ROTATIONAL SPECTROSCOPY AS A TOOL TO INVESTIGATE INTERACTIONS BETWEEN VIBRATIONAL POLYADS IN SYMMETRIC TOP MOLECULES: LOW-LYING STATES v8 ﾲ 2 OF METHYL CYANIDE

Müller, Holger S.P.

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https://hdl.handle.net/2142/79284 Copy

Description

Title

ROTATIONAL SPECTROSCOPY AS A TOOL TO INVESTIGATE INTERACTIONS BETWEEN VIBRATIONAL POLYADS IN SYMMETRIC TOP MOLECULES: LOW-LYING STATES v8 ﾲ 2 OF METHYL CYANIDE

Author(s)

Müller, Holger S.P.

Contributor(s)

• Sams, Robert
• Kleiner, Isabelle
• Sung, Keeyoon
• Pearson, John
• Drouin, Brian
• Brown, Linda
• Lewen, Frank
• Ordu, Matthias H.

Issue Date

26-Jun-15

Keyword(s)

Spectroscopy as an analytical tool

Abstract

Rotational and rovibrational spectra of methyl cyanide were recorded to analyze interactions in low-lying vibrational states and to construct line lists for radio astronomical observations as well as for infrared spectroscopic investigations of planetary atmospheres. The rotational spectra cover large portions of the 36$-$1627~GHz region.footnote{Part of this work was carried out at the Jet Propulsion Laboratory under contract with the National Aeronautics and Space Administration.} In the infrared (IR), a spectrum was recorded for this study in the region of $2nu_8$ around 717~cm$^{-1}$ with assignments covering 684$-$765~cm$^{-1}$. Additional spectra in the $nu _8$ region were used to validate the analysis. Using $nu _8$ datafootnote{M. Koivusaari et al., {it J. Mol. Spectrosc.} {bf 152} (1992) 377$-$388.} as well as spectroscopic parameters for $v_4 = 1$, $v_7 = 1$, and $v_8 = 3$ from previous studies,footnote{A.-M. Tolonen et al., {it J. Mol. Spectrosc.} {bf 160} (1993) 554$-$565.} we analyzed rotational data involving $v = 0$, $v_8 = 1$, and $v_8 = 2$ up to high $J$ and $K$ quantum numbers. We analyzed a strong $Delta v_8 = pm 1$, $Delta K = 0$, $Delta l = pm3$ Fermi resonance between $v_8 = 1^{-1}$ and $v_8 = 2^{+2}$ at $K = 14$ and obtained preliminary results for two further Fermi resonances between $v_8 = 2$ and 3. We also found resonant $Delta v_8 = pm 1$, $Delta K = mp 2$, $Delta l = pm 1$ interactions between $v_8 = 1$ and 2 and present the first detailed analysis of such a resonance between $v_8 = 0$ and 1. We discuss the impact of this analysis on the $v_8 = 1$ and 2 as well as on the axial $v = 0$ parameters and compare selected CH$_3$CN parameters with those of CH$_3$CCH and CH$_3$NC. We evaluated transition dipole moments of $nu _8$, $2nu _8 - nu _8$, and $2nu _8$ for remote sensing in the IR.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79284

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