NEW VIBRATIONAL QUANTUM NUMBER ASSIGNMENTS FOR THE UV ABSORPTION-BANDS OF OZONE BASED ON THE ISOTOPE EFFECT

A 3m normal incidence vacuum spectrograph has been used to obtain the absorption spectra of 16O3 and 18O3 in the 3100-3600 Å region. The band head positions of the absorption bands in this region (the so called Huggins bands) for normal and isotopic ozone at room and dry ice temperatures have been measured and the isotope shifts determined. The observation of two previously unreported bands in the cooled ozone spectrum at wavelengths longer than the 3514 Å band for normal ozone, as well as the isotope shifts show that the previous assumption that the 3514 Å band is the (000)′←(000)″ transition is incorrect. Vibrational quantum number assignments are made based on the isotope shifts and the vibrational constants for the upper electronic state of the Huggins bands are determined for 16O3 and 18O3. The absorption bands in the region near the O2(a 1Δ g) + O(1D) dissociation threshold appear to be perturbed since their energy spacings are irregular compared to those for the longer wavelength bands. © 1979 American Institute of Physics.