Photoelectron spectroscopy of some chlorinated phosphate esters

The electronic structures of ethylenephosphochloridate, 1,2-phenylenephosphochloridate and 2,2,2-trichloro-1,3,2-benzodioxaphosphole have been studied by HeI/HeII photoelectron spectroscopy (UPS) and Green's function calculations. Our results indicate the importance of hyperconjugative interactions between the 5-membered ring and the fused aromatic ring. Some implications of our results for rates of nucleophilic substitution reactions on phosphorus are discussed.