Fourier transform emission spectroscopy at 13 μm: Vibration–rotation spectrum of SiS

The vibration–rotation emission spectrum of the high temperature molecule SiS was recorded with a Fourier transform spectrometer. The observation of a high resolution emission spectrum at 13 μ (750 cm−1) is unusual but we believe this technique is generally applicable to high temperature species. Seven bands (1–0 through 7–6) of the main isotopic form, 28Si32S, were observed along with three bands (1–0, 2–1, and 3–2) for each of the minor species, 29Si32S, 30Si32S, and 28Si34S. Mass-reduced Dunham parameters, including Watson’s correction due to the breakdown of the Born–Oppenheimer approximation, were derived from the data.