Stability and equilibria of free radicals—III Preparation of stable, sterically shielded, diarylnitrogen radicals with donor and acceptor aryl groups in the same molecule

Diarrylamines ArNHAr′ (Ar = 2,4,6-tri-, 2,6-di- or 2,4-dinitrophenyl, and Ar′ = phenyl or a phenyl with electron-donating substituents) were prepared; their IR and UV spectra, electrooxidation and electroreduction potentials were studied. Oxidation of picryl- and 2,6-dinitrophenyl-substituted compounds with Ag₂O affords paramagnetic solution giving ESR signals with Ar′ has MeO or NR₂ substituents. Radicals IVi and Vi are stable even in crystalline state.