IR and UV absorption cross sections, vibrational analysis, and the molecular structure of trifluoromethyl peroxynitrate, CF3OONO2

The synthesis of CF3OONO2 is accomplished by UV photolysis (254 nm) of a mi xture of CF3I, NO2, and O-2. The pure product is isolated after trap-to-tra p condensation. The removal of byproducts is accomplished by treatment of t he crude product with O-3. To complement the known physical and spectroscop ical properties of CF3OONO2, the IR and UV absorption cross sections are de termined, and a complete vibrational analysis is performed. On the basis of the UV data, the photolytic half-life in the troposphere is calculated to be 30 days. The molecular structure of CF3OONO2 is determined by gas-phase electron diffraction and quantum chemical calculations (HF/3-21G, HF/6-3lG* , and B3PW91/6-311+G*). The peroxide CF3OONO2 possesses a skew structure (C -1 symmetry) with a GOON dihedral angle of 105.1(16)degrees and an extremel y long O-N bond of 1.523(7) Angstrom, which is in accordance with its low O -N bond-dissociation energy. The HF/3-21G and B3PW91/6-311+G* methods repro duce the experimental geometry satisfactorily whereas the HF/3-31G* approxi mation predicts a much shorter O-N (1.390 Angstrom).