Catalytic reactivity of a zirconium(IV) redox-active ligand complex with 1,2-diphenylhydrazine

Two-electron reactivity of [N2O2red]ZrL3 (1a, N2O2red = N,N-bis(3,5-di-tert-butyl-2phenoxy)-1,2-phenylenediamide, L = THF) was explored with halogens and 1,2-diphenylhyrazine. Despite a formal do zirconium(M metal center, halogen oxidative addition occurred to form [N2O2ox]ZrCl2(THF)(2) with two-electron oxidation of the ligand. This ligand redox activity allows catalytic reactivity with 1,2-diphenylhydrazine resulting in disproportionation to form aniline and azobenzene via a putative zirconium-imide intermediate.