RT info:eu-repo/semantics/article T1 Internal rotation analysis of the microwave and millimeter wave spectra of fluoral (CF3CHO) A1 Bermúdez Arias, María Celina A1 Motiyenko, Roman A1 Cabezas, Carlos A1 Ilyushin, Vadim V. A1 Margulès, Laurent D. A1 Endo, Yasuki A1 Guillemin, Jean-Claude K1 Molecular spectroscopy K1 Espectroscopía molecular K1 Rotational spectroscopy K1 Espectroscopía rotacional K1 Fluorinated aldehydes K1 Aldehídos fluorados AB The rotational spectrum (4–40 GHz and 50–330 GHz) has been measured and analyzed for trifluoroacetaldehyde, also known as fluoral (CF3CHO), which is one of the degradation products of the fluorinated contaminants emitted into the atmosphere. The complexity of the spectroscopic analysis of this molecule arises from the strong coupling between the internal rotation motion of CF3 group and the overall rotation of the molecule. The value obtained for its coupling constant (ρ = 0.91723481(49)) is comparable to the corresponding value of methanol (CH3OH, ρ = 0.81), which is known for its complex spectrum. A total of 12,322 transitions of the ground, the first and second excited torsional states (ΔE1υt = 62.0183(13)cm−1; ΔE2υt = 120.3315(13)cm−1) with J ≤ 50 were included in the analysis that was performed employing the rho-axis-method (RAM), and the RAM36 code. A fit within experimental error (root mean square deviation equals to 35 kHz) has been achieved for this dataset using 47 parameters of the RAM torsion-rotation Hamiltonian. In the course of the analysis, it became evident that for such high ρ value, as it is determined for fluoral, a larger than usual torsional basis set at the first diagonalization step of the two-step diagonalization procedure is required for achieving a fit within experimental error. PB Elsevier SN 1386-1425 YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/55698 UL https://uvadoc.uva.es/handle/10324/55698 LA eng NO Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2022, vol. 274, 121071 NO Producción Científica DS UVaDOC RD 12-sep-2024