Analysis of high-resolution infrared and CARS spectra of 32S18O3
- 作者：Masiello ; Tony ; Vulpanovici ; Nicolae ; Barber ; Jeffrey ; Chrysostom ; Engelene t.H. ; Nibler ; Joseph W. ; et. al.
- 关键词：Infrared ; CARS ; Spectrum ; Sulfur trioxide ; Oxygen-18 ; Fermi resonance
- 刊名：Journal of Molecular Spectroscopy
- 出版年：2004
- 期刊代码：129_00222852
- 类别：ch
- 出版时间：September, 2004
- 卷：227
- 期：1
- 页码：50-59
- 文件大小：650 K
摘要
As part of a series of investigations of isotopic forms of sulfur trioxide, high-resolution infrared and coherent anti-Stokes Raman spectroscopies were used to study the fundamental modes and several hot bands of 32S18O3. Upper levels of hot bands originating from the ν2 and ν4 bending mode states have been found to couple strongly to the upper levels of the IR-inactive ν1 symmetric stretch through indirect Coriolis interactions and Fermi resonances. Coriolis coupling effects are particularly noticeable in 32S18O3 due to the close proximity of the ν2 and ν4 fundamental vibrations, whose deperturbed wavenumber values are 486.48813(4) and 504.28477(4) cm−1. The uncertainties in the last digits are shown in parentheses and are two standard deviations. From the infrared transitions, accurate rovibrational constants are deduced for all of the mixed states, leading to deperturbed values for ν1, α1B, and α1C of 1004.68(2), 0.000713(2), and 0.000348(2)cm−1, respectively. The Be value is found to be 0.310820(2)cm−1, yielding an equilibrium bond length re of 141.7333(4)pm that is, within experimental uncertainty, identical to the value of 141.7339(3)pm reported previously for 34S18O3. With this work, precise and accurate spectroscopic constants have now been determined in a systematic and consistent manner for all the fundamental vibrational modes of the sulfur trioxide D3h isotopomeric forms 32S16O3, 34S16O3, 32S18O3, and 34S18O3.