SPECTRA OF FLUORINE-CHLORINE SUSTITUTED TRIVALENT PHOSPHORUS

This work was supported by the Robert A. Welch FoundationAuthor Institution: Department of Chemistry, North Texas State UniversityThe electronic spectra of the fluorine and chlorine substituted trivalent phosphorus have been measured in the vapor phase between 2000 and ca. $1200^{\circ}$ \AA. Systematic replacement of fluorine by chlorine in $PF_{3}$ $(PF_{3}$, $PF_{2} $Cl, $PFCl_{2}$ and $PCl_{3}$) corresponds to a noticeable increase in the number of absorption maxima. The spectral trends are considered in terms of the electron-withdrawing properties of the respective halogens. Specific consideration of the chlorine and phosphorus non-bonding electrons and their contributions to the spectral absorptions are made. The assignments will be discussed utilizing the reslts of a CNDO molecular orbital calculation