CORIOLIS PERTURBATIONS IN THE ROTATIONAL STRUCTURE OF THE 2350 {\AA} ELECTRONIC TRANSITIONS OF $S^{16}0_{2}$ AND $S^{18}O_{2}$

Author Institution: Department of Chemistry, University of British ColumbiaRotational analyses have been carried out (from high dispersion plates) of ten bands of the $\tilde{C}^{1}B_{2}- \tilde{X}^{1}A_{1}$ absorption transitions of $S^{16}O_{2}$ and $S^{18}O_{2}$, between 2270 and 2350 {\AA}. The results support the conclusion of Brand, Chiu, Hoy, and Bist, based on lower dispersion spectra, that the level $V_{3} = 1$ of the anti-symmetric stretching vibration lies at considerably less than half the energy of $V_{3} = 2$, Our high dispersion spectra have permitted the Coriolis resonance between the levels 002 and O11 to be studied in some detail for both isotopes. The analysis of the complex interacting triad 100, 012, and 021 in $S^{16}O_{2}$ has shown that there is an extremely strong Coriolis perturbation between 021 and 012, and also a weaker anharmonicity-induced Coriolis perturbation between 100 and 021 which allows the position of the 021 level to be determined accurately: this gives the first direct evidence for the low value of $\nu_{3} ^{\prime}$