An Isolable, Nonreducible High-Valent Manganese(V) Imido Corrolazine Complex

The manganese(V) imido complex [(TBP₈Cz)Mn^V(NMes)] (2) was synthesized from the Mn^III complex [(TBP₈Cz)Mn^III] (1) and thermolysis of mesityl azide. An X-ray structure of 2 reveals a short Mn−N distance [1.595(4) Å], consistent with the Mn−N triple bond expected for a manganese(V) imido species. This high-valent species is remarkably inert to one- and two-electron reductive processes such as NR group transfer to alkenes or H-atom abstraction from O−H bonds. Electrochemical studies support this lack of reactivity. In contrast, oxidation of 2 is easily accomplished by treatment with [(4-BrC₆H₄)₃N]^•+SbCl₆, giving a π-radical-cation complex.