The Infrared Spectrum of Methyl Cyanide Between 1240 and 1650 cm−1: The Coupled Band System ν3, ν±16, and ν7 + ν±28

✍ Scribed by R. Paso; R. Anttila; M. Koivusaari

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 545 KB
• Volume: 165
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1994.1150

✦ Synopsis

A Fourier transform spectrum with a resolution of (0.002 \mathrm{~cm}^{-1}) of (\mathrm{CH}{3} \mathrm{CN}) has been studied in the spectral region of 1240-1650 (\mathrm{cm}^{-1}). The region covers the bands (\nu{3}, \nu_{6}^{ \pm 1}), and (\nu_{7}+\nu_{8}) which are coupled by very strong Fermi and Coriolis interactions. More than 3900 lines were assigned in the spectrum, mostly to the bands (\nu_{6}^{ \pm 1}) and (v_{7}+\nu_{8}^{ \pm 2}). The rotational structure of these bands including the (Q) branches was almost completely resolved. The PAPE component of (\nu_{7}+\nu_{8}) was not detected. For the weak (\nu_{3}) band, which has not been observed earlier directly, we were able to assign the two subbands (K=5) and 6 around the (\nu_{3} / \nu_{6}) Coriolis resonance crossing region. A least-squares fit with 42 parameters and about 20 interactions led to a standard deviation of 0.0072 (\mathrm{cm}^{-1}). C 1994 Academic Press. Inc.