OBSERVATION AND ANALYSIS OF THE $\nu_{3}$ and $2\nu_{3}$ BANDS OF $^{32}S^{18}O_{3}$ AND $^{34}S^{18}O_{3}$

$^{a}$ E. t.H. Chrysostom, N. Vulpanovici, T. Masiello, J. Barber, J. W. Nibler, A. Weber, A. Maki, T. A. Blake, J. Mol. Spectrosc. 210, 233 (2001). $^{b}$ A. Maki, T. A. Blake, R. L. Sams, N. Vulpanovici, J. Barber, E. t.H. Chrysostom, T. Masiello, J. W. Nibler, A. Weber, J. Mol. Spectrosc. 210, 240 (2001). (PNNL is operated for the US Department of Energy by the Battelle Memorial Institute under contract DE-AC06-76RLO 1830)Author Institution: Pacific Northwest National Laboratory; Department of Chemistry, Oregon State University; National Science Foundation, National Institute of Standards and TechnologyWe are engaged in a comprehensive investigation of the fundamental and low lying combination and overtone bands of the parent and some isotopic variants of sulfur trioxide. Results and analysis for the $Ramana^{a}$ and $infrared^{b}$ bands of the parent isotopomer have been published recently. Here, results and analysis of the infrared absorption spectra of the $\nu_{3}$ and $2\nu_{3}$ bands of $^{32}S^{18}O_{3}$ and $^{34}S^{18}O_{3}$ recorded separately at a resolution of $0.002 cm^{-1}$ will be presented. For $^{32}S^{18}O_{3}, \nu_{3}$ is centered at $1348.85320(3) cm^{-1}$ with $B^{\prime} = 0.30879466(7) cm^{-1}, C^{\prime} = 0.15436012(6) cm^{-1}$ and $C^{\prime}\zeta = 0.0795934(4) cm^{-1}$. The $l=\pm 2$ component of the first overtone of $\nu_{3}$ is centered at $2692.8899(3) cm^{-1}$ with $B^{\prime} = 0.307815(1) cm^{-1}, C^{\prime} = 0.1538331(7) cm^{-1}$ and $C'\zeta = 0.078716(2) cm^{-1}$. For $^{34}S^{18}O_{3}, \nu_{3}$ is centered at $1330.07810(1) cm^{-1}$ with $B' = 0.3088233(3) cm^{-1}$ and $C^{\prime} = 0.15437917(3) cm^{-1}$, and $C'\zeta = 0.0770680(3) cm^{-1}$. The $l = \pm 2$ component of the first overtone of $\nu_{3}$ is centered at $2655.45735(4) cm^{-1}$ with $B^{\prime} = 0.3078634(8) cm^{-1}, C^{\prime} = 0.15386494(7) cm^{-1}$ and $C^{\prime}\zeta = 0.0762487(3) cm^{-1}$. The Hamiltonian for analyzing these bands including splitting and perturbing terms and other fit constants will be presented