Rovibrational spectra of DCF3 in the 1900cm−1 region: High-resolution study of the v3=v4=1/v3=2, v6=1 Fermi-interacting levels

Adina Ceausu-Velcescu (1) , Petr Pracna (2)

1 LAMPS - LAboratoire de Modélisation Pluridisciplinaire et Simulations
2 J. Heyrovsky Institute of Physical Chemistry

The degenerate combination levels of E symmetry v3 = v4 = 1 (1900.21 cm−1) and v3 = 2, v6 = 1 (1889.30 cm−1) were investigated for the first time with high-resolution, using a Fourier-transform infrared spectrum recorded in the 1600–2000 cm−1 region, at a resolution of 0.0024 cm−1. These combination levels strongly interact through a Fermi-type anharmonic coupling, which plays an essential role in the studied system. Besides the Fermi-interaction, the other important Coriolis (Δk = ±1, Δl = ∓2) and higher-order (Δk = Δl = ±2) inter-vibrational interactions were also considered, in a similar manner as in the lower ν3 + ν6/ν4 dyad [P. Pracna et al., J. Mol. Spectrosc. 259 (2010) 1–10]. The fitted wavenumbers of the rovibrational transitions of the ν3 + ν4 and 2ν3 + ν6 bands provide a set of molecular parameters which ensure an accurate reproduction of the spectrum. Moreover, these molecular parameters show good agreement with those of the lower system ν3 + ν6/ν4.

Mots clés: Deuterated fluoroform; Combination bands; Fermi interaction

Domaines: Physique [physics]

Adina Ceausu-Velcescu, Petr Pracna. Rovibrational spectra of DCF3 in the 1900cm−1 region: High-resolution study of the v3=v4=1/v3=2, v6=1 Fermi-interacting levels. Journal of Molecular Spectroscopy, 2014, 295, pp.31-36. ⟨10.1016/j.jms.2013.11.004⟩. ⟨hal-01143079⟩