INFRARED STUDY OF THE NU-5 FUNDAMENTAL OF CF2HCL BY FTIR SPECTROSCOPY

The infrared spectrum of natural CF2HCl has been investigated in the ν5 region at a resolution of ca. 0.004 cm-1 using a Fourier transform infrared spectrometer. The ν5 fundamental, which can be approximately described as a CF2 deformation mode, gives rise to an a c hybrid band. The rovibrational analysis has been carried out in the P and R branches, and more than 1000 lines belonging to CF2H35Cl have been assigned. Transitions with K′a ≤ 6, J′ up to 48 (a-type) and K′e ≤ 11, J′ up to 33 (c-type) have been identified in the region investigated. From the assigned transitions a set of spectroscopic constants using Watson's A-reduction Hamiltonian has been derived for CF2H35Cl ν5 band. Simulations in the Q-branch region enabled us to establish the character of the hybrid band which was determined to be composed of about 30% of a and 70% of c components. © 1991.