N -Heterocyclic Phosphorus Compounds Based on N , N '-Disubstituted 9,10-Phenanthrenediimines

N -Heterocyclic phospholes based on N , N '-disubstituted 9,10-phenanthrenediimines have been synthesized for the first time. Dimeric 1,3,2-diazaphospholes have been obtained by the reduction of 2-bromodiazaphospholes. In the case of the most sterically hindered phenanthrenediimine, diphosphole can dissociate into phosphorus-centered radicals at extremely low temperatures (220 K) for this class of compounds, which makes it possible to synthesize new organophosphorus and coordination compounds under mild conditions.