The reaction of 2,2-diphenyl-1-picrylhydrazyl stable free radical with sodium tetra-phenylborate in the presence of 18-C-6 crown ether

The reaction between DPPH stable free radical and sodium tetraphenylborate in the presence of 18-C-6 crown ether affords the obtaining of the phenyl s hort lived free radical. The formation of the phenyl free radical was demon strated by spin-trapping with t-buthylphenylnitrone with the formation of t he corresponding nitroxide stable free radical, with characteristic ESR spe ctra. Other arguments in favour of the formation of phenyl free radical wer e: i) identification of the diphenyl resulted from phenyl radical dimerizat ion; ii) the formation of nitrogen dioxide by ipso-substitutive processes a nd iii) the formation of phenol, nitrobenzene and benzonitrile followed by the reactions conducted in the presence of NaOH, NaNO2 and NaCN.