Investigating the thermodynamic properties of lactones at various temperatures

The 11-undecanolide enthalpy of vaporization is obtained from the temperature dependence of the vapor pressure measured by transpiration. A conformational analysis of 8-octanolide (I), 11-undecanolide (II), and 13-tridecanolide (III) is performed. Quantum-chemical calculations are performed to study the moments of inertia, vibrational spectra, and most favorable conformations. The ideal gas thermodynamic properties of these compounds in the temperature range of 0-1500 K are determined. A procedure for the additive determination of polynomial coefficients for temperature-dependent properties is developed to assess the thermochemical data for lactones, lactides, and carboxylic hydroxyacids at 298.15–1000 K.