Transcript N2O-C2H2

S. Sheybani-Deloui, J. Norooz Oliaee, M. Rezaei, N. MoazzenAhmadi
Department of Physics and Astronomy
University of Calgary
A.R.W. Mckellar
Steacie Institute for Molecular Sciences
National Research Council of Canada
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Objectives
Theoretical Calculations
Observed Spectra
Experimental Rotational Constants
Inter-conversion Tunneling Motion in C2H2
dimer
Experimental Structure
N2O-C2H2
Near parallel structure
Cs symmetry 1
OCS-C2H2
Near parallel structure
Cs symmetry 2
1. M. Dehghany, Mahin Afshari, J. Norooz Oliaee, N. Moazzen-Ahmadi, A.R.W. McKellar, Chemical Physics
Letters 473, 26 (2009).
2. J. Norooz Oliaee, Mahin Afshari, M. Dehghany, N. Moazzen-Ahmadi, A.R.W. McKellar, Journal of
Molecular Spectroscopy 157,133 (2009).
• Lowest
energy
isomers
• Planar
structures
• Cs symmetry
Second
Lowest
energy
isomers
• Loose barrel
Shape
structures
•
a
b
c
d
J. Norooz Oliaee, A.R.W. McKellar. N. Moazzen-Ahmadi, Chemical Physics Letters, 512(2011), p.167.
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Lowest energy minima of N2O-(C2H2)2
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Observed Planar Structure
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Second lowest energy minima
-1496 cm-1
E/cm-1
-1496
A/MHz
3142
B/MHz
1075
C/MHz
801
0.000002
-1414 cm-1
E/cm-1
-1414
A/MHz
2174
B/MHz
1788
C/MHz
1229
-103.8238
Theoretical Values:
R(10,1)
5.03530 (Å)
R(5,1)
3.29215 (Å)
A(5,1,2)
85.331˚
A(6,5,1)
100.313˚
A(10,1,2)
27.402˚
A(11,10,1)
33.106˚
Experimental Setup
Gas Supply
Jet
Trigger
Valve Controller
(Iota One)
IR Detectors
QCL
Jet Signal
PZT Controller
Ref. Gas
Function
Generator
Timer Controller
Card (CTR05)
Etalon
DAQ
Trigger
12 bit
DAQ Card
2232.81244(6)
Multiplied by 2
A”/MHz
B”/MHz
C”/MHz
A'/MHz
B'/MHz
C'/MHz
9.1
Inertial
defect/Amu. Å 2
0.000002
2233.0098(4)
Multiplied by 2
A”/MHz
B”/MHz
C”/MHz
A'/MHz
B'/MHz
C'/MHz
9.2
Inertial
defect/Amu. Å 2
0.000002
2163.40845(7)
Multiplied by 2
A”/MHz
B”/MHz
C”/MHz
A'/MHz
B'/MHz
C'/MHz
8.3
Inertial
defect/Amu. Å 2
0.000003
Rotational
Constants
Experimental data
(MHz)
Theoretical data
(MHz)
Cal.-Exp.
(MHz)
A (N2O-(C2H2)2)
2871.42438(1)
3142.08003
270.65565
B (N2O-(C2H2)2)
1140.67569(0.2)
1075.03097
-65.64472
C (N2O-(C2H2)2)
816.45943(0.1)
800.98280
-15.47663
A (N2O-(C2D2)2)
2689.66719(1.8)
2937.22521
247.55802
B (N2O-(C2D2)2)
1072.88785(0.1)
1011.54576
-61.34209
C (N2O-(C2D2)2)
767.58642(0.09)
752.42088
-15.16554
A (15N2O-(C2H2)2)
2837.05187(5.9)
3092.26268
251.21081
B (15N2O-(C2H2)2)
1114.90533(0.1)
1067.40500
-47.50033
C (15N2O-(C2H2)2)
801.95108(0.2)
793.50009
-8.45099
𝐸0 α 0 α
α 𝐸0 α 0
Eigenvalues of 𝐻 =
0 α 𝐸0 α
α 0 α 𝐸0
𝐸1 𝐴+ = 𝐸0 , 𝐸2 𝐴1 + = 𝐸0 − 2𝛼, 𝐸3 𝐵1 + = 𝐸0 + 2𝛼
𝐸 is a degenerate energy level, so:
Tunneling
Motion
~33 cm-1
Experimental
Values:
B(10,1)
4.79±0.01 (Å)
B(5,1)
3.97± 0.03(Å)
A(5,1,2)
74˚±5˚
A(6,5,1)
?
A(10,1,2)
28˚±5˚
A(11,10,1)
?
Experimental Structure Theoretical Structure
B(10,1)
4.79±0.01(Å)
5.035(Å)
B(5,1)
3.97± 0.03(Å)
3.292(Å)
A(5,1,2)
74˚±5˚
85.331˚
A(6,5,1)
?
100.31˚
A(10,1,2)
27˚±5˚
27.401˚
A(11,10,1)
?
33.106˚
K. H. Michaelian
Natural Resources Canada,
CANMET Western Research Center