High resolution investigation of the v3 band of trifluoromethyliodide (CF3I).

The high-resolution absorption spectrum of trifluoromethyliodide (CF 3 I), an alternative gas to chlorofluorocarbons but with potential greenhouse effects, has been recorded at 0.001 cm − 1 resolution in the 200–350 cm − 1 region with the Bruker IFS125HR Fourier transform spectrometer at synchrotron SOLEIL. Due to the spectral congestion and the presence of numerous hot bands, the spectra have been recorded at the AILES Beamline facility at SOLEIL either at room temperature using a 150 m optical path length cell or at 163 K using the new LISA-SOLEIL cryogenic cell and at the Australian synchrotron using a flow cooling cell. This enables a detailed analysis of the v 3 band at 286.29712(3) cm − 1 of CF 3 I. The results of previous microwave measurements in the v 3 = 1 and v 6 = 1 vibrational states (Walters and Whiffen, 1983; Wahi, 1987) were combined with those of the present infrared analysis of the v 3 band to obtain an improved set of parameters for the v 3 = 1 (C–I stretching) and v 6 = 1 (I–C–F bending) interacting vibrational states accounting for the Coriolis resonance coupling the v 3 = 1 energy levels with those of the dark v 6 = 1 state (located at ∼261.5 or at ∼267.6 cm − 1 ). Finally, a first investigation of the 2 v 3 − v 3 hot band is also performed. [ABSTRACT FROM AUTHOR]