Infrared spectra of 18O-enriched ozones in liquid oxygen solution Original Research Article

FTIR spectra of six ozone isotopomers are studied in liquid O2 solution at 77 K in the spectral range 650–3200 cm−1. Full vibrational assignment is given and relative transition strengths are measured for many previously unobserved absorption bands of 18O-enriched species. Whenever such comparison is possible, most but not all of the relative strengths in solution are found to be in agreement with the rotationless transition moments in the gas phase. An order of magnitude enhancement observed for the hybrid-type v1 transitions in asymmetric 16O16O18O and 16O18O18O molecules is consistent with the calculated off-diagonal vibrational dipole matrix elements for the fundamental transitions in C2v and Cs isotopomers. It is suggested that enhancement of transitions into the states with the even vibrational quantum number v3 may serve as a sensitive criterion for an interaction-induced asymmetric distortion of the O3 potential energy surface by intermolecular interactions via terminal oxygen atoms.