Knowledge Bank

The infrared spectrum of gaseous $H2S2,CF3SH$ and $CF3SD$ has been observed down to $100cm-1$. From the observed torsion frequencies, the barriers hindering internal rotation are suggested as about $2400cm-1$ for $H2S2$, and $425cm-1$ for $CF3SH$. The potential function implies that the dihedral angle of $H2S2$ is close to $90\circ$. The fundamental frequency assignments of $CF3SH$ are discussed.