The Infrared Spectrum of Ozone from 0.6 to 2.8 Microns

The spectrum ozone from 0.6 to 2.8 microns has been investigated under medium dispersion. By use of a multiple pass cell an equivalent path of 60 cm ozone was achieved with a 2.5% concentration of ozone in oxygen. Eleven new overtone and combination bands of the ground state molecule were observed in the range 3700 to 5000 cm-1. Using these bands along with previously reported fundamental and lower overtone and combination bands, the three linear and six quadratic constants in the vibrational energy expression are calculated, leaving nine hands to check the band assignments and calculated constants. The linear constants are then used to calculate the two potential constants of ozone assuming a valence force field. The third independent equation checks satisfactorily, indicating the adequacy of the valence force field for ozone. In the region 0.6 to 1.1 microns, the Wulf vibronic bands were investigated. Rather surprisingly, one band at the red end of the series shows structure. A partial analysis of this band and a consideration of other factors offer evidence that the Wulf bands arise from a transition between two excited states. In particular, a 1A2 ← A1B1 transition is proposed. The weak Chalonge-Lefebvre system at 3440 A is tentatively identified as the forbidden 1A2 ← x1A1. Several objections, one perhaps fatal, are given to the proposed transition.