Emission spectroscopy of the B$^{2}{\mathsf \Sigma}^{+}\!\rightarrow \!{\mathsf X}^{2}{\mathsf \Sigma}^{+}$ system of ¹²C¹⁸O⁺ 

Abstract.

The emission spectrum of the B²Σ⁺→ X²Σ⁺ system of ¹²C¹⁸O⁺ has been investigated by using conventional spectroscopic techniques. The 0–1, 0–3, 1–2, 1–4 and 2–5 bands were recorded with high resolution (reciprocal linear dispersion was about 0.030–0.040 nm/mm) and spin splitting of the spectral lines has been precisely studied. Approximately 700 transition wavenumbers were measured with an estimated accuracy of 0.005 cm^-1. The rotational analysis has been performed and molecular constants, for the ground X²Σ⁺ and excited B²Σ⁺ states, have been extracted. In particular, more reliable values of the spin-rotation interaction constants for the $B^{2}\Sigma^{+}\ (v = 0, 1, 2)$ state were found to be: γ₀=2.0415(37)×10^-2 cm^-1, γ₁=1.9495(30)×10^-2 cm^-1 and γ₂=1.8554(59)×10^-2 cm^-1, respectively. Also new values of the principal equilibrium parameters and vibrational terms values for B²Σ⁺ and X²Σ⁺ states have been provided.