Experimental and computational study on the molecular energetics of benzyloxyphenol isomers

This paper reports a combined experimental and computational thermochemical study of 4-benzyloxyphenol. Static bomb combustion calorimetry and Knudsen mass-loss effusion technique were used to determine the standard (p(o) = 0.1 MPa) molar enthalpy of combustion, Delta H-c(m)o = -(6580.1 +/- 1.8) kJ. mol(-1), and of sublimation, Delta H-g(cr)m(o)= (131.0 +/- 0.9) kJ . mol(-1), respectively, from which the standard (p(o) = 0.1 MPa) molar enthalpy of formation, in the gaseous phase, at T = 298.15 K, Delta H-t(m)o = -(119.5 +/- 2.7) kJ . mol(-1) were derived. For comparison purposes, the gas-phase enthalpy of formation of this compound was estimated by G3(MP2)//B3LYP calculations, using a set of gas-phase working reactions; the results are in excellent agreement with experimental data. G3(MP2)//B3LYP computations were also extended to the calculation of the gas-phase enthalpies of formation of the 2- and 3-benzyloxyphenol isomers. Furthermore, this composite approach was also used to obtain information about the gas-phase acidities, gas-phase basicities, proton and electron affinities, adiabatic ionization enthalpies and, finally, O-H bond dissociation enthalpies. (C) 2011 Elsevier Ltd. All rights reserved.