First analysis of the high resolution FTIR spectrum of the ν2 band of the FCO2 radical at 970.2 cm−1

• Published in: Molecular physics 2010-03, Vol.108 (6), p.723-731
• Main Authors: Perrin, A., Střižík, M., Beckers, H., Willner, H., Zelinger, Z., Pracna, P., Nevrlý, V., Grigorová, E.
• Format: Article
• Language: English
• Subjects: Fermi resonances; fluoroformyloxyl radical; high resolution IR spectrum; rotational analysis; spin-rotation interactions
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268970903514579

The infrared spectrum of the fluorocarboxyl radical, FCO 2 , was recorded at high resolution (0.0035 cm −1 ) in the 600-1400 cm −1 region on a Bruker IFS 120 HR Fourier transform spectrometer of the University of Wuppertal. The analysis of the A-type ν 2 band of FCO 2 (CF stretching mode) centred at 970.208 cm −1 was performed making use of the ground state parameters achieved by [L. Kolesniková, J. Varga, H. Beckers, M. Šimečková, Z. Zelinger, L. Nová Stříteská, P. Kania, H. Willner, and Š. Urban, J. Chem. Phys. 128, 224302/1 (2008)]. For the FCO 2 radical, the ν 2 transitions are, in principle, split into two spin-rotation subcomponents corresponding to J = N ±1/2. However the spin-rotation parameters in the 2 1 vibrational state have values similar to those of the ground state, and spin-rotation doublings are observable only for the weaker transitions involving medium K a or K c values in the P and R branches. The ν 2 fundamental band is weakly perturbed by the 2ν 5 dark overtone band at 965.4 cm −1 and the 2 1 and 5 2 energy levels of FCO 2 are coupled through Fermi type resonances. The final energy level calculation was performed accounting both for the spin-rotation interaction within the 2 1 and 5 2 vibrational states, and the 2 1 ⇔ 5 2 Fermi-type resonances.