Energetics of H-atom addition to naphthalene: A thermochemical cycle from tetralin to naphthalene

Abstract

The C–H bond dissociation enthalpies (BDEs) of molecules related to naphthalene radical chemistry were investigated using quantum chemistry calculations (CBS-QB3 and CCSD(T∗)-F12), and the C–H BDE in 1,2-dihydronaphthalene was determined using time-resolved photoacoustic calorimetry. A thermodynamically consistent data set of the energetics (C–H BDEs and enthalpies of formation) of the molecules involved (naphthalene, 1- and 2-hydronaphthyl radicals, 1,2- and 1,4-dihydronaphthalene, tetralyl radical, and tetralin) is presented. It was constructed using a thermodynamic cycle based on the simple notion that BDEs represent the difference between two states, bridging accurate experimental enthalpies of formation of the parent compounds with theoretical and experimental C–H BDEs leading to, and from, the radicals.