Spectra of co2-n2 dimer in the 4.2 micron region: higher k-values for the fundamental, the intermolecular bend, and symmetry breaking of the intramolecular co2 bend

Barclay, A. J.

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https://hdl.handle.net/2142/107354 Copy

Description

Title

Spectra of co2-n2 dimer in the 4.2 micron region: higher k-values for the fundamental, the intermolecular bend, and symmetry breaking of the intramolecular co2 bend

Author(s)

Barclay, A. J.

Contributor(s)

• Moazzen-Ahmadi, Nasser
• McKellar, Bob

Issue Date

2020-06-25

Keyword(s)

Atmospheric science

Abstract

Infrared spectra of the CO$_2$-N$_2$ dimer are observed in the 4.2 micron region using a tunable infrared optical parametric oscillator to probe a pulsed slit jet supersonic expansion. Previous results for the fundamental band are extended to higher values of K$_a$. A combination band involving the lowest in-plane intermolecular bending mode is observed. This yields a value of 21.4 cm$^{-1}$, and represents the first experimental determination of an intermolecular mode for CO$_2$-N$_2$. This intermolecular frequency is at odds with the value of 45.9 cm$^{-1}$ obtained from a recent 4D intermolecular potential generated at CCSD(T)-F12/augmented correlation consistent triple zeta (aug-ccpVTZ) level.\footnote{S. Nasri, Y. Ajili, N.-E. Jaidane, Y.N. Kalugina, P. Halvick, T. Stoecklin, M. Hochlaf, J. chem. Phys. 142 (2015) 174301.}$^{,}$\footnote{M. Lara-Moreno, T. Stoecklin, P. Halvick, M. Hochlaf, Phys. Chem. Chem. Phys. 21 (2019) 3550.} In addition, two weak bands near 2337 cm$^{-1}$ are assigned to the CO$_2$ hot band transition ($v_1$, $v_2^{l_2}$, $v_3$) = (01$^1$1) $\leftarrow$ (01$^1$0). They yield a value of 2.307 cm$^{-1}$ for the splitting of the degenerate CO$_2$ $\nu_2$ bend into in-plane and out-of-plane components due to the presence of the nearby N$_2$.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

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http://hdl.handle.net/2142/107354

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