FOURIER-TRANSFORM INFRARED-SPECTROSCOPY OF THE NO3 RADICAL

The infrared spectrum of NO3 was observed in the 1300-2800 cm-1 region by a high-resolution FT-IR spectrometer using the reaction of F atoms with HNO3. Three 2E'-2A2' bands were newly observed in the 1927, 2024, and 2155 cm-1 region in addition to the 1492, 2518, and 2585 cm-1 bands observed previously by a diode-laser system. The 2024 and 2155 cm-1 bands were analyzed by using a D3h Hamiltonian to derive molecular constants. It was found that the obtained spin-orbit and Coriolis coupling constants in the 2E' states are very different for different vibronic states. The vibronic assignments of these bands are discussed.