Vibrational levels and anharmonicity in SF6—I. Vibrational band analysis

High-Resolution Jet-Cooled Spectroscopy of SF6: The ν2+ ν6Combination Band of32SF6and the ν3Band of the Rare Isotopomers

“…A preliminary fit was realized by fitting only the positions of the two sublevels and the 6 Coriolis parameter. This gave t {6}{6} 1(1,0F 1g ) F 2u F 2u ϭ Ϫ0.18351 cm Ϫ1 , i.e., 6 Ӎ Ϫ0.475, [10] which is very close to the theoretical value (19,20). The new simulation enabled many new assignments.…”

“…The most complete work ever published on combination, overtone, and hot bands of SF 6 was that of McDowell et al (10,11), who observed 29 bands, but only at a relatively moderate resolution (0.05 cm Ϫ1 ) that did not allow a very detailed analysis. These difficulties are due to the weakness of the combination and overtone bands and to the congestion of the fine structure, for this heavy species.…”

“…Our results are not easy to compare with those of Refs. (10) and (11), because their authors, due to the poorer resolution (0.05 cm…”

First High-Resolution Raman Spectrum and Analysis of the ν5 Bending Fundamental of SF6

“…Up to now, the only existing high-resolution Raman studies of SF 6 concerned the ν 2 band near 643 cm −1 (18) and the ν 1 and ν 1 + ν 3 − ν 3 bands near 775 cm −1 (21,22). The only known ν 5 Raman data are low-resolution spectra (23)(24)(25) that are insufficient to determine precise effective Hamiltonian parameters.…”

High-order harmonic transient grating spectroscopy of SF6molecular vibrations

“…ISR is so inefficient in SF 6 that only a few vibration quanta can be coherently populated by the pump pulses. The high splitting in energy cannot result from vibrational anharmonicities or band combination, which are in the range of ≈1 cm −1 [21,22]. The rotational temperature cannot be responsible for such shifts, since assuming a rotational temperature of 300 K leads to a main rotational energy of ≈6 cm −1 .…”