High resolution infrared spectrum and analysis of the 2v₃, 3v₃-v₃ and v₁-v₃ bands of CF₃ Br

Abstract

The vibro-rotational spectrum of CF₃Br in natural isotopic abundance has been recorded in the 14 μm region using a tunable diode laser spectrometer. The difference band v ₁-v ₃ (around 732 cm^-1), the overtone 2v ₃, as well as the hot-band 3v ₃-v ₃, (both around 700 cm^-1) of both isotopic species, CF₃ ⁷⁹Br and CF₃ ⁸¹Br, were analysed. The K-structure could be resolved for most of the bands observed. Accurate molecular constants for the v ₃, 2v ₃ and 3v ₃ levels were determined from a least squares fit of the observed transition frequencies. The validity of the additivity rule for α ^A and α ^B constants is discussed in general and in particular for all parallel bands of CF₃Br which involve the v ₃ vibration.