University of Illinois Urbana-Champaign

Experimental insight on the conformational landscape of the SF6 dimer: Evidence for three conformers

Asselin, Pierre

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906490.pptx

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https://hdl.handle.net/2142/96871

Description

Title
Experimental insight on the conformational landscape of the SF6 dimer: Evidence for three conformers
Author(s)
Asselin, Pierre
Contributor(s)
  • Mons, Michel
  • Gaveau, Marc-André
  • Bruel, Laurent
  • Boudon, Vincent
  • Potapov, Alexey
Issue Date
2017-06-23
Keyword(s)
Clusters/complexes
Date of Ingest
  • 2017-07-27T20:15:07Z
  • 2018-01-29T23:04:13Z
Abstract
The rovibrational spectrum of both parallel and perpendicular bands of the chem{SF_6} dimer near the nub{3} band of chem{SF_6} monomer was reinvestigatedfootnote{R.-D. Urban and M. Takami, J. Chem. Phys. 103, 9132 (1995).} using high resolution jet-cooled infrared laser spectroscopy to provide deeper insight on its conformational landscape. Taking advantage of our versatile set-upfootnote{P. Asselin, Y. Berger, T. R. Huet, R. Motiyenko, L. Margulès, R. J. Hendricks, M. R. Tarbutt, S. Tokunaga, B. Darquié, PCCP 19, 4576 (2017).}, jet-cooled spectra were recorded by combining different geometries of supersonic expansions, chem{SF_6} concentrations seeded in a carrier gas and axial distances. Relaxation effects could be evidenced at very low rotational temperature leading to different conformational populations. Three spectral features (noted #1, #2 and #3) belonging to three dimer conformers are unambiguously identified on the grounds of 3 distinct S-S distances derived from the rovibrational analysis of parallel band contours in the 932-935 wn range. Symmetry assignment, a priori accessible from the perpendicular band structure of a spherical top dimer, could not be clearly proved. The dependence of such conformational infrared signatures as a function of expansion conditions provides additional information about population dependence and interconversion processes taking place between these three forms predicted to be nearly isoenergetic by theoretical calculationsfootnote{T. Vazhappilly, A. Marjolin and K. J. Jordan, J. Phys. Chem. B 120, 1788 (2016).}. Based on experimental considerations, a qualitative picture of the nearly flat potential energy surface of the chem{SF_6} dimer is proposed which could explain the dominant presence of #1 and #3 populations in fast/cold axisymmetric expansions and that of #1 and #2 populations in slow/hot planar ones._x000d_ _x000d_
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
eng
Permalink
http://hdl.handle.net/2142/96871
DOI
https://doi.org/10.15278/isms.2017.FD05
Copyright and License Information
Copyright 2017 Pierre Asselin

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Abstracts & Presentations - 2017 International Symposium on Molecular Spectroscopy PRIMARY