COMPOUNDS FEATURING THE STRUCTURAL FRAGMENT P-C-P

This article summarizes some of our investigations of compounds featuring the structural fragment P-C-P. Phosphorus atoms in different oxidation states and coordination numbers display different chemical behaviors. This may lead to unique chemical properties when they are bridged by a methylene group in a P-CH2-P system. For example, the P-III-CH2-P(V)unit is able to add different unsaturated compounds to give zwitterionic products with oppositely charged phosphorus atoms. In addition, the two hydrogen atoms in P-CH2-P may also take part in different transformations, resulting in the formation of carbodiphosphoranes or in the formation of a direct P-P bond to give three-membered ring diphosphiranes.