Infrared spectral absorption intensities in the ν3 and ν4 regions of SF6

Infrared photofragmentation spectra of size-selected SF6⋅Ar+n cluster ions

“…4͑b͒; again there is no evidence of a splitting and the magnitude of the frequency shift ͑Ϫ17 cm Ϫ1 with respect to 32 S͒ is identical to that seen for the isolated, neutral molecule. 38 We believe the above observations support our original conclusion that, in the cluster SF 6 •Ar 3 ϩ , the positive charge resides on the argon component and, therefore, reactions ͑4͒ and ͑5͒ are driven by infrared induced charge transfer. 31 Indirect support regarding the position of the charge is given by the absence of the ions SF 6 •Ar ϩ and SF 6 •Ar 2 ϩ from the mass spectra; both Ar ϩ and Ar 2 ϩ have ionization energies which are larger than that proposed for SF 6 ͑14.4 eV͒.…”

“…6 for 32 SF 6 •Ar 7 ϩ , but redshifted by an amount appropriate for the change in mass of the isotope. 38 Lorentzian profiles have been used previously to represent the ir absorption line shapes of SF 6 molecules trapped in rare gas matrices; 11 in contrast, Scoles and co-workers have made extensive use of gaussian profiles to fit their data on SF 6 The profiles shown in Figs. 6 -10 exhibit considerable variation as a function of cluster size.…”

Vibrational predissociation of SF6 dimers and trimers

“…The source conditions are characterized by a stagnation temperature T O = 233 K, a stagnation pressure Po between 1,000 and 1,850 torr and a nozzle diameter of 30#m; only casual remarks will be found based on observations at other source conditions, The SF6-component consist of 4.2% 34SF6molecules [8]. In this paper we restrict ourselves to the observations made with the 5% SF6-He mixture.…”

Isotope shifts in spectra of molecular liquids

“…In spectra of solutions in liquid argon, resonances are observed as doublets of narrow bands with the Lorentz contour, quantitative characteristics of which are presented in Table 3. Corresponding values of interaction matrix elements W FR were calculated using well-known formulas [1] of the Fermi resonance, (2) where χ is the splitting, R is the intensity ratio of the experimental doublet, and δ is the spacing between levels unperturbed by the Fermi resonance. Parameters W FR are functions of cubic force constants of the molecule, and corrections to their values from poten-…”

“…As an example, we can present a comparison of isotope shifts in the IR spectrum of a solution in liquid argon with shifts that were determined from the spectra of the gas phase [2][3][4][5][6][7][8][9] (Table 1). It is important to note that Table 1 presents data for bands that are combined with vibrations that are strong in the dipole absorption.…”