Photoelectron spectroscopy of phenyldihalophosphites

In order to explain the reactivity of aryldihalophosphites towards halophosphomum salts, photoelectron spectra of PhOPX2 (X=F, Cl) were studied. Electron densities of boundary molecular orbitals (MO) for these compounds were calculated using the MNDO method and analyzed. Replacement of F by Cl was shown to substantially affect the σ orbital. When X= Cl, this MO embraces the whole of the OPX2 moiety whereas for X=F it is localized on the P-O bond.