Bond dissociation energies of organic peroxide compounds

The RO-H, ROO-H, RO-OH, and RO-OCH3 (R CH3, C2H5, iso-C3H7, tert-C4H9, and X-CH2, where X = HO, CH3O, CH3COO, HCO, CH3CO, HOCO, and CH3OCO) bond disso ciation energies were determined based on quantum-chemical calculations of the heat of isodesmic reactions and by comparative calculations relative to the D(RO-H) dissociation energies. The two approaches to calculating the s trength of peroxide bonds gave consistent results. The O-O bond dissociatio n energies remained almost constant in a series compounds under considerati on and equaled 191.7 +/- 3.2 kJ/mol for RO-OH and 162.3 +/- 3.4 kJ/mol for RO-OCH3 (calculations with the 3-21G basis set). The O-H bond dissociation energies were noticeably influenced by the nature of substituent R; for hyd roperoxides, D(ROO-H) linearly increased with the Taft induction constant s igma*(R).