The synthesis of CF3OONO2 is accomplished by UV photolysis (254 nm) of a mixture of CF3I, NO2, and O-2. The pure product is isolated after trap-to-trap condensation. The removal of byproducts is accomplished by treatment of the crude product with O-3. To complement the known physical and spectroscopical properties of CF3OONO2, the IR and UV absorption cross sections are determined, 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 extremely 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 reproduce the experimental geometry satisfactorily whereas the HF/3-31G* approximation predicts a much shorter O-N (1.390 Angstrom).