1. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 HIGH RESOLUTION SPECTROSCOPY AND PRELIMINARY ANALYSIS OF C–H STRETCHING VIBRATIONS OF C 2 H 4 IN THE 3000 AND 6000 cm -1 REGIONS M. A. LOROÑO GONZALEZ, Department of Chemistry, Universidad de Oriente, Cumaná 6101, Estado Sucre, Venezuela; V. BOUDON, M. LOËTE, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS-Université de Bourgogne, 9. Av. A. Savary, BP 47870, F-21078 Dijon Cedex, France; M. ROTGER, M.-T. BOURGEOIS, Groupe de Spectrométrie Moléculaire et Atmosphérique, CNRS UMR 6089, Moulin de la Housse, BP 1039, Cases 16-17, F-51687 Reims Cedex 2, France; K. DIDRICHE, M. HERMAN, Laboratoire de Chimie Quantique et Photophysique, CP160/09, Faculté des Sciences, Université Libre de Bruxelles, 50 ave. Roosevelt, B-1050, Brussels, Belgium; V. A. KAPITANOV, Yu. N. PONOMAREV, A. A. SOLODOV, A. M. SOLODOV, T. M. PETROVA, V.E. Zuev Institute of Atmospheric Optics SB RAS,1, Zuev Square, Tomsk, 634921, Russia.

2. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Contents I.The ethylene molecule II.Experimental details III.Global fit results IV.Conclusions and perspectives

3. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 I. The ethylene molecule

4. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Symmetry considerations  A B C  x y z  z y x  z x y Herzberg (III r representation) IUPAC (I l representation) I r representation We use only the I r representation The 12 normal mode vibrations are labeled accordingly We use a symmetrized tensorial formalism in O(3) ⊃  D 2h

5. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Normal modes (I r ) From M. Sanzharov, M. Rotger, Ch. Wenger, M. Loëte, V. Boudon, A. Rouzée J. Quant. Spectrosc. Radiat. Transfer, 112, 41–52 (2011)

6. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Tensorial formalism Systematic expansion of effective Hamiltonian and transition moment up to any order and for any polyad scheme, thanks to group theory and tensorial methods  All interactions are automatically included  Vibrational extrapolation  Global analyses ParametersRotationVibration

7. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Effective Hamiltonian and interactions V operators for the polyad j Exemple for n j = 3: {v 3 },  3 {v 2 },  2 {v 1 },  1 Hamiltonian for polyad j: Energy Ground state {0}, A g Polyad i with n i levels {v ni },  ni Polyad j with n j levels {v nj },  nj

8. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Effective Hamiltonian for C 2 H 4 Effective Hamiltonian for the v 5 = 1 level (= polyad P 1 ) Effective Hamiltonian for the Ground State (polyad P 0 ) Effective Hamiltonian for v 9 = 1 / v 11 = 1 (= polyad P 2 ) Effective Hamiltonian for v 5 = 1 / v 9 = 1 / v 11 = 1 (= polyad P 3 )

9. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 II. Experimental details

10. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Data sets From Brussels (ULB) in the 3000 cm -1 region: Supersonic expansion jet FTIR spectrum at 36 K rotational temperature. Resolution 0.01 cm -1 (Bruker IFS 120 HR) From Tomsk (IAO) in the 6000 cm -1 region: FTIR spectrum with 19 torr of ethylene in a 20 cm cell at room temperature. Resolution 0.005 cm -1 (Bruker IFS 125 HR) Photo-acoustic diode laser spectrum at room temperature using a hmome made two channel OA spectrometer

11. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Tomsk two-channel OA spectrometer Methanespectrum Laserpower Interferogram FSR = 0.05 cm -1 OAD signals/laser power Ethylenespectrum Diode lasers: Interval: 6030–6250 cm -1 Scan: 2.5–3 cm -1 Resolution: 0.00033 cm -1 Kapitanov V.A., Ponomarev Yu.N., Tyryshkin I.S and Rostov A.P.: Spectrochimica Acta Part A, 66A, 4-5, 811-818 (2007)

12. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 III. Global fit results

13. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Fit details GS, ν 5, ν 9 and ν 11 where first taken form the literature and converted to the tensorial form This allowed a first simulation and assignment of the 3000 cm - 1 region; 40 parameters were fitted In the same way, we assigned and fitted the 6000 cm -1 region; 20 parameters were fitted In both polyads, Coriolis interaction parameters were fitted

14. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Overview of the 3000 cm -1 region

15. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Residuals in the 3000 cm -1 region

16. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Overview of the 6000 cm -1 region

17. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 The R branch of ν 5 + ν 9

18. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Detail of ν 5 + ν 11

19. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Residuals in the 6000 cm -1 region

20. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 Rovibrational energy levels

21. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 IV. Conclusion and perspectives

22. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 What next ? High resolution stimulated Raman spectra of ν 5 (D. Bermejo, Madrid), analysis in progress New FTIR spectra of the 3000 cm -1 region (J. Vander Auwera, Brussels) with intensity measurements, analysis in progress New FTIR spectra of the 1000 cm -1 region (J. Vander Auwera, Brussels) with intensity measurements, analysis of ν 4 /ν 7 /ν 10 /ν 12 as a tetrad in progress Set up of a server of calculated lines of ethylene, within the VAMDC European network

23. 66th Ohio State University Symposium on Molecular Spectroscopy June 20–24, 2011 The D 2h TDS package D 2h Top Data System www.icb.cnrs.fr/OMR/SMA/SHTDS Molecular parameter database Calculation and analysis programs XTDS : Java interface