University of Illinois Urbana-Champaign

Jet-cooled high resolution infrared laser spectroscopy of Kr-H2O in the region of the bending mode of H2O

Asselin, Pierre

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https://hdl.handle.net/2142/104280

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Title
Jet-cooled high resolution infrared laser spectroscopy of Kr-H2O in the region of the bending mode of H2O
Author(s)
Asselin, Pierre
Contributor(s)
  • Berger, Yann
  • Belkhodja, S.
Issue Date
2019-06-19
Keyword(s)
Non-covalent interactions
Date of Ingest
  • 2019-07-15T22:16:34Z
  • 2020-01-25T19:30:48Z
Abstract
The high sensitivity of our experimental setup (SPIRALES) [1] which couples an external cavity quantum cascade laser tunable from 1620 to 1690 \wn to a pulsed jet enabled the recording of a series of rovibrational transitions of Kr-H$_{2}$O van der Waals (vdW) complex. As for the Ar-H$_{2}$O complex [2], the barriers to internal rotation in the Kr-H$_{2}$O complex states are comparable to the H$_{2}$O rotational constants and so the H$_{2}$O subunit behaves like a nearly free internal rotor [3]. The quantum number K is used for describing the projection of J onto the vdW axis, with K = 0 for $\Sigma$, K = 1 for $\Pi$, etc. A previous jet-cooled microwave study [4] evidenced that the ground vibrational state involves 2 internal rotor states corresponding to different spin modifications, namely a para state $\Sigma($0$_{00}$) and an ortho state $\Sigma($1$_{01}$). The present work reports the observation of two new bands around 1634.5 \wn and 1659.7 \wn which can be interpreted according to a pseudo-atomic model. By analogy with Ar-H$_{2}$O bands observed in the same regions [2], the Kr-H$_{2}$O ones are tentatively assigned to para $\Pi$(1$_{11}$) $\leftarrow$ $\Sigma$(0$_{00}$) and ortho $\Pi$(2$_{12}$) $\leftarrow$ $\Sigma$(1$_{01}$) transitions, respectively, confirmed by the presence of Q branches. The ortho band displays strongly unequal spacings characteristic of a Coriolis coupling between $\Sigma$ and $\Pi$ states in vibrational excited states. \begin{wrapfigure}{c}{0pt} \includegraphics[scale=0.3]{H2O_Kr_1658_1661_Fig_abstractURB.eps} \end{wrapfigure} Moreover the high resolution achieved with the SPIRALES set-up allowed the observation of several isotopes of Kr. The analysis of these two bands and further investigations in the 1580-1620 \wn region are undergoing. References : [1] P. Asselin , A. Potapov, A. C. Turner, V. Boudon, L. Bruel, M.-A. Gaveau, M. Mons. PCCP 19, 17224-17232 (2017). [2] X. Liu , Y. Xu. J. Mol. Spectr. 301, 1-8 (2014). [3] R.C. Cohen , K . L . Busarow , Y. T. Lee, R. J. Saykally. JCP, 92, 169-177 (1990). [4] J. Van Wijngaarden, W. Jäger. Mol. Phys. 98, 19,1575-1588 (2000).
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
eng
Permalink
http://hdl.handle.net/2142/104280
DOI
https://doi.org/10.15278/isms.2019.WH01
Copyright and License Information
Copyright 2019 Pierre Asselin

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Abstracts & Presentations - 2019 International Symposium on Molecular Spectroscopy PRIMARY