Vibrational constants and force field of sulfur hexafluoride
The infrared-active combination bands of SF/sub 6/ gas were remeasured and the band origins estimated. These data were combined with the Raman frequencies of Bosworth et al., and with the spectrum of SF/sub 6/ in cryogenic liquid oxygen solutions reported by Bertsev et al., to obtain estimates for the 21 anharmonicity constants X/sub ij/. The resulting harmonic vibrational frequencies were used in a calculation of the general quadratic harmonic force field of SF/sub 6/. The most useful constraint in the F/sub 1//sub u/ symmetry block was the Coriolis constant zeta/sub 3/ = 0.693 +- 0.004 obtained from an analysis of ..nu../sub 3/ resolved with tunable diode lasers; but zeta/sub 4/ estimated from a similar analysis of ..nu../sub 4/, and the /sup 32/S--/sup 34/S isotope frequency shifts reported by Brunet and Perez for these fundamentals, are all in general agreement. The more important valence force constants are f/sub r/ = 5.45 +- 0.03, f/sub rr/(cis interaction) = 0.36 +- 0.01, f/sub rr'/ (trans interaction) = -0.02 +- 0.03, and f/sub ..cap alpha../ approximately 0.83, all in mdyn/A. From the absolute band intensities of Schatz and Hornig and the present force field, the S--F bond moment and its derivative are estimated to be ..mu../sub 0/ = 2.44 +- 0.12 D and delta ..mu../delta r = 4.2 +- 0.3 D/A.
- Research Organization:
- Los Alamos Scientific Lab., NM
- OSTI ID:
- 7361601
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 80:11; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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