Energetics of naphthalene derivatives, IV⁺: A calorimetric and calculational thermochemical study of the isomeric naphthalenemethanols

The standard (p = 0.1 MPa) molar energies of combustion in oxygen, at T = 298.15 K, of 1-naphthalenemethanol and 2-naphthalenemethanol were measured by static bomb calorimetry. The values of the standard molar enthalpies of sublimation, at T = 298.15 K, were obtained by Calvet microcalorimetry. Combining these results the standard molar enthalpies of formation of the compounds, in the gas phase, at T = 298.15 K, have been calculated. [image omitted] (kJmol-1) [image omitted] (kJmol-1) [image omitted] (kJmol-1) 1-Naphthalenemethanol 132.5 2.9 102.3 1.9 30.2 3.5 2-Naphthalenemethanol 134.9 3.3 106.0 2.1 28.9 3.9 Density functional theory with the B3LYP functional and two different basis sets, 6-31G(d) and 6-311G(d, p), were used to optimize the geometries of the two substituted naphthalenes. Additionally, ab initio second order Mller-Plesset calculations were also used at the MP2(FULL)/6-31G(d), MP2/6-31 + G(d), and MP2(FULL)/6-31 + G(d) levels. The calculation of the energies of appropriate isodesmic reactions allowed the estimation of the standard molar enthalpies of formation in the gas phase for the compounds. The experimental measurements and both sets of quantum chemical calculations were in good agreement for both isomers.