Molecular structure and energetics of BrOx radicals (where x=1, 2, and 3)

The equilibrium structures, vibrational spectra and heats of formation for BrO, OBrO, and sym-BrO3 have been investigated using high levels of ab initio molecular orbital theory. Methods include second-order Møller–Plesset perturbation theory (MP2), density functional theory, and singles and doubles coupled-cluster theory which incorporates a perturbational estimate of effects of connected triples excitation [CCSD(T)]. At the highest level of theory, CCSD(T)/6-311+G(3df)//CCSD(T)/6-311G(2df), the 0 K heats of formation for BrO, OBrO, and sym-BrO3 are predicted to be 27.5±3, 34.5±3, and 63.2±3 kcal mol−1, respectively.