A discrepancy between experimental and theoretical thermochemical characterization of some oxygen fluorides

The recently recommended NIST-JANAF Thermochemical Table values for the thermochemical properties of oxygen fluorides are examined critically on the basis of high-level density functional and ab initio G2 calculations. Special attention is given to the enthalpies of formation and it is concluded that, although the proposed values for OF(g), FOO(g) and FOF(g) are reasonable and in agreement with our previously recommended values, the enthalpy of formation recommended for FOOF is too low. A value about 50% larger is proposed and it is recommended that the original 1959 experimental determination of this enthalpy of formation be repeated.