New spectrum of the SiO+ molecule

Abstract

A new spectrum of SiO+ in the region 4300–4100 Å has been obtained by a r-f. discharge through a flowing mixture of argon and SiCl4 which contained a trace of oxygen. This spectrum is mainly a long sequence Δν = 0. The rotational structure of the three bands 0–0, 1–1, and 2–2 has been analyzed and the rotational constants of the upper and lower states are determined.The known spectrum of SiO+ in the region around 3840 Å (Woods 1943) has also been obtained, with improved intensity under the above conditions and has been reanalyzed. It is found that the earlier numbering of the lines of this system is wrong by one unit and that the lower state of these bands and the upper state of the new bands represent the same state. The weak band, which was analyzed by Woods as 1–1, appears to fit as 2–2 according to the new analysis.Rotational constants of the three 2Σ states, which are named X, A, and B, are shown below (in cm−1):[Formula: see text]A discussion on electron configurations has also been included.