This paper deals with the least-squares determination of effective rotational constants for the lowest three vibrational states of the ketene (CH2CO) molecule:v5, v6 and v9. Several hundred rotational lines have been assigned in high-resolution Fourier-transform infrared spectra and were fitted to a standard, Watson Hamiltonian in the A-reduction formalism. The effective A rotational constants were used to extract vibration-rotation interaction α values and these values are compared to those obtained from a perturbation formula and to values from highly accurate quantum-chemical calculations in the literature. The results show the strong effects of a-type Coriolis interactions among the modes involved, and prepare the way for full numerical diagonalization-type determination of the vibration-rotation constants.
ASJC Scopus subject areas
- Physics and Astronomy(all)