0-Wurster Radical Cations and AnionsSeveral ring-substituted 1,2-phenylenediamines (2,4, 16, 17, 18) as well as their dihydrochlorides may be oxidized electrolytically or by lead dioxide to stable paramagnetic intermediates. Based on the e.s,r. spectra it is concluded that these radicals are cations of the o-Wurster type (C). Their diamagnetic reaction products were found to be am compounds and phenazines. -In the reaction of the phenylenediamines with diphenylthallium hydroxide in the presence of air oxygen the corresponding radical anions (E) are formed. These paramagnetic complexes exhibit a large thallium coupling and are probably ion pairs. The spin density distributed in the phenylenediamine radical cations and anions shows only small differences. -N, N, N', N'-Tetramethyl-1,2-phenylenediamines could not be oxidized under the conditions used. However, N-phosphoranylidene-1,2-phenyIenediamines (25 -27) form stable paramagnetic products after oxidation. These species are radical cations of the Wurster type, too.Brenzcatechine lassen sich im alkalischen Medium durch monovalente Oxidation in die entsprechenden Semichinonanionen A iiberfihren. Daraus entstehen durch eine formale Protonierung die analogen neutralen Aroxyle B, die durch weitere Addition eines Protons schlieDlich die Semichinonkationen-Radikale C bilden konnen. Die% drei Radikaltypen sind schon lange bekannt, und ihre chemischen und physikalischen Eigenschaften sind gut untersucht '). Die neutralen Oxidationsprodukte von o-Aminophenolen D wurden von uns vor einiger Zeit aufgefunden, und ihre spektroskopischen Eigenschaften sowie ihre Reaktionen mit zahlreichen Verbindungs-

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The ESR spectra of 4-oxyl-benzyl-phosphonium-bromide radicals show a temperature dependence of the methylene protons and the phosphorus nucleus coupling constants which is explained by a hindered rotation of the phenoxyl ring of the radicals. Furthermore compounds with different phosphor substituents exhibit the phenomenon of a two jump process. This effect is described by an isomerisation of two symmetric radical conformations. Activation energies for this process are found to be around 7 kcal/Mol. The conformation of the radicals can be discussed as staggered ethane analogues. A lower limit value for the hyperconjugation B p -parameter is proposed.

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