High-resolution infrared spectroscopy of CH₂⁸¹BrF near 8 μm: rovibrational analysis of the ν₃ and ν₈ fundamentals and resonances with the dark states 2ν₅ and ν₆ + ν₉

Abstract

Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tmph20High-resolution infrared spectroscopy of CH 2 81 BrF near 8 µm: rovibrational analysis of the ν 3 and ν 8 fundamentals and resonances with the dark states 2ν 5 and ν 6 + ν 9 resolution infrared spectroscopy of CH 2 81 BrF near 8 µm: rovibrational analysis of the ν 3 and ν 8 fundamentals and resonances with the dark states 2ν 5 and ν 6 + ν 9 , High-resolution infrared spectroscopy of CH 2 81 BrF near 8 μm: rovibrational analysis of the ν 3 and ν 8 fundamentals and resonances with the dark states 2ν 5 and ν 6 + ν 9The infrared spectrum of isotopically enriched CH 2 81 BrF was investigated in the ν 3 and ν 8 region between 1150 and 1370 cm −1 at a resolution of 0.003 cm −1 . The ν 3 vibration of symmetry species A gives rise to an a-/b-hybrid band with a-type predominance, while the ν 8 mode of A symmetry produces c-type absorption. Due to the proximity of the band origins to those of closely lying overtones and combination bands, the v 3 = 1 and v 8 = 1 levels were found perturbed through Coriolis resonance by the v 5 = 2 (A ) and v 6 = v 9 = 1 (A ) states, respectively. The spectral analysis resulted in the identification of 3132 transitions (J ≤ 98 and K a ≤ 14) for the ν 3 and 2958 transitions (J ≤ 68 and K a ≤ 19) for the ν 8 bands. The assigned data were fitted using the Watson's A-reduction Hamiltonian in the I r representation and the perturbation operators. Although no transitions belonging to the perturbers were observed, the band origins and excited state parameters for fundamentals and 'dark states' together with coupling terms for the ν 3 /2ν 5 and ν 8 /ν 6 + ν 9 dyads were determined.