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JET-COOLED LASER SPECTROSCOPY OF A JAHN-TELLER AND PSEUDO JAHN-TELLER ACTIVE
MOLECULE: THE NITRATE RADICAL (NO3)
1Laser Spectroscopy FacilityDepartment of ChemistryThe Ohio State University
6/23/2009
64th OSU International Symposium on Molecular Spectroscopy
2Arthor Amos Noyes Laboratory of Chemical Physics
California Institute of Technology
MING-WEI CHEN1, KANA TAKEMATSU2, MICHIO OKUMURA2 and TERRY A. MILLER1
Outline
Introduction Motivation and aims
Spectroscopy Geometry and vibronic coupling Spectroscopic review
Experiment Apparatus of NO3 measurement Initial results of NO3
Future works
Introduction Motivation and aims
Spectroscopy Geometry and vibronic coupling Spectroscopic review
Experiment Apparatus of NO3 measurement Initial results of NO3
Future works
NO3 in Atmosphere
NO3
NO2
N2O5
-NO2
-NO2, hν
+NO2hν-OO3
HNO3
hydrometeors
In troposphere
R. P. Wayne et al., Atmos. Envir. 25A, 1 (1991).
Nitrate radical (NO3) is an important radical intermediate in the night-time atmosphere, involved in the chemical transformations in both the stratosphere and the troposphere.
J.A. Logan, J. Geophys. Res. 86, 7210 (1983).
Mix
ing
Rat
io
10-10
10-11
10-12
10-13
10-14
hν
NO
-O
RO2
RO
NO NO2
RO2
TF08TF09TJ08RD05
RO
WJ10
Reactions of Radicals
RO2
OH
R’CHO
RO
RH
RO2NO2
RONO2
HO2
CO
CO2
R’C(O)O2
PAN
ROOH
O2
NO2HO2
NONO
hn
OH NO2
NO NO2
hn
OH
O2
O2
NO2
NO
DIsomerisation
Multistep
hn
NO2
O2
RO2
RO
NO3 NO2
RO2
RO
NO3
Day time
Night time
ONONO
NORONOROh
2
22
2332
2232
ONOONO
ONORONORO
R. P. Wayne et al., Atmos. Envir. 25A, 1 (1991).
Lightfoot et. al. Atmos. Envir. 26A, 1805 (1992). hν
O3
Motivations and Aims
The three energetically lowest states are coupled by vibronic interaction, and therefore a model molecule for understanding the coupling between nearby potential energy surfaces and the Jahn-Teller (JT)/pseudo Jahn-Teller (PJT) effects
Comprehensive understand of the molecular structure with LIF/SEP experiment and benchmark for ab initio calculations of NO3
M. Okumura J. F. Stanton, A. Deev and J. Sommar, Phys. Scr., 73, C64 (2006).
Vibronic Coupling (Linear)
aQ
U
bQ
aQ
U
bQ
Linear JT Pseudo JT
2/1221
21
2202
1 baba QkQkQQkU 2/122
122
02
1baba QQkQQkU
aQ
U
bQ
aQ
U
bQ
''~2EA
or
'~2EB
'~
22AX
''~2EA or '
~2EB
Quadratic JT/PJT Coupling
N
O
O O
D3h
C2v
.
.
.
.
.
.
Spectroscopy of Nitrate Radicals
NO3─
NO3 + e─
.
.
.
'~
22AX
"~2EA
'~2EB
MIR NIR
LEDF
PDSLIF
Absorption
Vis
NO3 + e─
• T. Ishiwata, I. Tanaka, K. Kawaguchi, and E. Hirota, J. Chem. Phys., 82, 2196 (1985).
• R. R. Fredl and S. P. Sander, J. Phys. Chem., 91, 2721 (1987).• E. Hirota, K. Kawaguchi, T. Ishiwata, and I. Tanaka, J. Chem. Phys., 95, 771 (1991).• K. Kawaguchi, T. Ishiwata, I. Tanaka, and E. Hirota, Chem. Phys. Lett., 180, 436
(1991).• T. Ishiwata, I. Tanaka, K. Kawaguchi, and E. Hirota, J. Mol. Spec., 183, 167 (1992).
• E. Hirota, T. Ishiwata, K. Kawaguchi, M. Fujitake, N. Ohashi, and I. Tanaka, J. Chem. Phys., 107, 2829 (1997).
• K. Kawaguchi, T. Ishiwata, E. Hirota, and I Tanaka, Chem. Phys., 231, 193 (1998).• A. Deev, J. Sommar, and M. Okumura, J. Chem. Phys., 122, 224305/1 (2005).• M. Jacox and W. E. Thompson, 64th International Symposium on Molecular
Spectroscopy, TF12 (2009).
• D. A. Ramsay, Proc. Colloq. Spectrosc. Int., 10, 583 (1962).• W. J. Marinelli, D. M. Swanson, and H. S. Johnston, J. Chem. Phys., 76, 2864
(1982).• M. Jacox and W. E. Thompson, 64th International Symposium on Molecular
Spectroscopy, TF12 (2009).
• T. Ishiwata, I. Fujiwara, Y. Naruge, K. Obl, and I. Tanaka, J. Chem. Phys., 87, 1349 (1983).
• B. Kim, P. L. Hunter, and H. S. Johnston, J. Chem. Phys., 96, 4057 (1992).• R. T. Carter, K. F. Schmidt, H. Bitto, and J. R. Huber, Chem. Phys. Lett., 257, 297
(1996).• L. Valachovic C. Riehn, K. Mikhaylichenko and C. Wittig, Chem. Phys. Lett., 258,
644 (1996).
• A. Weaver, D. W. Arnold, S. E. Bradforth, and D. M. Neumark, J. Chem. Phys., 94, 170 (1991).
Vibronic Selection Rules
22X A
2B E
2A E
Pump
DumpT0(cm-1)
15089
7064
0
ΔE = 8025 cm-1
Electronic States and Transitions
(Forbidden)
CH3O LIF/SEP Spectra
32892 32894 32896 32898 32900 32902 32904-25
-20
-15
-10
-5
0
5
32894.0 32894.1
-8
-6
-4
-2
0
2
P2b
pumped, moderate-resolution dump
P2a
pumped, moderate-resolution dump
32892 32894 32896 32898 32900 32902 32904-25
-20
-15
-10
-5
0
5
Dep
letio
n R
ate
(%)
32898.6 32898.7 32898.8
Dump Frequency / cm -1
32901.5 32901.6
P2a
+P2b
pumped, high-resolution dump
~2
3/2EX
~2
1AA
~2
1/2EX
LIF
SEP
32950 32955 32960 32965 32970 32975 32980
wavenumbers / cm-1
P2
J. Liu, M.-W. Chen, D. Melnik, J. T. Yi and T. A. Miller, J. Chem. Phys., 130, 074302 (2009)
pulse
continuous
Jet
Excitation laser beam
Schematic Diagram of LIF Detection
N2O5 with He/Ne mixture
3252 NONOON
Dump laser beam
Heated nozzle tip
LIF of NO3 Origin Band
L. Valachovic C. Riehn, K. Mikhaylichenko and C. Wittig, Chem. Phys. Lett., 258, 644 (1996).
15000 15050 15100 15150 15200 15250 15300
wavenumbers / cm-1
NO3 LIF spectrum, continuous flow.
Moderate-res.a
LIF of NO3 Origin Band
15100 15110 15120 15130 15140
wavenumbers / cm-1
FWHM ~ 0.19(7) cm-1
cw jet, scan step: 0.23 cm-1
pulse jet, scan step: 0.05 cm-1
bR. T. Carter K. F. Schmidt, H. Bitto and J. R. Huber, Chem. Phys. Lett., 257, 297 (1996).
High-res.b
aL. Valachovic C. Riehn, K. Mikhaylichenko and C. Wittig, Chem. Phys. Lett., 258, 644 (1996).
Summary and Future Works
Summary: Apparatus with both high-resolution
(FWHM~250MHz) and high-accuracy (σ~50MHz) for LIF and SEP measurements.
Preliminary NO3 LIF of origin band has been obtained.
Future works: Optimize the system to improve the
quality of the LIF spectrum. Measure the SEP spectra of and
transitions.
Summary: Apparatus with both high-resolution
(FWHM~250MHz) and high-accuracy (σ~50MHz) for LIF and SEP measurements.
Preliminary NO3 LIF of origin band has been obtained.
Future works: Optimize the system to improve the
quality of the LIF spectrum. Measure the SEP spectra of and
transitions.
XB~~
AB~~
XB~~
XB~~
.
.
.
'~
22AX
"~2EA
'~2EB
HR-LIF
HR-SEP
.
.
.
.
.
.
S. Kasahara, K. Kanazawa, Y. Semba, K. Yoshida, M Baba, T. Ishiwata and E. Hirota, 64th International Symposium on Molecular Spectroscopy, TJ07 (2009).
Acknowledgement
The Miller Group (OSU):
Dr. Miller
Dmitry Melnik (WJ10, RD05)
Phillip Thomas (TJ08)
Gabriel Just (TF08, TF09)
Rabi Chhantyal-Pun
Terrance Codd
Neal Klein Funding: NSFYour attention!
The Okumura Group (CIT):
Dr. Okumura
Kana Takematsu (WJ11, RD02)