HIGH RESOLUTION SPECTROSCOPY OF THE TWO LOWEST VIBRATIONAL STATES OF QUINOLINE C9H7N

O. PIRALI, Z. KISIEL, M. GOUBET, S. GRUET, M.-A. MARTIN-DRUMEL, A. CUISSET, F. HINDLE, G. MOURET

Institut des Sciences Moléculaires d’Orsay, CNRS-Université Paris-Sud

AILES beamline, synchrotron SOLEIL

Institute of Physics, Polish Academy of Sciences, Warszawa, Poland;

Laboratoire PhLAM, Université de Lille 1, Villeneuve de Ascq, France

Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, Dunkerque, France.

Low energy vibrational states of quinoline

GS A’

44 A’’ (178 cm-1)

45 A’’ (168 cm-1)

Prolate asymmetric topµa=0.2 D and µb=2.1 D45 vibrational modes (31 A’ and 14 A’’)

GS constants from Kisiel et al., JMS, 217 (2003)

0

170

cm-1

245 (338 cm-1)

244 (355 cm-1)45 + 44 (347 cm-1) 43 (392 cm-1)

43 (378 cm-1)350

FT-FIR spectroscopy (SOLEIL) : 45 – GS band

P branch R branch

- Spectral resolution = 30 MHz

- Determination of E45

- Rough values of A, B, C ES constants

- E45 - E44 separation

Sub-mm spectroscopy (LPCA+Warsaw):

- 140-220 GHz spectral range- 30 kHz line accuracy- b-type pure rotation in the GS, 45, 44

- Interstates transitions

- GS transitions- 45 transitions- 44 transitions

FTMW spectroscopy (PhLAM): ES transitions in the jet

45

44

Spherical moving mirror

MW Radiation

Gas injection

L-shaped antenna Vacuum : ≈ 10-6 mbar

Step by step motor

Stainless steel cell

Spherical mirror(Aluminum)

Pumping group

Pulsed nozzle

Gaussian beam profileW0= 42 mm à 12 GHz

1200 mm

Supersonic Jet

About 55 b-type transitions within 45 and 44

ES transitions are 1000 less intense than the corresponding GS transitions

25 GS a-type transitions

Frequency accuracy better than 2 kHz

Spectral analysis and identification of several perturbations

Use of AABS, LWW, and SPFIT/SPCAT softwares to analyse all the data

- 2 clear series of interacting levels with Ka=2- Other pertubed levels with unidentified perturbing partner

45 44

𝐻𝑟𝑜𝑡 =[𝐴− 12 (𝐵+𝐶 )] �̂� 𝑧2+(𝐵+𝐶 ) �̂� 2+ 1

2(𝐵−𝐶 ) ( �̂�𝑥2− �̂� 𝑦

2 )

− 𝐽 �̂�4− 𝐽𝐾 �̂�

2 �̂� 𝑧2−𝐾 �̂� 𝑧

4−𝐾 [ �̂� 𝑧2 , �̂� 𝑥2− �̂� 𝑦2 ]+¿−2 𝐽 �̂�

2 ( �̂� 𝑥2− �̂� 𝑦2 )¿

( 𝐻𝑟𝑜𝑡 𝐻𝑐𝑜𝑟

(45,44)+𝐻 𝐹(45,44 )

𝐻 𝑐𝑜𝑟(45,44 )+𝐻 𝐹

(45,44) 𝐻𝑟𝑜𝑡 +𝐸(45−44))

𝐻𝑐𝑜𝑟(45,44)=𝑖 (𝐺𝑐+𝐺𝑐

𝐽 𝑃2+𝐺𝑐𝐾 𝑃𝑧

2+… )𝑃 𝑦+(𝐹 𝑎𝑏+…)(𝑃𝑧𝑃 𝑥+𝑃𝑥𝑃 𝑧)

H F(45,44)=W F+W F

J P2+W FK P z

2+¿+[ (𝑊 ±+𝑊 ±

𝐽𝑃2+𝑊 ±𝐾 𝑃 𝑍

2 ) ,𝑃 𝑥𝑦2 ]+¿+… ¿

Hamiltonian : Watson A reduction and Ir representation

45

E45 5049310.(47)A 3141.723(10)B 1271.9959(11)C 906.4587(11)J 0.0191541(71)JK 0.056545(79)K 0.08473(12)J 0.00596471(64)K 0.0593138(77)

44

E44-E45 277935.(94)A 3142.092(10)B 1271.6425(11)C 906.4012(11)J 0.0192330(70)JK 0.037301(79)K 0.23231(12)J 0.00535848(62)K 0.0609730(72)

Results of the fit for 45 and 44

45/44

Gc 107.701(37)GcJ ‐0.0003270(16)GcK ‐0.001388(13)Fab [ 0.]Wf 22652.(288)WfJ ‐0.5218(19)WfK 5.5069(26)W [ 0.]WJ [ 0.]WK ‐0.000003605(29)

GS

A 3145.533086(71)B 1271.578056(61)C 905.739457(38)J 0.0191129(28)JK 0.0470270(89)K 0.161469(18)J 0.0056627(13)K 0.060613(22)

Lines RMS RMS error J’’ range Ka’’ range

GS 258 0.028 MHz 0.95 1-143 0-5845 3012 0.048 MHz 0.81 2-148 0-5844 2999 0.048 MHz 0.81 1-130 0-58

45 - GS 3578 0.0002 cm-1 1.02 9-114 9-60

E45 – EGS 5047475.91(13)E44 – E45 281603.51(13)

A 3141.723(10)B 1271.9959(11)C 906.4587(11)

Intercorrelation between parameters

ES rotational parameters

A 3142.092(10)B 1271.6425(11)C 906.4012(11)

Fermi parameter and vibrational energies

45

44

(𝐸 45 𝑊 𝐹𝑊 𝐹 𝐸 44−𝐸45)

(A1+A2)/2 3141.907426(29)(B1+B2)/2 1271.819307(15)(C1+C2)/2 906.429956(13)

(A1-A2)/2 ‐0.188(10)(B1-B2)/2 0.1771(10)(C1-C2)/2 0.0292(11)

45 5049310.(47)44 – 45 277935.(94)WF 22652.(288)

Conclusions

Use of very complementary techniques to study the rotational structure of GS, 45, and 44

Observation of perturbations in the rotational levels of 45 and 44

Similar difficulties might be encountered in the IR spectra of many PAHs molecules

Seems difficult to detect in the c-type transitions recorded by FTIR techniques

Analysis of the pure rotation transitions observed within the next vibrational polyad seems rather difficult

Acknowledgments

Beamtime allocation 20131274

ANR grant “GASPARIM”