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

The very weak nu(2) (1509.15 cm(-1)) band of the CH2F2 molecule has been observed for the first time in infrared, The high-resolution (0.002 cm(-1)) FTIR absorption data of this band have been analyzed by taking into account the Coriolis interaction with the nu(8) (1435.63 cm(-1)) state. A strong intensity perturbation was observed which enhances the intensity of the nu(2) band. More than 1500 (J less than or equal to 57 and K-a less than or equal to 21) transitions were assigned in the nu(2) band, and a simultaneous weighted least-squares fit of the data of the nu(2) and nu(8) 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. (C) 2000 Elsevier Science B.V. All rights reserved.