The ultraviolet spectrum of AlO

Abstract

The E2Δi–A2Πi transition of AlO in the ultraviolet region has been excited in a high frequency discharge through a flowing mixture of AlCl3 vapour, argon, and oxygen and photographed at high resolution. The 0–0 and 0–1 bands of this transition at 2500.1 and 2545.9 Å respectively have been analysed for the rotational structure. Rotational perturbations and predissociation have been observed in the E2Δi state. Λ-doubling has been observed in both the bands for the transition E2Δ3/2–A2Π1/2. A weak rotational perturbation has been detected in the ν = 1 level of the A2Π3/2 state. In the same spectral region the 1–1, 2–2, 3–3 bands (observed for the first time) and the 1–2 band of the D2Σ+–X2Σ+ system have also been recorded and analysed for their rotational structure.