~ ~
JET-COOLED A-X SPECTRA OF THE βHYDROXYETHYLPEROXY RADICAL AND ITS
ISOTOPOLOGUES
MING-WEI CHEN, GABRIEL M. P. JUST*, TERRANCE J. CODD
and TERRY A. MILLER
Laser Spectroscopy Facility
Department of Chemistry
The Ohio State University
*
Current affiliation: Lawrence Berkeley National Laboratory
6/21/2010
 Importance of the β-HEP has
been presented in MI07*.
G1G2G3
40
 Conformer assignment on RT
spectrum is only on the basis
of vibronic analysis.*
35
30
ppm
25
 Information from the jetcooled spectrum:
20
15
10
5
7200
7300
7400
7500
wavenumber / cm
7600
-1
7700
 Obtain the rotational constants
from the jet-cooled spectrum of
the 7381 cm-1 band found in RT
CRDS.
 Check the geometry from
experiment and compare with
the ab initio calculation.
*See also: R. Chhantyal-Pun, N. D. Kline, P. S. Thomas and T. A. Miller J. Phys. Chem. Lett., 1, 1846 (2010)
Diode laser
(CW)
Nd:YAG
(20Hz)
λ/2
P
Ti:Sa Ring
(CW)
BD
OI
45- 100 mJ / pulse
Δν (FWHM) ∼ 7 - 30 MHz
(FT limited)
BS
BS
Ti:Sa
Ti:Sa
OC
BS
BS
PZT
Driver
PD
BS
BD
45- 100 mJ / pulse
Δν (FWHM) ∼ 7 - 30 MHz
(FT limited)
1st stokes ∼ 1.3 μm ∼ 4 mJ
Δν ∼ 200 MHz
(limited by pressure broadening in H2)
InGaAs
Detector
67 cm
BBO ∼ 1.3 μm ∼ 2mJ
Δν ∼ 70 MHz (measured)
+ O2
Viton Poppet
5 mm
9 mm
Electrode
Electrode
5 cm
10 mm
IR Beam
-HV
Previous similar slit-jet designs:
D.J. Nesbitt group, Chem. Phys. Lett. 258, 207 (1996)
R.J. Saykally group, Rev. Sci. Instrum. 67, 410 (1996)
T. A. Miller group, Phys. Chem. Chem. Phys. 8, 1682 (2006).
• radical densities of 1012 - 1013 molecules/cm3 (10 mm downstream, probed)
• rotational temperature of 15 - 30 K (residual ΔνDoppler ~155MHz at 20K)
• plasma voltage ~ 500 V, I  1 A (~ 400 mA typical), 100 µs length
• dc and/or rf discharge, discharge localized between electrode plates,
increased signal compared to longitudinal geometry
16
16
14
Δνspectral~250MHz
(measured with SRS, residual ΔνDoppler ~155MHz)
14
12
ppm/pass
10
12
8
6
10
2
0
-2
7590
7595
7600
ppm/pass
4
excitation energy / cm
8
6
7605
7610
-1
4
2
0
-2
7605
7606
7607
excitation energy / cm
NO3 talk on Wednesday: WJ04
-1
7608
Jet-cooled experimental data
Specview simulation (asymmetric top)
assuming Δν=250MHz, rotational constants
are from MP2(Full)/6-31G* optimized
geometry.
4
2
1
4
3
0
ppm/pass
ppm/pass
3
2
1
-1
0
7380
7385
7390
excitation energy / cm
7395
-1
-1
7388.0
7400
7388.2
7388.4
7388.6
excitation energy / cm
7388.8
-1
7389.0
5
β-HEP
4
ppm / pass
3
2
1
0
-1
7380
7385
7390
7395
excitation energy / cm
7400
-1
H
D
S. Wu, P. Rupper, P. Dupré and T. A. Miller, 62nd International Symposium on Molecular Spectroscopy, RF09 (2007)
ICH2CH2OD (Not commercially available)
I
H
I
H
H
H
+D2O
C
C
C


C
H
H
H
HO
H
DO
Band origin shifts.
Better resolved rotational
contour.
DOCH2CH2OO
DOCH2CH2OO
HOCH 2CH2OO
HOCH 2CH2OO
7380
7385
7390
excitation energy / cm
7395
7400
-1
7388
7390
7392
excitation energy / cm
7394
-1
DOCD2CD2OO
β-DHEP-d4
β-DHEP
DOCH2CH2OO
β-HEP-d4
HOCD2CD2OO
β-HEP
HOCH 2CH2OO
7380
7385
7390
7395
excitation energy / cm
7400
-1
Isotope shifts observed among four
different isotopologues. Confirming
four different species observed in the
experiments.
Similar overall rotational contours
for all four spectra, showing four
measured species are having similar
structure.
7405
β-DHEP-d4
DOCD2CD2OO
β-DHEP
DOCH2CH2OO
β-HEP-d4
HOCD2CD2OO
β-HEP
HOCH 2CH2OO
7386
7388
7390
7392
7394
excitation energy / cm
Upper = exp. data
Lower = simulation from EA analysis
Rotational constants and Lorentzian
linewidth (ΔνL) are obtained for each
isotopologue by evolutionary
algorithm.
7396
-1
G. M. P. Just, P. Rupper, T. A. Miller and W. L. Meerts J. Chem. Phys., 131, 184303 (2009)
G. M. P. Just, P. Rupper, T. A. Miller and W. L. Meerts Phys. Chem. Chem. Phys., 12, 4773 (2010)
HOCH2CH2O2
DOCH2CH2O2
HOCD2CD2O2
DOCD2CD2O2
EA fit
MP2 **
EA fit
MP2**
EA fit
MP2**
EA fit
MP2**
-1
-1
-1
-1
-1
-1
-1
value(cm ) (2.5σ) value(cm ) value(cm ) (2.5σ) value(cm ) value(cm ) (2.5σ) value(cm ) value(cm ) (2.5σ) value(cm-1)
ground
A
B
C
0.29282 (125)
0.14014 (94)
0.10125 (81)
0.29721
0.13839
0.10362
0.28629 (26)
0.13655 (19)
0.10137 (18)
0.28824
0.13754
0.10206
0.24645 (63)
0.12604 (63)
0.09930 (63)
0.25049
0.12902
0.09699
0.24222 (13)
0.12720 (13)
0.09440 (13)
0.24329
0.12840
0.09557
excited
T 00
A
B
C
T ROT (K)
7389.085
0.28238
0.14409
0.10115
26.16
Δν L (MHz)
7442
|μ b /μ a |
0.528
|μ c /μ a |
0.338
(33)
(125)
(100)
(81)
7355.69
0.28517
0.14173
0.10393
..
7391.846
0.27610
0.13857
0.10158
18.14
(3)
(25)
(19)
(18)
7355.47
0.27617
0.14072
0.10231
..
7390.35
0.24037
0.12602
0.09960
18.25
..
3469
..
7878
(fixed)
0.844 *
0.552
0.844 *
0.558
(fixed)
1.46 *
0.340
1.46 *
0.336
(70)
(63)
(63)
(63)
7357.45
0.24277
0.13145
0.09690
..
7392.740
0.23379
0.13044
0.09426
22.53
(18)
(13)
(19)
(13)
7357.23
0.23540
0.13073
0.09542
..
..
2472
..
(fixed)
0.844 *
0.541
0.844 *
(fixed)
1.46 *
0.307
1.46 *
*Theoretical electronic dipolemements are calculated by UCIS/6-31G*
**ab initio calculated rotational constants are from the MP2(full)/6-31G*optimized geometry.
 L FWHM  
Natural linewidth
ΔνL=7442 MHz*
~21 ps
ΔνL=7878 MHz*
~20 ps
1
2
ΔνL=3469 MHz*
~46 ps
ΔνL=2472 MHz*
~64 ps
Excited state lifetime (τ) of β-HEP : ~20ps
*1σ of EA estimated ΔνL is ~225MHz
16000
14000
energy / cm
-1
12000
10000
8000
7206cm-1 c)
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
a)
b)
16000
First excited state energies
calculated by TD DFT/6311++G(d,p)
14000
energy / cm
-1
12000
10000
8000
7206cm-1 c)
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
a)
b)
16000
First excited state energies
calculated by TD DFT/6311++G(d,p), shifted to
~ ~
match the A-X experimental
excitation energy of β-HEP.
14000
energy / cm
-1
12000
ΔEethoxy~355 cm-1 f)
10000
8000
~7389 cm-1 e)
7206cm-1 c)
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
e) Present jet-cooled data.
f) See TG14.
a)
b)
16000
First excited state energies
calculated by TD DFT/6311++G(d,p), shifted to
~ ~
match the A-X experimental
excitation energy of β-HEP.
14000
energy / cm
-1
12000
ΔEethoxy~355 cm-1 f)
10000
8000
~7389 cm-1 e)
7206cm-1 c)
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
e) Present jet-cooled data.
f) See TG14.
a)
b)
16000
First excited state energies
calculated by TD DFT/6311++G(d,p), shifted to
~ ~
match the A-X experimental
excitation energy of β-HEP.
14000
energy / cm
-1
12000
10000
ΔEethoxy~355 cm-1 f)
~7389 cm-1 e)
8000
7206cm-1 c)
I.C.
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
e) Present jet-cooled data.
f) See TG14.
a)
b)
16000
First excited state energies
calculated by TD DFT/6311++G(d,p), shifted to
~ ~
match the A-X experimental
excitation energy of β-HEP.
14000
energy / cm
-1
12000
10000
ΔEethoxy~355 cm-1 f)
~7389 cm-1 e)
I.C.
8000
7206cm-1 c)
6000
4000
2000
0
Ground state barrier (+ZPE)a)-d): 6160-10530 cm-1
rxn. coordinate
S. Olivella, A. Solé, J. Phys. Chem. 108, 11651 (2004)
K. T. Kuwata, T. S. Dibble, E. Sliz, E. B. Peterson, J. Phys. Chem. A, 111, 5032 (2007)
c) J. Zádor, R. X. Fernandes, Y. Georgievskii, G. Meloni, C. A. Taatjes, J. A. Miller, Proc. Combustion Inst. 32, 271 (2009)
d) Present calculation with B3LYP/CBS/cc-pV5Z level of calculation.
e) Present jet-cooled data.
f) See TG14.
a)
b)
 Conclusions:
 Jet-cooled CRD origin band spectra of HEP G1G2G3 conformer
and other three isotopologues are successfully obtained and
analyzed with evolutionary algorithm.
 Unusual lifetime broadening of spectra are measured and isotope
effect are strongly correlated to the intramolecular hydrogen
migration from the OH to the OO sites.
 Future works:
 Clarify the mechanism, with the assistance of higher level ab initio
calculation.
 A newly opened application of jet-cooled HRCRDS and EA to
characterize the hydrogen migration of radicals.
The Miller Group (OSU):
Dr. Miller
Dr. Meerts
Dmitry Melnik (MI13)
(EA and computer resource)
Phillip Thomas (MI04)
Jinjun Liu (TG14)
Rabi Chhantyal-Pun (MI07)
National Taiwan University:
Terrance Codd
Pei-Nung Chen
Neal Kline
(discussion of synthesis)
Funding: NSF
DOE
Your attention!
NO3 talk on Wednesday: WJ04