Contribution to the Analysis of the3A2←X1A1“Wulf” Transition of Ozone by High-Resolution Fourier Transform Spectrometry

Abstract The analysis of the rotational structure of the high-resolution Fourier transform 0 0 0 absorption spectrum of the 3 A 2 ← X 1 A 1 band system of the “Wulf” transition of the isotopomer 16 O 3 of ozone is reported for the first time. With a near pure case (b) coupling model for the upper triplet state, we have assigned a significant portion of the spectrum, mainly the F 1 ( J = N + 1) and F 2 ( J = N ) spin components, primarily in the lower frequency region of the band. The lines corresponding to the F 3 ( J = N − 1) component are weak at lower frequencies and heavily congested in the central and higher frequency regions of the spectrum. Perturbations and predissociation phenomena have reduced the effective lifetime of the metastable 3 A 2 state and have also limited the number of transitions included in the least-squares fit of the band. Approximately 100 lines have been assigned in the range from 9100–9550 cm −1 . Three rotational, three centrifugal distortion, three spin–rotation, and one spin–spin constant were varied. The geometry of the molecule in the 3 A 2 state, as determined from these constants, is r = 1.345 A and θ = 98.9°, in good agreement with ab initio results.