Oxidized Phenyl−Substituted Sesquibicyclic Hydrazines

The effect of a− and P−phenyl substituents on the neutral, +1, and +2 oxidation states of bis−N,N&#39;− bicyclic hydrazines 1 and 2 is discussed. An a−phenyl substituent on 2 makes first electron removal 1.8 kcal/mol more difficult, but second electron removal 3.2 kcal/mol less difficult. There is no evidence for significant spin or charge delocalization into the phenyl groups of the +1 oxidation states of these compounds. Exo and endo 8−phenyl−substituted hydrazines xPh−1 and nPh−1 have electron transfer rate constants between their neutral and radical cation forms which are 85% and 55% as large as that for unsubstituted 1, which is argued to demonstrate that attaining relative orientations which allow overlap of the dinitrogen n systems at the transition state cannot be important; electron transfer proceeds through the alkyl groups. The dications ˜ P h − 2 ˜ ˜ and nPh− 22+ decompose in acetonitrile much faster than 22+ (room temperature lifetimes < 1 s for the phenylated compounds and > lo4 min for the parent