Scalar interactions in phosphorus-31 systems as studied by dynamic nuclear polarization

Abstract
The nuclear-electron Overhauser effect has been investigated at two magnetic fields for phosphorus III and phosphorus V systems. The results are interpreted in terms of a scalar interaction between the phosphorus nuclei and the radical electron, which is more pronounced in phosphorus III compounds. The mechanisms for the interaction are discussed, and it is shown that steric hindrance accounts for the difference in this interaction between the two oxidation states.