High-resolution FTIR study of the ν2 band of CH2F2 and Coriolis interaction between the ν2 and ν8 states

Abstract

The very weak ν2 (1509.15cm−1) band of the CH2F2 molecule has been observed for the first time in infrared. The high-resolution (0.002cm−1) FTIR absorption data of this band have been analyzed by taking into account the Coriolis interaction with the ν8 (1435.63cm−1) state. A strong intensity perturbation was observed which enhances the intensity of the ν2 band. More than 1500 (J≤57 and Ka≤21) transitions were assigned in the ν2 band, and a simultaneous weighted least-squares fit of the data of the ν2 and ν8 bands was carried out including microwave data. The molecular parameters and Coriolis interaction parameters obtained from the fit satisfactorily reproduce the observed relative intensity of the spectrum. By simulating the spectrum, positive perturbation has been confirmed.