DIODE-LASER SPECTROSCOPY OF TRIFLUOROETHYLENE IN THE 8.6-MU-M REGION

The two mid-infrared bands of the CF2=CHF molecule, v(5) centered at 1 172.673 cm(-1) and v(6) + v(9) at 1155.105 cm(-1), were measured on a tunable diode laser spectrometer with a resolution near the Doppler li mit. These vibrations of A' species give rise to nib hybrid bands, eve n though our analysis has pointed out that the intensity of the a-type component is predominant. Most of the J and K structure has been reso lved in different subbranches, and the rovibrational analysis led to t he assignment of about 1400 (J less than or equal to 60, K-a less than or equal to 22, K-c less than or equal to 60) and 90 (J less than or equal to 56, K-a less than or equal to 5, K-c less than or equal to 56 ) lines of the v(5) and v(6) + v(9) bands, respectively. Using Watson' s A-reduction Hamiltonian in the I-r representation, a set of accurate spectroscopic constants for the upper stales has been derived from tr ansitions free of major resonance effects. The rotational structure of the v(5) vibration also exhibits effects of Coriolis perturbation by a state identified as v(7) + v(11). Parameters for the perturber were determined from the interaction effects near the observed crossings, u sing a dyad model including first-order 6-Coriolis interaction. (C) 19 98 Academic Press.