Recent calculations by Montgomery and co-workers' suggest that the accepted value for the heat of formation of COF, is in error by more than 6 kcal mol-'. Additional calculations reported here support this contention.The revised value for A~H~~~B ( C O F~) permits a reanalysis of available kinetic and thermodynamic data on the energies of a number of other small fluorine-containing molecules, including CF3O radical, CFsOF, and CF3-OOCF3, and resolves a number of discrepancies between previous calculated and experimental results. It also allows a reevaluation of the energetics of H F loss from CFsOH, an important reaction in the atmospheric degradation of several HFCs.