Contribution to the Analysis of the 3A2 <-- &Xtilde;1A1 "Wulf" Transition of Ozone by High-Resolution Fourier Transform Spectrometry.

The analysis of the rotational structure of the high-resolution Fourier transform 0(0)0 absorption spectrum of the 3A2 <-- &Xtilde;1A1 band system of the "Wulf" transition of the isotopomer 16O3 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 F1 (J = N + 1) and F2 (J = N) spin components, primarily in the lower frequency region of the band. The lines corresponding to the F3 (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 3A2 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 3A2 state, as determined from these constants, is r = 1.345 Å and theta = 98.9 degrees, in good agreement with ab initio results. Copyright 1998 Academic Press.