Reactivity of a Nickel(II) Bis(amidate) Complex withmeta-Chloroperbenzoic Acid: Formation of a Potent Oxidizing Species

Herein, we report the formation of a highly reactive nickel–oxygen species that has been trapped following reaction of a NiII precursor bearing a macrocyclic bis(amidate) ligand with meta-chloroperbenzoic acid (HmCPBA). This compound is only detectable at temperatures below 250 K and is much more reactive toward organic substrates (i.e., C[BOND]H bonds, C[DOUBLE BOND]C bonds, and sulfides) than previously reported well-defined nickel–oxygen species. Remarkably, this species is formed by heterolytic O[BOND]O bond cleavage of a Ni–HmCPBA precursor, which is concluded from experimental and computational data. On the basis of spectroscopy and DFT calculations, this reactive species is proposed to be a NiIII–oxyl compound.