Adamantanes: Benchmarking of thermochemical properties

• Enthalpies of formation of adamantane derivatives measured by combustion calorimetry.
• Vapour pressures measured by transpiration method.
• Enthalpies of solution measured using high-precision solution calorimetry.
• Sublimation enthalpies derived from transpiration and solution calorimetry in agreement.
• Experimental results evaluated and compared with G3MP2 calculations.

Standard molar enthalpies of formation of 2-adamantanone and 1-adamantanol were measured by using high-precision combustion calorimetry. Vapour pressures of 2-adamantanone, 1-acetyl-adamantane, 1- and 2-carboxy-adamantanes were measured by using the transpiration method. Standard molar enthalpies of sublimation of this substituted adamantanes at 298.15 K were derived from vapour pressure temperature dependences. The standard molar enthalpy of solution of 1-acetyl-adamantane in cyclohexane was measured with the high-precision solution calorimetry. An empirical procedure based on the solution calorimetry was developed to derive sublimation enthalpies of substituted adamantanes independently. Molar enthalpies of fusion of 1-acetyl-adamantane, 1- and 2-carboxy-adamantanes were measured with help of DSC. Thermochemical data on oxygen containing adamantane derivatives were collected and evaluated. Gas-phase enthalpies of formation calculated with the high-level quantum-chemical method G3MP2 and compared with the experimental results. The consistent data set of the benchmark quality is suggested for practical thermochemical calculations.