High resolution infrared studies of the ν2,ν4 bands of 34S16O3, including both intensity and wavenumber perturbations

✍ Scribed by Jeffrey Barber; Tony Masiello; Engelene t.H. Chrysostom; Joseph W. Nibler; Arthur Maki; Alfons Weber; Thomas A. Blake; Robert L. Sams

• Book ID: 104151725
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 209 KB
• Volume: 218
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1016/s0022-2852(02)00051-6

✦ Synopsis

The infrared spectrum of the m 2 ; m 4 bending mode region of 34 S-substituted sulfur trioxide, 34 S 16 O 3 , has been recorded at a resolution of 0:0025 cm À1 . The m 2 and m 4 levels are coupled by a Coriolis interaction, yielding significant spectral shifts that have been successfully analyzed to obtain rovibrational constants for the ground state and both fundamentals. Comparisons are made with 32 S 16 O 3 parameters and the B 0 rotational constant is found to be 0.348 556 03(28) cm À1 , only very slightly larger than the corresponding value of 0.348 543 33(5) cm À1 for 32 S 16 O 3 . Coriolis and l-type resonance interactions between the m 2 and m 4 levels produce frequency shifts and strong intensity perturbations in the spectra that are considered for both 34 S 16 O 3 and 32 S 16 O 3 . The resulting analysis yields an average value of AE0:62ð8Þ for the dipole derivative ratio ðol x =oQ 4x Þ=ðol z =oQ 2 Þ and a positive sign for the product of this ratio with the f y 2;4 Coriolis constant, for which experiment gives AE0:5940ð15Þ. Ab initio calculations indicate that the signs of ol x =oQ 4x and ol z =oQ 2 are both positive and hence f y 2;4 is also positive, in agreement with earlier calculations. These signs indicate that the effective charge movement in the xz plane has the same sense of rotation as Q 2 ; Q 4x atom motion in this plane that produces a p y vibrational angular momentum component, correlated motion that is confirmed by ab initio calculations.