Analysis of High-Resolution Infrared and Ņ1 CARS Spectra of 34S18O3

Published

October 16, 2008

Author(s)

Tony Masiello, J Barber, E T. Chrysostom, J Nibler, A G. Maki, A Weber, Thomas A. Blake, R L. Sams

Abstract

Three fundamental modes and several hot bands of ³⁴S¹⁸O₃ have been investigated using both infrared spectroscopy and coherent anti-Stokes Raman scattering spectroscopy (CARS). Coriolis coupling effects are particularly noticeable in ³⁴S¹⁸O₃ due to the close proximity of the Ņ₂ and Ņ₄ fundamental vibrations, whose wave number values are 477.508 64(5) and 502.055 65(4) cm^-1. The uncertainties in the last digits are shown in parentheses and are two standard deviations. Hot band transitions from Ņ₂, Ņ₄ levels give access to infrared inactive Ņ₂, Ņ₄ combination/overtone levels which interact strongly with levels of the Raman-active Ņ₁ symmetric stretching mode due to indirect Coriolis couplings, l-resonances, and Fermi resonances. The result is a complex Ņ₁ CARS Q-branch spectrum that is the most perturbed of the four SO₃ isotopomers we have studied. The relative importance of these interaction terms on the Ņ₁ CARS spectrum is examined in some detail and accurate rovibrational sonstants are deteremined for all of the mixed states, leading to deperturbed values of 1004.662(24), 0.000 350 3(9), and 0.000 706 6(12) cm_-1 for Ņ₁, α₁^B, and α₁^C, respectively. The B_e value is found to be 0.310 817(12) cm^-1, which gives an equilibrium bond length r_e of 141.7339(3) pm, in excellent agreement with values of 141.7340(1) and 141.7347(7) pm reported earlier for ³²S¹⁶O₃ and ³⁴S¹⁶O₃.

Citation

Journal of Molecular Spectroscopy

Pub Type

Journals

Keywords

CARS spectroscopy, high resolution, infrared, isotopomer, sulfur trioxide

Citation

Masiello, T. , Barber, J. , Chrysostom, E. , Nibler, J. , Maki, A. , Weber, A. , Blake, T. and Sams, R. (2008), Analysis of High-Resolution Infrared and Ņ₁ CARS Spectra of ³⁴S¹⁸O₃, Journal of Molecular Spectroscopy (Accessed July 27, 2024)