Reductive Deprotonation and Dehydrogenation of Phenylhydrazine at a Nickel Center To Give a Nickel Diazenido Complex

Abstract

The reaction of [L(tBu)Ni(OEt(2))] (where L(tBu) = [HC(C(t)BuNC(6)H(3)((i)Pr)(2))(2)](-)) with phenylhydrazine leads to the phenylhydrazido(1-) complex [L(tBu)Ni(η(2)-NPhNH(2))] (1) with concomitant formation of H(2). Treatment of 1 with potassium graphite in the presence of crown ether again leads to H(2) evolution and affords the heterobimetallic complex [L(tBu)Ni(μ-η(2):η(2)-NPhNH)]K(18-crown-6) containing the doubly deprotonated phenylhydrazido(2-) ligand. 1 can be converted into a phenyldiazenido complex [L(tBu)Ni(η(1)-NNPh)] in the course of a dehydrogenation reaction employing 1,2-diisopropylazo dicarboxylate (DIAD) as the oxidant.