Free jet IR spectroscopy of (32SF6)2 in the 10 μm region

Abstract

The rotation-vibration spectra of (32SF6)2 have been studied near the ν3 band of the 32SF6 monomer. The parallel band 14 cm−1 below the monomer band origin shows a well resolved J-structure, while the perpendicular band 8 cm−1 above the origin exhibits several Q-branch peaks as the only resolved strong lines. The structure of (32SF6)2 is consistent with a D2d symmetry from the intensity alternation and the existence of a first-order Coriolis interaction observed in the perpendicular band. The energy difference between the two bands is very close to the value calculated by a dipole–dipole and dipole-induced dipole interaction model, while the location of the two bands is blueshifted from the calculated values by about 2 cm−1. The possible influence of internal rotation is discussed.

High-order harmonic transient grating spectroscopy of SF6molecular vibrations

“…This van der Waals dimer has consequently four vibrational modes at frequencies smaller than 40 cm −1 , all of them being Raman active. The main experimental signature of the dimer has been observed in IR spectroscopy as a 20 cm −1 splitting of the υ 3 at 948 cm −1 , due mainly to a dipole-dipole interaction [27]. No Raman spectroscopy has been achieved on SF 6 dimers to the best of our knowledge.…”

Infrared absorption spectra of SiF4 and its clusters in solid parahydrogen

“…It is known that the triply degenerated 3 modes of SF 6 and SiF 4 split into the Z and X,Y modes in the dimer ( Z / = X,Y ) because the vibration associated with the intermolecular axis (Z) is not equivalent to those with the X and Y axes perpendicular to Z [11][12][13][14][15][16][17][18]. In the case of SiF 4 , X,Y splits further into two peaks in the gas phase [17] while no such splitting was observed in Ar and Xe matrices [10].…”

“…Each spectrum was vertically shifted for clarity. molecules such as, SiF 4 , SF 6 and SiH 4 , have been studied well in the gas phase [11][12][13][14][15][16][17][18]. In the gas-phase low-resolution spectra of these dimers, two broad peaks were observed near the monomer 3 bands.…”

“…The splittings were explained by the dipole-dipole and dipole-induced-dipole interactions between the two molecules. Urban and Takami [17,18] reported rotationally resolved dimer spectra at 10 m of both SF 6 and SiF 4 . The authors found that the 3 mode of SF 6 split into two bands (blue-shifted X,Y and red-shifted Z ) while the X,Y component of SiF 4 split further into two bands.…”

Dimerization constant of SF6 and CF4 in cryosolutions

“…A great deal of interest has been expressed in the spectra of pairs (dimers) of molecules with a relatively large value of the dipole moment derivative by a normal coordinate P P 0 i > 0:3D À Á . The absorption bands of dimers, such as ðSF 6 Þ 2 P 0 3 ¼ 0:55D À Á [1][2][3][4][5], ðCF 4 Þ 2 P 0 3 ¼ À 0:465DÞ [6,7], ðSiF 4 Þ 2 P 0 3 ¼ 0:43D À Á [8] and ðNF 3 Þ 2 P 0 3 ¼ 0:42D À Á [9], have been extensively studied using various experimental techniques. A distinguishing characteristic of these spectra is the large splitting value Dm (Dm $ 20 cm À1 ) of a strongly IR-active vibration m 3 .…”