CORIOLIS INTENSITY PERTURBATIONS OF THE $v_{4}$ BAND OF $SF_{6}$
Loading...
Date
1981
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The FT=IR $spectrum^{1}$ of the $v_{4}$ band of $SF_{6} (615$ $cm^{-1})$ obtained at room temperature reveals that the R-branch has 27% more absorption intensity than the P-branch. This inbalance is substantially larger than the 15% excess predicted by rotational statistics and the non-negligible width of the band. This shift in intensity is a consequence of perturbations on the rovibrational line intensities, from Coriolis interactions between the $v_{4}$ and $v_{3}$ excited states, and also between the ground and combination $v_{3}+v_{4}$ states. Such perturbations can be expressed using a superposed Herman-wall is F-factor of the form $$F(m) = (1+\xi m)^{2}$$, as in some bands of $CH^{2}_{4}$ and $CO_{2}.^{3}$ We have derived an experimental value for $\xi$; using a new formalism involving total branch intensities. Model intensity calculations for the perturbed $\nu$3 band in $SF_{6}$ will be discussed, and estimations will be presented for the $v_{3}$ and $v_{4}$ bands of $UF_{6}$. Finally, weak Coriolis enabling of the normally inactive $v_{6}$ mode is predicted and estimated.
Description
$^{1}$K. G. Kim, W. B. Person, D. Seitz, and B. J. Krohn, J. Mol. Spectrosc. 76, 322-340 (1979). $^{2}$A. G. Robiette and I. M. Mills, J. Mol. Spectrosc. 77, 48-56 (1979). $^{3}$H. D. Downing, B. J. Krohn, and R. H. Hunt, J. Mol. Spectrosc. 55, 66-80 (1975).
Author Institution:
Author Institution: