at the temperature T=298.15K of the liquid 1,3-propanediol was measured using combustion calorimetry. A new molar enthalpy of vaporisation of 1,3-propanediol was derived from the vapour pressure temperature dependence measured by the transpiration method. Thermodynamic data on 1,3-propanediol available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpies of formation data and to recommend the set of vaporisation and formation enthalpies for 1,3-propanediol at T=298.15K (in kJ·mol−1): ΔfHm° (g)=−(410.6±2.2), ΔfHm° (l)=−(481.8±2.2), and ΔlgHm°=(71.2±0.2) as the reliable benchmark properties for further thermochemical calculations. Quantum-chemical calculations of the gas phase molar enthalpy of formation of 1,3-propanediol have been performed using the G3MP2 method and results were in excellent agreement with the recommended experimental values. The standard molar entropy of formation and the standard molar Gibbs function of formation have been calculated.