Millimeter Wave Spectroscopy of Unstable Molecular Species. I. Carbon Monosulfide

The carbon monosulfide species CS³² and CS³⁴ are investigated with a millimeter wave spectrometer designed for the study of short‐lived molecules in the frequency range from 60 000 to 300 000 Mc/sec. Spectroscopic constants obtained are: $$\begin{array}{cc}\mathrm{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}{\mathrm{CS}}^{32}& \mathrm{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}{\mathrm{CS}}^{34}\\ B_0\text{=24 495.592±0.006\hspace{0.17em}}\mathrm{Mc}/\sec & B_0\text{=24 103.554±0.006\hspace{0.17em}}\mathrm{Mc}/\sec \\ B_e\text{=24 584.367±0.006\hspace{0.17em}}\mathrm{Mc}/\sec & D_e\text{=0.03979±0.0017\hspace{0.17em}}\mathrm{Mc}/\sec \\ {\alpha }_e\text{=117.550±0.012\hspace{0.17em}}\mathrm{Mc}/\sec & H_e\text{=0.0625±0.009\hspace{0.17em}}\mathrm{kc}/\sec \\ D_e\text{=0.04285±0.00166\hspace{0.17em}}\mathrm{Mc}/\sec & \\ H_e\text{=0.0653±0.0085\hspace{0.17em}}\mathrm{kc}/\sec & \end{array}$$ The spectrometer is described. Its sensitivity has been estimated to be the order of 10^—5 to 10^—6 cm^—1.