High-resolution analysis of the 12.6 µm spectral region of the nitryl chloride ClNO2 molecule. (February 2019)

• Record Type: Journal Article
• Authors: Flaud, J.-M.; Anantharajah, A.; Tchana, F. Kwabia; Manceron, L.; Orphal, J.; Wagner, G.; Birk, M.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 224(2019)
• Page Start: 217
• Page End: 221
• Publication Date: 2019-02
• Subjects: Nitryl chloride -- ClNO2 -- High-resolution fourier transform spectroscopy -- Coriolis and Fermi resonances -- Line positions; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2018.11.020
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlight: Nitryl chloride ClNO2 . High-resolution Fourier transform spectroscopy. First analysis of the ν2, 2ν3 and 2ν6 bands taking into account the relevant Coriolis and Fermi resonances. Abstract: The 12.6 µm region of nitryl chloride (ClNO2 ) has been recorded at high resolution (0.00102 cm −1 ) using a Fourier transform spectrometer and the SOLEIL synchrotron light source. ClNO2 was found during our studies of chlorine nitrate and, after fractional distillations it was introduced into a multipass White cell made of inert materials, with an optical path length of 5.4 m. 320 scans were recorded for the range 600–980 cm −1 at a total pressure of 0.23 hPa and a temperature of 250 K. A thorough analysis of the ν2, 2ν6 and 2ν3 bands of 35 ClNO2 and of the ν2 band of 37 ClNO2 falling in this region has been carried out using a Hamiltonian model which takes explicitly into account the numerous resonances affecting the ro-vibrational energy levels; especially the C-type Coriolis resonance between the ν2 and the ν3 + ν6 modes. These two modes are only separated by less than 20 cm −1 and are thoroughly mixed. From the fittings, the following band centers were derived: νo (ν2 ) = 792.761264(60) cm −1, νo (ν3 + ν6 ) = 775.8923(20) cm −1, νo (2ν3 ) = 734.183576(20) cm −1 and νo (2ν6 ) = 819.836727(90) cm −1 for 35 ClNO2 and νo (ν2 ) = 792.258284(30) cm −1 and νo (ν3 + ν6 ) = 774.6826(30) cm −1 for 37 ClNO2 where the uncertainties are one standard deviation. Due to their sharp Q branches falling into an atmospheric "window", the detection of the ν2 bands might be an advantageous route for future attempts to quantify atmospheric ClNO2, using infrared techniques. Graphical abstract: Image, graphical abstract