Coherent Raman and Infrared Studies of Sulfur Trioxide
E T. Chrysostom, N Vulpanovici, Tony Masiello, J Barber, J W. Niblez, A Weber, A G. Maki, Thomas A. Blake
High resolution (0.001 cm-1) coherent anti-Stokes Raman scattering (CARS) was used to observe the Q-branch structure of the IR-inactive Ņ1 symmetric stretching mode of 32S 1603 and its various 18O isotopomers. The Ņ1 spectrum of 32S1603 reveals two intense Q-branches In the 1065-1067 cm-1 region, with surprisingly complex vibrational-rotational structure not resolved in earlier studies. Efforts to simulate this with a simple Fermi-resonance model involving Ņ1 and 2 Ņ4 states do not reproduce the spectral detail nor do they yield reasonable spectroscopic parameters. A more subtle combination of Fermi resonance and indirect Coriolis interactions withnearby states; 2 Ņ4 (I = 0, 2), [nu}2 + Ņ4 (I = 1), 2 Ņ2 (I = 0) is suspected and a determination of the location of these coupled states by high resolution infrared measurements is underway. At medium resolution (0. 125 cm-1), the infrared spectra reveal Q-branch features from which approximate band origins are estimated for the Ņ2, Ņ3, and Ņ4 fundamental modes of 32S18O3, 32S18O216O and 32S18O16O2. These and literature data for 32S16O3 are used to calculate force constants for SO3 and a comparison is made with similar values for SO2 and SO. The frequencies and force constants are in excellent agreement with those obtained by Martin in a recent ab initio calculation .
, Vulpanovici, N.
, Masiello, T.
, Barber, J.
, Niblez, J.
, Weber, A.
, Maki, A.
and Blake, T.
Coherent Raman and Infrared Studies of Sulfur Trioxide, Journal of Molecular Spectroscopy
(Accessed June 9, 2023)