The Infrared Laser Spectrum of CF2[[dbnd]]CHF near 1360 cm−1: Rovibrational Analysis of the ν3 Fundamental

Abstract

The infrared spectrum of CF2[]CHF has been studied in the ν3 fundamental region around 1360 cm−1 at a resolution of about 0.002 cm−1 using a tunable diode laser spectrometer. This vibration of symmetry species A′ gives rise to an a/b hybrid band with a prevalent contribution of the b-type component. Both J and K structures have been resolved in different subbranches and the rovibrational analysis led to the assignment of more than 2000 lines with J ≤ 71, Ka ≤ 26, and Kc ≤ 71. The ν3 band is affected by first-order b-type Coriolis resonance with the ν10 + 2ν12 and ν7 + ν10 states, and the strongest interaction effect has been found for the Ka′ = 11 and 12 levels; some crossings for low Ka values, due to the perturbation with the ν10 + 2ν12 vibration, have also been located. Using Watson′s A-reduction Hamiltonian in the Ir representation, about 1700 transitions, free of major resonance contribution, provided a set of effective molecular parameters for the ν3 = 1 state. Although none of the interacting levels have been observed, a few parameters for the ν10 + 2ν12 combination have been determined from the perturbation effects near the crossings.