Study of low-lying electronic states of ozone by anion photoelectron spectroscopy of O−3

Abstract

The low‐lying electronic states of ozone are studied using anion photoelectron spectroscopy of O− 3. The spectra show photodetachment transitions from O− 3 to the X̃ 1 A 1ground state and to the five lowest lying electronic states of the ozone molecule, namely the 3 A 2, 3 B 2, 1 A 2, 3 B 1, and 1 B 1 states. The geometry of the ozonide anion determined from a Franck–Condon analysis of the O3 X 1 A 1ground state spectrum agrees reasonably well with previous work. The excited statespectra are dominated by bending vibrational progressions which, for some states, extend well above the dissociation asymptote without noticeable lifetime broadening effects. Preliminary assignments are based upon photoelectron angular distributions and comparison with ab initio calculations. None of the excited states observed lies below the ground statedissociation limit of O3 as suggested by previous experimental and theoretical results.