15min:

V. SIRONNEAU, P. CHELIN, F. KWABIA TCHANA, I. KLEINER, Laboratoire Interuniversitaire des Systèmes Atmosphériques, CNRS et Universités Paris 7 et Paris 12, 61 av. Général de Gaulle, 94010, Créteil, France; J. ORPHAL, Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany; O. PIRALI, Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, 91192 Gif-sur-Yvette, France; J-C. GUILLEMIN, Sciences Chimiques de Rennes -Ecole Nationale Supérieure de Chimie de Rennes -CNRS -35700 Rennes, France; L. MARGULES, R. MOTIYENKO, Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Universitée de Lille I, F-59655 Villeneuve d’Ascq Cédex, France; S. COOKE, W. J. YOUNGBLOOD, A. AGNEW, C. T. DEWBERRY, Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203, U.S.A.

Methyl nitrite CH₃ONO is an important species in atmospheric chemistry involved in photochemical oxidation of volatile organic compounds. The cis conformer (more stable by about 298 cm^-1) has a high internal rotation potential barrier for the methyl group (731 cm^-1) whereas for the trans conformer the barrier to internal rotation is extremely low (10 cm^-1), leading to large internal rotation splittings. Only one high resolution infrared study was performed prior to this study. For the first time, high-resolution spectrum of CH₃ONO was recorded in the far infrared region (30-500 cm^-1) using the synchrotron SOLEIL far-infrared beamline (AILES) and a Fourier transform (FT) spectrometer. Some 987 lines were assigned for the cis isomer up to J=65 and combined with 66 previously recorded microwave lines. In addition, high-resolution spectrum of the ₉ band of the cis isomer around 627.9 cm^-1 was also recorded using the FT spectrometer at LISA. New microwave data is currently recorded to improve the knowledge of both the cis and trans ground state parameters.