Knowledge Bank

When $PF3$ or $PF5$ is subjected to Penning ionization and photoionization by excited neon atoms and their resonance radiation (16.6-16.8 eV) and the products are rapidly frozen in an excess of solid neon, the resulting solid deposit shows prominent infrared absorptions which can be assigned to cation and anion products, including $PF3+,PF4+$ and $PF4+$. Because phosphorus and fluorine each possess only one stable isotope, consideration of the spectra of related systems and of the results of ab initio calculations is important in making spectral assignments. Processes which lead to the stabilization of the observed ionic species will be discussed.