Measurements and rovibrational study of the CH2FCl nu(4) band by tunable diode laser spectrometer

The gas-phase infrared spectrum of natural CH2FCl has been investigated in the v(4) band region around 1070 cm(-1) at a resolution of 0.002 cm(-1) using a tunable diode laser spectrometer. This fundamental of A' symmetry gives rise to an a/b hybrid band where the a-type component dominates. The rovibrational analysis led to the identification of more than 2400 transitions with J less than or equal to 55 and K-a, less than or equal to 17 for the main isotopic species. A number of K-a subbands were found to be affected by perturbations, through Coriolis or Fermi resonance, with the nearby states v(9) or v(5) + v(6), respectively. From the interaction effects, the second-order a-axis Coriolis coupling parameter was determined. Using Watson's A-reduction Hamiltonian in the I-r representation, a set of effective constants for the (CH2FCl)-Cl-35 v(4) band was derived employing transitions free of major resonance contribution. From spectral simulation, it was found that the intensity contributions of the a- and b-type components are about 70 and 30%, respectively. (C) 1996 Academic Press, Inc.