LATTICE VIBRATIONS OF PHOSPHONIUM CHLORIDE AND PHOSPHONIUM CHLORIDE-$d_{1}$ AND THE BARRIER TO TORSIONAL OSCILLATION.

Author Institution: Department of Chemistry, University of South CarolinaThe infrared spectra of polycrystalline $PH_{4}Cl$ and $PD_{4}Cl$ have been recorded from $33 cm^{-1}$ to $4000 cm^{-1}$ at $-170^{\circ}C$. Raman spectra of the two compounds were also obtained on poly-crystalline samples at the same temperature. Three external modes were observed: an infrared active translation at $140 cm^{-1}$, a Raman active translation at $114 cm^{-1}$ and a Raman active libration at $370 cm^{-1}$. Eight internal modes were also assigned. The barrier to torsional oscillation of the phosphonium ions was calculated from the Raman active libration and was found to be 8.5 kcal/mole for both $PH_{4}$ and $PD_{4}$ ions