Electronic structure of two phosphorus compounds

The electronic structures of tri-2-furanyl-phosphine (I) and 1,2-bis(dimethoxyphosphoryl)benzene (II) have been investigated by HeI and HeII UV photoelectron spectroscopy (UPS) and quantum chemical calculations. Their electronic structures are discussed in the framework of their chemical properties and practical applications with special reference to the extent of intramolecular interactions. We have also rationalized the observed increased shielding of phosphorus in 31P NMR spectra of TFP.