Energetic Properties, Spectroscopy, and Reactivity of NF3O.

The heats of formation of NF3O and similar C, S, and Si systems are predicted using the accurate composite computational chemistry Feller-Peterson-Dixon (FPD) method. The harmonic vibrational frequencies at the CCSD(T)/aug-cc-pVTZ level are reported and compared to the experimental values for NF3O, its isoelectronic species CF3O- and NF4+, and NF3. The infrared intensities were calculated at the MP2/aug-cc-pVTZ level and show that the infrared absorption is predicted to be like those of CF2Cl2 and SF6 within a factor of ∼2. The calculated heats of formation are in good agreement with the available experimental values. These heats of formation are used to calculate a range of bond dissociation energies (BDEs). It is predicted that NF3O is unlikely to decompose either thermally or photolytically in the troposphere. The potential energy curves for the decomposition of NF3O to NF2O + F are all repulsive, as are the channels to form NF3 and either O3P or O1D. The predicted persistence of NF3O in the troposphere is attributed to the high barrier of its reaction with the OH radical and that light with the wavelength needed for its photodissociation will not reach the troposphere. Reliable experimental measurements of the global warming potential of NF3O are needed to confirm our predictions that NF3O is like NF3 in this respect.