24.
The four 5
v 3 bands of
18O enriched ozone have been observed and analysed for the first time. Two species (
16O
18O
16O and
18O
16O
18O) belong to the C
2v symmetry group and two other (
18O
18O
16O and
16O
16O
18O) to the C
s symmetry group. They have been recorded at a resolution of 0.008 cm
?1 with a pathlength of 32.16 m. Despite the very weak absorptions observed, almost 250 energy levels have been derived for each of the 4 species, with
J ? 35 and
K a ? 13, and suitable sets of Hamiltonian parameters have been determined. For 3 species it has been necessary to account for the resonance between the (005) and (311) states to correctly reproduce the spectra observed. These resonances, anharmonic for C
2v, and hybrid (both anhar-monic and Coriolis) for C
s symmetry confirm the accidentally extremely strong coupling between the (005) and (311) states for
16O
3, due in that case to the very close distance between unperturbed energy levels. This work also confirms the excellent prediction of band centres of these four species derived from the recently determined isotopically invariant molecular potential function.
相似文献