THE 4.2 MICRON SPECTRA OF CO2-CO DIMER FOR BOTH THE C- AND O-BONDED ISOMERS, INCLUDING SPLITTING OF THE DEGENERATE ν2 BEND IN THE PRESENCE OF CO

Wakwella, Praveen

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https://hdl.handle.net/2142/107700 Copy

Description

Title

THE 4.2 MICRON SPECTRA OF CO2-CO DIMER FOR BOTH THE C- AND O-BONDED ISOMERS, INCLUDING SPLITTING OF THE DEGENERATE ν2 BEND IN THE PRESENCE OF CO

Author(s)

Wakwella, Praveen

Contributor(s)

Moazzen-Ahmadi, Nasser ; McKellar, Bob ; Barclay, A. J.

Issue Date

22-Jun-20

Keyword(s)

Non-covalent interactions

Abstract

Infrared spectra of the CO$_2$-CO dimer are observed in the carbon dioxide $\nu_3$ asymmetric stretch region ($\sim$2350 cm$^{-1}$) using a tunable infrared optical parametric oscillator to probe a pulsed slit jet supersonic expansion. Both C-bonded and O-bonded isomers are analyzed for the normal isotopologue as well as for $^{13}$CO$_2$-CO and $^{16}$O$^{13}$C$^{18}$O-CO, the latter being the first observation of an asymmetrically substituted form for which all values of K$_a$ are allowed. A combination band involving the lowest in-plane intermolecular mode ($\sim$24.5 cm$^{-1}$) is also studied for the C-bonded form. A weak band near 2337 cm$^{-1}$ is assigned to the CO$_2$ hot band transition ($v_1$, $v_2^{l_2}$, $v_3$) = (01$^1$1) $\leftarrow$ (01$^1$0), yielding the splitting of the degenerate CO$_2$ $\nu_2$ bend into in-plane and out-of-plane components due to the presence of the CO. The splitting, an aspect of intermolecular forces which has received little attention in the past, has rather different values of 4.56 and 1.59 cm$^{-1}$ for the C- and O- bonded isomers, respectively.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

English

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http://hdl.handle.net/2142/107700

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