Line-by-line intensity measurements of methyl fluoride in the ν2 and ν5 bands

• Published in: Journal of quantitative spectroscopy & radiative transfer 2022-08, Vol.286, p.108218, Article 108218
• Main Authors: Ziadi, H., Fathallah, O. Ben, Chouikha, I. Ben, Tchana, F. Kwabia, Landsheere, X., Aroui, H.
• Format: Article
• Language: English
• Subjects: Band intensity; CH3F; Fourier transform spectroscopy; Line intensity; Sciences of the Universe; Transition dipole moment; ν2 and ν5 bands
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/j.jqsrt.2022.108218

•2040 line intensities in the ν2 and ν5 bands of CH3F were measured.•Transition dipole moments squared were derived.•Analysis of the line intensities and transition dipole moments squared were performed.•The intensity parameters were retrieved. Systematic measurements of line intensities in the ν2 and ν5 bands of CH3F were performed for the first time for 2040 transitions using a mono-spectrum fitting technique utilizing a Voigt and Rautian profiles. The spectra are recorded at room temperature for eight pressures of CH3F from 0.1247 to 2.5080 Torr using the Bruker IFS125HR Fourier Transform spectrometer located at the LISA facility in Créteil. Strong intensity perturbations were observed and analyzed accounting for the strong Coriolis coupling ν2 and ν5 bands and l-type interactions in the ν5 band. The transition dipole moments squared were determined for each line, allowing determination of the vibrational transition moment and the Herman–Wallis coefficients of each band using the Aliev and Watson models. Comparison with data available in the literature permits to test the validity of these models applied to the ν2/ν5 dyad system strongly affected by resonances.