Infrared Spectrum of σ2 for B10F3 and B11F3

Abstract

The infrared grating spectra of σ₂ for B¹⁰F₃ and B¹¹F₃ have been reexamined from 650 to 750 K. Two samples of BF₃, one composed of 93.4 percent B¹⁰F₃ and 6.6 percent of B¹¹F₃, and the other of the normal abundance ratio 20 percent B¹⁰F₃ and 80 percent B¹¹F₃ were secured for the investigation. Complete resolution of the rotational fine structure of this parallel‐type band was achieved. The following constants were obtained by means of the usual sort of rotational analysis: for B¹⁰F₃, σ₀ = 718.23 K, B₀ = 0.3527₂ K, B(v₂ = 1) = 0.3528₈ K, D_J = 13.72×10^—7 K. For B¹¹F₃, σ₀ = 691.45 K and the rotational constants are the same for the two isotopic species.