Knowledge Bank

“The pure rotational spectrum and the vibrational spectrum of $CS2$ vapour have been photographed with a 21 ft grating. Rotational lines up to $J=94$ have been measured and values of the constants $Bo$ and $Do$ have been determined. As is well known, the vibrational Raman spectrum of $CS2$, similar to that of $CO2$, consists of the Fermi diad $v1,2v2$ with some additional ``hot bands. In $CS2$, the resonance is not as strong as in $CO2$ and the $v1$ Q branch is by far the most intense line observed. In the present research, a total of 14 sharp Q branches were photographed in the region of the diad ($630-820cm-1$). Also the rotational structure of the $v1$ vibrational band was observed and analyzed. These results, together with published data on the infrared spectrum, are used to determine $Be$ and the vibrational constants $\omega i$ and $x1k$.”““