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FTMW Observation OCS-CS 2 dimer: Previous Work ORIENT Semi-Empirical Modeling ORIENT Semi-Empirical Modeling 3/11
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Infrared spectroscopy of two isomers of the OCS-CS2 complex
J. Norooz Oliaee, M. Dehghany, Mahin Afshari, N. Moazzen-AhmadiDepartment of Physics and Astronomy, University of Calgary
A. R. W. McKellarSteacie Institute for Molecular Sciences, National Research Council of Canada
OutlinePrevious work on OCS-CS2
Our recent work on OCS-CS2
Comparison with similar species OCS-CO2
CO2-CS2
Summary
2/11
FTMW
Observation
OCS-CS2 dimer: Previous Work
ORIENT
Semi-Empirical Modeling
ORIENT
Semi-Empirical Modeling3/11
2057.6 2057.8 2058.0 2058.2
wavenumber/cm-1
Experiment
Simulation
OCS-CS2 dimer: Our recent workInfrared observation of the lowest-energy isomer of OCS-CS2 at ~ 2057.91 cm-1
Structure I
Cs symmetryPlanar
a- and b-type@ ~ 2057.91 cm-1
Blank regions indicate OCS absorption lines. 4/11
2059.4 2059.6 2059.8 2060.0
wavenumber/cm-1
Experiment
Total
OCS-CS2-Crossed
OCS-CS2-parallel
He-OCS
Infrared observation of the intermediate-energy isomer of OCS-CS2 at ~ 2060.07 cm-1
Blank regions indicate OCS absorption lines.
Structure II
Cs symmetryNon-planar
Predominantly c-type@ ~2060.07 cm-1
OCS-CS2 dimer: Our recent work
Sid
e
view
Top
view
5/11
a
c
b
Structure of the intermediate-energy isomer of OCS-CS2
Structure II
Cs symmetryNon-planar
Predominantly c-type@ ~2060.07 cm-1q
RCM
Rotational and Structural Parameters Comparison Table
A/MHz B/MHz C/MHz RCM /Å q/ ° Dihedral/ °
Peebles’ Group* 2138 1029 898 3.490 84.8 90.0
Our Group 2187.7(4.5) 997.8(1.8) 864.13(33) 3.5578(17) 74.89(46) Crossed
* Semi-empirical modelling by ORIENT program
OCS-CS2 dimer: Our recent work
6/11
Comparison with similar species:OCS-CO2 dimer: previous studies
FTMW observation of the planar S-interior slipped near-parallel OCS-CO2 dimer
ab initio calculations for O-interior slipped near-parallel OCS-CO2 dimer
7/11
Comparison with similar species:OCS-CO2 dimer: Our recent studies
Isomer a structural parametersRCM /Å q1/ ° q2 / °
Novick et al*
3.552(3) 68.94(30) 78.93(57)
Our Group 3.5545(10) 69.7(4) 78.7(3)
Isomer b structural parametersRCM /Å q1/ ° q2 / °
Valdes et al†
3.913 122.45 131.05
Our Group
3.9862(10) 118.0(5) 135.8(3)* FTMW observation† ab initio calculations at the MP2/cc-pVTZ level
@ 2066.1 cm-1 @ 2055.7 cm-1
8/11
Comparison with similar species:CO2-CS2 dimer: previous studies
Cross-shaped@ ~ 2346.55 cm-1
withRCM=3.392 (Å)
9/11
Lowest-energy isomer
Intermediate-energy isomer
Highest-energy isomer
OCS-CS2
OCS-CO2
CO2-CS2
Summary
MW1
IR IR
MW2
IR3
IR3
MW4
IR
1 Josh J. Newby et al, Phys. Chem. Chem. Phys. 7, 487-492 (2005)2 Stewart E. Novick et al, J. Chem. Phys. 88, 687 (1988)3 M. Dehghany et al, J. Chem. Phys. 130, 224310 (2009)4 C. C. Dutton et al, J. Phys. Chem. A 102, 6904-6909 (1998)
10/11
Thanks for your attention!
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