Experimental determination of the α and β C-H bond dissociation energies in naphthalene

The acidities of the two different sites in naphthalene (1α and 1β) and the electron affinities of the α- and β-naphthyl radicals were measured using a Fourier transform mass spectrometer. Both carbon-hydrogen bond dissociation energies for naphthalene also were obtained, in this case via the application of a thermodynamic cycle. The final results are ΔH(acid)(o) (1α) = 394.2 ± 1.2 kcal mol^-1, ΔH(acid)(o) (1β) = 395.5 ± 1.3 kcal mol^-1, EA(α) = 31.6 ± 0.5 kcal mol^-1, EA(β) = 31.6 ± 0.5 kcal mol^-1, BDE(1α) = 112.2 ± 1.3 kcal mol^-1 and BDE(1α) = 111.9 ± 1.4 kcal mol^-1, and they are compared to benzene and phenyl radical as well as ab initio and density functional theory (B3LYP) calculations. Copyright (C) 2000 John Wiley and Sons, Ltd.