Infrared-Emission Spectrum of HBr Excited in an Electric Discharge. Determination of Molecular Constants

Abstract

The infrared‐emission spectra of H⁷⁹Br and H⁸¹Br have been observed by exciting HBr in an electric discharge. Lines in the 1–0, 2–1, and 3–2 bands have been measured to an accuracy of the order of 0.01 cm⁻¹. Pure rotational transitions of H⁷⁹Br and H⁸¹Br which were not resolved have also been observed and measured with an accuracy of the order of 0.2 cm⁻¹. Values are reported for ω_e, ω_ex_e, ω_ey_e (only limits for this constant), B_e, D_e, α_e, β_e, γ_e, δ_e, and approximate values of H₀ and H₁ are also obtained. The results are found to be in agreement with Dunham's theory. Values of the potential constants a₁, a₂, and a₃ are calculated. The B_e values for H⁷⁹Br and H⁸¹Br agree with calculations based on microwave measurements of D⁷⁹Br and D⁸¹Br.