Far-Infrared Torsional Vibration Spectra of One-, Two-, and Three-(CX3) Top Molecules

The far-infrared torsional vibration spectra in the 350–40-cm−1 spectral region are reported for the gaseous state of the following compounds: Ethyl chloride, propylene, deuterated ethyl bromide, 2-chloropropane, 2-bromopropane, 2-iodopropane, dimethylamine, deuterated dimethylamine, dimethyl ether, deuterated dimethyl ether, 2,2-difluoropropane, deuterated acetone, hexafluoroacetone, trimethylamine, tertiary butyl cyanide, and tertiary butyl acetylene. Using absorption bands assigned to torsional vibrations, the height of the potential barrier for internal rotation is calculated and compared to the available microwave data.