Nitroxide radicals formed by addition of phosphorus-centred radicals to aliphatic oximes. An electron paramagnetic resonance study

Pentavalent phosphorus-centred radicals are found to add to some aliphatic oximes to give rather persistent paramagnetic adducts which, on the basis of their spectral parameters, have been identified as hydronitroxides containing a ?-phosphorus substituent. Prolonged photolysis results in the observation of phosphonitroxides, whose formation is believed to proceed through addition of phosphorus-centred radicals to a nitroso derivative formed in situ.