OXIDIZED PHENYL-SUBSTITUTED SESQUIBICYCLIC HYDRAZINES

The effect of alpha- and beta-phenyl substituents on the neutral, +1, and +2 oxidation states of bis-N,N'-bicyclic hydrazines 1 and 2 is dis cussed. An alpha-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 de localization into the phenyl groups of the +1 oxidation states of thes e compounds. Exo and endo beta-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 unsub stituted 1, which is argued to demonstrate that attaining relative ori entations which allow overlap of the dinitrogen pi systems at the tran sition state cannot be important; electron transfer proceeds through t he alkyl groups. The dications XPh-2(2+) and nPh-2(2+) decompose in ac etonitrile much faster than 2(2+) (room temperature lifetimes < 1 s fo r the phenylated compounds and > 10(4) min for the parent).