Transcript DeBacker_columbus.ppt

Analysis of CW-CRDS spectra of 16O3 :
6000 to 6200 cm-1 spectral range
A. Barbe, M.-R. De Backer-Barilly, Vl.G. Tyuterev
Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 6089,
Université de Reims, FRANCE
A. Campargue, S. Kassi, D. Romanini
Laboratoire de Spectrométrie Physique, UMR CNRS 5588,
Université Joseph Fourier, Grenoble, FRANCE
The compact fibered CW-CRDS spectrometer (Grenoble)
1480-1687 nm (5800-7000 cm-1)
6nm/diode
40 diodes
Typical sensitivity 310-10 cm-1
Laser diode
Lambdameter
n=f(T,I)
Optical isolator
threshold
Laser OFF
laser ON
-50
0
Photodiode
50
100
Coupler
AO
Modulator
Absorption coefficient (10
-10
-1
cm )
Illustration of the achieved sensitivity:
The example of the a1Δg (0)−X3Sg−(1) of O2
6325.4
6325.6
6.0
6325.8
6326.0
HDO
k=8×10-31cm/molec
4.0
Q
Q
Q
Q(13)
Q(11)
Q
Q(9)
Q(7)
H 2O
2.0
Q
Q(5)
Q
Q(3)
0.0
0.5
(obs.-calc.)
0.0
-0.5
6325.4
6325.6
6325.8
6326.0
-1
W avenumber (cm )
Chem. Phys. Lett. 409 (2005) 281–287
Global survey of the 6000 – 6200 cm-1 spectral range
0.18
0.16
Absorption coefficient (a.u.)
0.14
0.12
5n1+n2
0.1
0.08
3n2+4n3
0.06
0.04
0.02
0
6000
6020
6040
6060
6080
6100
6120
6140
6160
Wavenumber (cm-1)
2n1+3n2+3n3-n2
n1+5n3 #
2n1+2n2+3n3 #
n1+2n2+4n3
6180
6200
Vibrational states and resonance scheme
E/hc (cm-1)
6200
(124)
(223)
6100
(510)
(161)
(105)
(034)
6000
Hamiltonian matrix
Vibrational diagonal block
1
1
1


H  E   A   B  C  J   B  C  J  B  C J   J   J J    J 
2
2
2


  J , J   2 J J  H J  H J J  H J  J   H  J   h J , J 
VV
VV
2
2
2
z
K
2
2
z
xy
 h J , J
KJ
where
2
2
z
xy
2
J
J
2
6
xy
K
 2h J
2
J
2
xy
A, B  AB  BA
4
xy
4
z
KJ
2
2
z
JK
2
K
2
z
JK
2
2
z
2
2
z
2
J
3
J
K
4
2
z
xy
J 
2
2
J J J
and
2
2
2
xy
x
y
Ro-vibrational extradiagonal blocks
H
VV '
Coriolis
 J  J   C  J  J  1 / 2    J  1 / 2 J 
 C J  J  1 / 2    J  1 / 2  J   C J  J  J   C J  J 
 C J  J  1 / 2    J  1 / 2  J   C J  J  J  1 / 2    J  1 / 2 J   ...
C
001



011
z

021
2
z

H
VV '
Anharm

201

211
3
z
3
2
z
3
031

z
2


003
3


2
z

z
z

 F  F J  F J  F  J  J   ...
2
000
020
1
i
where J  J  J

2
200
x
z
002
2
2


y
Assignments :
vibration : predictions from Vl. G. Tyuterev – keep the usual label v1 v2 v3.
rotation : use of ASSIGN program (Chichery A.) based on Ground State Combination
Differencies (GSCD) - J Ka Kc
calculation of energy levels, transitions, and intensities : GIP program. (S. A. Taskhun)
Line intensities
The linestrenghths are calculated using the following effective transition
moment operators :
'
For A-Type band : v 3  v 3 odd
( v1v 2 v 3 )( v1' v '2 v '3 ) ~

   12  , iJ  i , J  d 12  ,J
 d 7  x , J x , J z  i y , iJ y , J z  d 8  z , J 2xy 
z  d1z  d 2 z , J 2  d 3 z , J 2z  d 4
x
y
y
x
5
x
x , Jz
 i y , iJ y , J z  d 6 1 x , iJ y  i y , J x 
2
'
For B-Type band : v 3  v 3 even

 


 z  d1 x  d 2  x , J 2  d 3  x , J 2z  d 4 i y , J z  d 5  z , iJ y  d 6  z , J x , J z  d 7
( v1v 2 v 3 )( v1' v '2 v '3 ) ~
 d8


1
 x , J 2xy  i y , iJ x , J y
2
Where A, B  AB  BA and
d i  vv' d i



1
 x , J 2xy  i y , iJ x , J y 
2
Spectroscopic parameters (cm-1)
Parameter
(034)
(105)
(161)
(510)
(223)
(124)
EVV
6046.06955 (39)
6063.92240 (14)
6087.497 (96)
6100.2169 (11)
6124.28684 (17)
6154.70228 (17)
A-(B+C)/2
3.173610 (38)
2.9865840 (96)
3.36939(65)
3.183553 (59)
3.080385 (13)
3.123868 (15)
(B+C)/2
0.3975017 (77)
0.3977916(12)
0.395109 (39)
0.4115987 (15)
0.3933159 (95)
0.3946318 (59)
(B-C)/2
0.0263676 (74)
0.0256424(13)
0.022679 (60)
0.0189955 (75)
0.0264627 (97)
0.0271057 (72)
K
103
g
0.19154 (19)
g
g
0.28243 (14)
0.26212 (29)
JK
105
g
-0.5049 (13)
g
g
0.0451 (16)
-0.5498 (16)
J
106
g
0.42184 (75)
g
g
0.6633 (13)
0.32578 (37)
J
106
g
0.10435 (40)
g
0.1339 (43)
0.04617 (81)
0.11907 (26)
K
105
g
0.1536 (84)
g
g
0.840 (11)
0.5593 (47)
HK
106
g
g
g
g
0.10458 (48)
g
Coupling parameters
, 223
A161
 0.002671 (21)
002
,105
C034
 0.007474 (35)
001
,124
A510
 0.0000336 (15)
200
, 223
C034
 0.1242 (12)
001
223,105
A002
 0.00875 (15)
, 223
C034
 0.00856 (12)
011
223,124
C001
 0.08564 (57)
,105
C510
 0.10264 (10)
001
223,124
C011
 0.01677 (11)
, 223
C510
 0.035978 (10)
001
Range of upper state quantum number
state of the
work
Vibrational
Assignment
Band center
(cm-1)
Number of
transitions
J max
Ka max
rms (×103)
cm-1
completed
(233)  (010)
6015.605
322
37
11
3.7
In progress
(034)  (000)*
6046.970
151
40
4
32.1
completed
(105)  (000)
6063.933
531
43
10
3.3
completed
(510)  (000) *
6100.216
22
29
4
10.2
completed
(223)  (000)
6124.286
507
44
14
5.4
completed
(124)  (000)*
6154.702
479
49
7
5.9
6.8
Parameters of the transition moment operators (Debye)
Operator
Parameters
Value
Number of
transitions
(J max, Ka max)
rms
deviation
(%)
101
(40, 3)
26.5
248
(43, 10)
37.7
238
(42, 14)
29.2
134
(42, 6)
52.6
3n2 +4n3 band
X
x , J 
z ,iJ y 
2
0.514 (11)
d2 (×108)
-0.2942(76)
d5 (×106)
-0.8027 (11)
n1 + 5n3 band
Z
 Z ,J
d1 (×105)
2
Z

1
x , J x , J z  iy , iJ y , J z 
2
d1 (×104)
-0.31907(43)
d3 (×107)
-0.2003 (84)
d5 (×108)
0.980(46)
2n1 + 2n2 +3n3 band
Z
 Z , J
2

d1 (×104)
-0.8464 (12)
d2 (×107)
0.1379(11)
n1 + 2n2 +4n3 band
X
d1 (×104)
0.11849 (70)
x , J 2 
d2 (×108)
-0.727 (11)
d5 (×105)
-0.14783 (28)
z ,iJ y 
Observed and calculated spectrum of the n1 + 2n2 + 4n3 band
in the 6156 – 6157 cm-1 range
Observed Absorption Coefficient (a.u.)
Absorption Coefficient (a.u.)
Calculated Absorption Coefficent (a.u.)
0.025
Calculated
26 280
0.020 1
252 291
0.015
201
257 226
0.010
192
0.005
0.000
6156.1
312
241 221
301
232 212
266 235
6156.2
6156.3
6156.4
6156.5
6156.6
6156.7
6156.8
6156.9
6157
-1
Wavenumber (cm )
0.025
Observed
0.020
*
CO2
0.015
0.010
0.005
0.000
6156.1
*
*
6156.2
6156.3
6156.4
6156.5
6156.6
6156.7
Wavenunber (cm-1)
Wavenumber (cm-1)
6156.8
6156.9
6157
Remarks : B - type band intensities
Observing and assigning B type bands (ΔKa= ± 1) at this high energy level range (>6000 cm-1)
represent a challenge
Remember : with the Reims F.T.S, the highest observed B-type bands were 2n1+2n3( 4141 cm-1)
and 2n1+n2+2n3 (4783 cm-1).
In general, FOR OZONE :
 A-type bands are strong and their feature presents a compressed R branch.
 B-type bands are much weaker than A-type bands at a given energy level range and they
extend over a much larger spectral range.
B-type bands are never totally observed , being overlapped by stronger A-type
bands, and often partly hidden by impurities, like H2O,CO2,CO…
Finally, the general shapes of the B-type bands are difficult to reproduce in a first attempt :
 6 types of transitions may be observed
 Necessity to introduce unknown additional transition moment parameters d5 in order
to reproduce the line intensity observations and to “reduce” the Q branches which
are not visible in the spectra .
Calculated spectra of the n1 + 2n2 + 4n3 band in 3 cases
(normalisation on observed lines in the 6155 cm-1 region)
1
0.99
All di fitted parameters for A and B type bands
Transmission (a.u.)
0.98
0.97
0.96
All di fitted parameters for B-type band
All di parameters for A-type band = 0
0.95
Only d1 for B-type band ( d5=0):
0.94
0.93
0.92
6006
6056
6106
Wavenumber (cm-1)
6156
6206
Conclusion
For the first time, the high sensitivity of the CW-CRDS experimental set-up allowed to observe
many weak rovibrational transitions of ozone in the 6000-7000 cm-1 spectral range.
All the “relatively strong or medium intensity” lines are rotationally undoubtedly assigned.
This work confirms that the usual scheme of polyads for ozone (same value of v2 and Coriolis
and Darling-Dennison resonances) becomes less and less valid.
Necessity to introduce large vibrational couplings between many vibrational states in a
given neighborhood, even with large value of v2
Predictions of the interactions strengths between various partners become a real
challenge, as the number of possible interacting states becomes obviously larger and
larger as far as the energy is increasing
Using effective Hamiltonians and effective transition moment operators, we can correctly
reproduce the observed spectra for A and B-type bands.
We continue to study theoretically and experimentally the ozone spectra in these high
energy ranges in order to have a good final understanding of the dipole and of the potential
functions.