HIGH-RESOLUTION SPECTROSCOPY AND PRELIMINARY GLOBAL ANALYSIS OF C--H STRETCHING VIBRATIONS OF C$_2$H$_4$ IN THE 3000 AND 6000 CM$^{-1}$ REGIONS

Abstract

Author Institution: Department of Chemistry, Universidad de Oriente, Cumana 6101, Estado Sucre, Venezuela; Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS-Universite de Bourgogne, 9. Av. A. Savary, BP 47870, F-21078 Dijon Cedex, France; Groupe de Spectrometrie Moleculaire et Atmospherique, CNRS UMR 6089, Moulin de la Housse, BP 1039, Cases 16-17, F-51687 Reims Cedex 2, France; Laboratoire de Chimie quantique et Photophysique, CP160/09, Faculte des Sciences, Universite Libre de Bruxelles, 50 ave. Roosevelt, B-1050, Brussels, Belgium; V.E. Zuev Institute of Atmospheric Optics SB RAS,1, Zuev Square, Tomsk, 634921, RussiaEthylene is a naturally occurring compound in ambient air that affects atmospheric chemistry and global climate. The C$_2$H$_4$ spectrum is available in databases only for the 1000 and 3000 cm$^{-1}$ ranges. In this work, {\em J. Quant. Spectrosc. Radiat. Transfer\/}, {\bf 111}, 2265--2278 (2010).}, the ethylene absorption spectrum was measured in the 6030-6250 cm$^{-1}$ range with the use of a high resolution Bruker IFS 125HR Fourier-spectrometer and a two-channel opto-acoustic spectrometer with a diode laser. As a secondary standard of wavelengths, the methane absorption spectrum was used in both cases. A preliminary analysis was realized thanks to the tensorial formalism developed by the Dijon group that is implemented in the XTDS software package, {\bf 251}, 102--113 (2008).}. We considered the two combination bands $\nu_5+\nu_9$ and $\nu_5+\nu_{11}$ as an interacting dyad. Parameters for the $\nu_9/\nu_{11}$ dyad were fitted simultaneously from a re-analysis of previously recorded supersonic expansion jet FTIR data, while parameters for the $v_5=1$ Raman level were taken from literature. More than 600 lines could be assigned in the 6030-6250 cm$^{-1}$ region (and also 682 in the 2950--3150 cm$^{-1}$ region) and effective Hamiltonian parameters were fitted, including Coriolis interaction parameters. The dyad features are globally quite well reproduced, even if there are still problems at high $J$ values