摘要
It was found and reported for the first time by one of the present authors in 1963 that the reduction of 2, 3, 5-triphenyltetrazolium chloride or the oxydation of 1, 3, 5-triphenylformazan in solution gave rise to a stable free radical. A new, free radical with bi-valence nitrogen atom, it is stable in air. The reaction is shown as follows: