A. Barbe, M.-R. De Backer-Barilly, Vl.G. Tyuterev

Analysis of CW-CRDS spectra of Analysis of CW-CRDS spectra of 1616OO33 : :6000 to 6200 cm6000 to 6200 cm-1-1 spectral range spectral range

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)

Typical sensitivity 310-10 cm-1 Lambdameter

Photodiode

Optical isolator

Laser diode

Coupler

AO Modulator

laser ON Laser OFF

-50 0 50 100

threshold

=f(T,I)

6nm/diode40 diodes

Illustration of the achieved sensitivity: The example of the a1Δg (0)−X3g−(1) of O2

k=8×10-31cm/molec

Chem. Phys. Lett. 409 (2005) 281–287

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

6000 6020 6040 6060 6080 6100 6120 6140 6160 6180 6200

Wavenumber (cm-1)

Abs

orpt

ion

coef

ficie

nt (a

.u.)

2211+2+222+3+333 ## 11+2+222+4+43311+5+533 ##

2211+3+322+3+333--22

22+4+433

11++22

Global survey of the 6000 – 6200 cmGlobal survey of the 6000 – 6200 cm-1-1 spectral range spectral range

(034)

(510)(161)

(223)

(124)

6000

6100

6200

E/hc (cm-1)

(105)

Vibrational states and resonance schemeVibrational states and resonance scheme

VViibbrraattiioonnaall ddiiaaggoonnaall bblloocckk

222

xyJ

22

xy

2

zKJ

2

xy

4

zK

32

J

222

zJK

24

zKJ

6

zK

22

xyJ

2

xy

2

zK

22

J

22

zJK

4

zK

2

xy

22

z

VVVV

Jh2J,Jh

J,JhHJHJHJHJ2J,J

JJJCB21CB

21JCB

21AEH

J J

J J J J

J J J

where BAABB,A and 2

y

2

x

2

xyJJJ

RRoo--vviibbrraattiioonnaall eexxttrraaddiiaaggoonnaall bblloocckkss

...J2/1J2/1JJCJ2/1J2/1JJC

JJCJJCJ2/1J2/1JJCJ2/1J2/1JJCJJCH

zz

2

211

3

z

3

z031

33

003

2

201

2

z

2

z021

zz011001

'VV

Coriolis

J J

...JJFJFFFH 22

002

2

z020

2

200000

'VV

Anharm

J

where yxJ

i1JJ

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 Kccalculation of energy levels, transitions, and intensities : GIP program. (S. A. Taskhun)

Hamiltonian matrixHamiltonian matrix

The linestrenghths are calculated using the following effective transition

moment operators :

For A-Type band : odd vv 3'3

xyyx6zyyzxx5xyyx4

2zz3

2z2z1z

)'3v'

2v'1v)(3v2v1v( J,iiJ,

21dJ,Ji,iJ,J,

21dJ,iiJ,

21dJ,dJ,dd~

2xyz8zyyzxx7 J,dJ,Ji,iJ,J,d

For B-Type band : even vv 3'3

yxy

2xyx7zxz6yz5zy4

2zx3

2x2x1z

)'3v'

2v'1v)(3v2v1v( J,Ji,iJ,

21dJ,J,diJ,dJ,idJ,dJ,dd~

yxy2xyx8 J,Ji,iJ,

21d

Where BAABB,A and i'vv

i dd

Line intensitiesLine intensities

Parameter (034) (105)(105) (161) (510)(510) (223)(223) (124)(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)

105

g 0.1536 (84) g g 0.840 (11) 0.5593 (47)

106

g g g g 0.10458 (48) g

Coupling parametersCoupling parameters

(21) 0.00267A 1223,161

002

(15) 0.000033A 6124,510

200

(15) 0.0087A 5105,223

002

(57) 0.0856C 4124,223

001

(11) 0.0167C 7124,223

011

(35) 0.00747C 4105,034

001

(12) 0.124C 2223,034

001

(12) 0.0085C 6223,034

011

(10) 0.1026C 4105,510

001

(10) 0.03597C 8223,510

001

Spectroscopic parameters (cmSpectroscopic parameters (cm-1-1))

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

6.86.8

Range of upper state quantum numberRange of upper state quantum number

Operator Parameters ValueNumber of transitions

(J max, Ka max)

rms deviation

(%)

32 +43 band

d1 (×105) 0.514 (11) 101 (40, 3)

26.5

d2 (×108) -0.2942(76)

d5 (×106) -0.8027 (11)

1 + 53 band

d1 (×104) -0.31907(43) 248 (43, 10)

37.7

d3 (×107) -0.2003 (84)

d5 (×108) 0.980(46)

21 + 22 +33 band

d1 (×104) -0.8464 (12) 238 (42, 14)

29.2

d2 (×107) 0.1379(11)

1 + 22 +43 band

d1 (×104) 0.11849 (70) 134 (42, 6)

52.6

d2 (×108) -0.727 (11)

d5 (×105) -0.14783 (28)

Z

2Z J,

2ZZ J,

zyyzxx J,Ji,iJ,J,21

Z

X

2x J,

yz Ji,

X

2x J,

yz Ji,

Parameters of the transition moment operators (Debye)Parameters of the transition moment operators (Debye)

****

ObservedObserved

CalculatedCalculated

* * COCO22

303011

313122

232355

222266

262666

252577

212122

222211

232322

242411

292911

282800

252522

262611

191922

202011

Wavenumber (cmWavenumber (cm-1-1))

Abs

orpt

ion

Coe

ffici

ent (

a.u.

)A

bsor

ptio

n C

oeffi

cien

t (a.

u.)

Observed and calculated spectrum of the Observed and calculated spectrum of the 11 + 2 + 222 + 4 + 433 band band

in the 6156 – 6157 cmin the 6156 – 6157 cm-1-1 range range

Remarks : B - type band intensitiesRemarks : 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 21+23( 4141 cm-1)

and 21+2+23 (4783 cm-1).

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.

In general, FOR OZONE :

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 .

0.92

0.93

0.94

0.95

0.96

0.97

0.98

0.99

1

6006 6056 6106 6156 6206

Tran

smis

sion

(a.u

.)

Wavenumber (cm-1)

Only d1 for B-type band ( d5=0):

All di fitted parameters for B-type bandAll di parameters for A-type band = 0

All di fitted parameters for A and B type bands

Calculated spectra of the Calculated spectra of the 1 1 + 2+ 22 2 + 4+ 433 band in 3 cases band in 3 cases(normalisation on observed lines in the 6155 cm(normalisation on observed lines in the 6155 cm-1-1 region) region)

ConclusionConclusion

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.