Influence of the position of carbonyl group in ketones on their enthalpies of vaporization and saturated vapour pressures

Information about the structure-property relationship can be useful for the synthesis of compounds with desired properties, analysis of the role of intermolecular interactions in various physicochemical processes and separation of the synthesis product from impurities. In the present work, the influence of the position of the carbonyl group on the saturated vapour pressure and enthalpy of vaporization of ketones was studied. The saturated vapour pressures of isomeric decanones, undecanones and isophorone were measured by the transpiration method. The enthalpies of vaporization of isomeric ketones were determined using various methods: solution calorimetry, transpiration and correlation gas chromatography. The obtained values agree with each other within 1 kJ mol⁻¹. It was shown that 2-alkanones have higher enthalpies of vaporization and lower vapour pressures than 3-, 4-, 5-, 6-alkanones, which can be explained by the stronger intermolecular interactions existing between the molecules of 2-alkanones compared to others isomers.