Fermi Coupling and l-Type Resonance Effects in the Hot Bands of Acetylene: The 2650-cm−1 Region

✍ Scribed by R. Dcunha; Y.A. Sarma; V.A. Job; G. Guelachvili; K.N. Rao

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 488 KB
• Volume: 157
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1993.1028

✦ Synopsis

The hot bands originating from the low-lying (\nu_{4}\left(I_{g}\right)) state to the (\nu_{3}\left(\Sigma_{u}^{+}\right))fundamental and ( (\nu_{2}) (\left.+v_{4}+v_{5}\right)^{2,0 \pm}\left(\Sigma_{u}^{+}, \Sigma_{u}^{-}, \Delta_{u}^{e / /}\right)) combination states of acetylene have been analyzed in the highresolution FTIR spectrum recorded in the (2600-\mathrm{cm}^{-1}) region. Fermi resonance between the (\nu_{3}\left(\Sigma_{u}^{+}\right))and (\left(\nu_{2}+\nu_{4}+\nu_{5}\right)^{0}\left(\Sigma_{u}^{+}\right))levels, as well as the (l)-type resonances within the combination state, have been explicitly taken into consideration in the analysis of the data. Transitions to all the sublevels within the combination state as well as to the (\nu_{3}) state have been identified, and the data have been fitted with an overall standard deviation of (1.8 \times 10^{-4} \mathrm{~cm}^{-1}). Values for the perturbation parameters as well as deperturbed values for the band origins and rotational and centrifugal distortion constants are reported. «c 1993 Academic Press. Inc