A New Domain of Reactivity for High-Valent Dinuclear [M(μ-O)2 M'] Complexes in Oxidation Reactions

Abstract

The strikingly different reactivity of a series of homo- and heterodinuclear [(M^III )(μ-O)₂ (M^III )']²⁺ (M=Ni; M'=Fe, Co, Ni and M=M'=Co) complexes with β-diketiminate ligands in electrophilic and nucleophilic oxidation reactions is reported, and can be correlated to the spectroscopic features of the [(M^III )(μ-O)₂ (M^III )']²⁺ core. In particular, the unprecedented nucleophilic reactivity of the symmetric [Ni^III (μ-O)₂ Ni^III ]²⁺ complex and the decay of the asymmetric [Ni^III (μ-O)₂ Co^III ]²⁺ core through aromatic hydroxylation reactions represent a new domain for high-valent bis(μ-oxido)dimetal reactivity.

Keywords: NIH shift; dioxygen activation; heterobimetallic complex; metal-oxo complexes; nucleophilic oxidant.