We observed and analyzed a b-axis Coriolis resonance between higher J states of the ν6 + ν9 combination band and the ν8 fundamental of ketene in the spectral region 940-970 cm-1. The interaction resonantly couples Ka = 1 states of the combination band to Ka = 0 states of the fundamental and also affects Ka = 1, 2 states in the fundamental. Due to the involvement of strongly asymmetry-split low K levels, the rotational constants and band origin of ν6 + ν9 could be accurately determined and are discussed in the light of high-quality anharmonic force fields. The Coriolis coupling parameter, ζb8,6+9, is very precisely determined. A smaller perturbation, which could not be fully analyzed, is tentatively attributed to Ka = 2 upper states in the ν5 + ν9 band.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry