Knowledge Bank

The rotational spectra of $CF3PH2,CF3PHD$, and $CF3PD2$ have been observed and analyzed. Splitting of the lines due to internal rotation of the methyl group was observed in the transitions of the ground state and in the transitions of the first excited state, leading to a calculated barrier height of $2,360\pm 80$ cal/mole. The dipole moment components are $\mu a=1.77\pm .01D\mu e=0.74\pm .03D$ and $\mu total=1.92\pm .02D$. The structural parameters have been determined and will be discussed.