No abstract

The C-X (X ) C, O, N, S, Br) bond dissociation enthalpies (BDEs) of perfluoroalkanes, perfluoroethers, perfluorotrimethylamine, perfluorodimethyl sulfide, and trifluoromethyl bromide were evaluated by the G2, G2MP2, and G2MS methods. Perfluoroethers had high BDEs of the C-O bond because of the strong negative hyperconjugation between the CF 3 group and lone pair orbitals of oxygen. The BDEs of CF 3 -X bonds could be used as an index of the fire suppression ability.