Comments on "Reevaluation of the bond-dissociation energies (.DELTA.HDBE) for H-OH, H-OOH, H-OO-, H-O.cntdot., H-OO-, and H-OO.cntdot."

Abstract

In a recent letter by Sawyer, it was suggested that new values of the bond dissociation energies (BDE), defined for bond-breaking processes in the gas phase at 298 K, for a number of hydrogen- and oxygen-containing species could be determined from half-cell potentials. Discrepancies with accepted values for HO{sub 2} and HO{sub 2}{sup {minus}} were noted. We wish to point out that the bond dissociation energies for H-OO and H-OO{sup {minus}} that were derived by Sawyer are in serious disagreement with those established in the past decade by gas-phase chemical kinetics and photoelectron spectroscopy. These results were not cited by Sawyer. Moreover, computations utilizing half-cell potentials for the derivation of bond dissociation energies must account for substantial solvation effects. When properly calculated, these BDEs are, in fact, in accord with established values.