When dealing with
organic peroxides in both laboratory and industrial
applications, the relative strengths of the O–O bond are of
vital importance, both from a safety and mechanistic perspective.
Although it is well known that such oxidizing agents are highly reactive,
reliable O–O bond dissociation energies (BDEs) have only recently
been established. In an earlier report, we suggested a median O–O
BDE value of ca. 45 kcal/mol for a variety of well-known peroxides
based upon G2 ab initio calculations. In the present report, we have
calculated the O–O BDE of twenty peroxides of varying structures
at a more accurate CBS-APNO level. We have also compared these bond
energies to the corresponding BDEs calculated with several DFT functionals
and shown that the M06-2X functional produces O–O bond energies
that compare very favorably with G4 and CBS-APNO values.