Abstract
<jats:title>Abstract</jats:title> <jats:p>In the early 1990s, it was discovered that the phenoxyl radical can bind with a metal ion as an open‐shell ligand performing the role of an organic radical cofactor in a metalloenzyme, galactose oxidase (GO), which is a single copper oxidase catalyzing the two‐electron oxidation of a primary alcohol to the aldehyde. After this discovery, the phenolate moiety in metal complexes has become one of the most famous and important redox‐active ligands, and the oxidation of metal–phenolato complexes sometimes gives the metal–phenoxyl radical complexes. The number of phenoxyl radical–metal complexes has been increased, and the properties and reactivity of such complexes have been widely developed in recent years.</jats:p> <jats:p>This chapter focuses on recent developments in the synthesis, structure, properties, and reactivity of metal–phenoxyl radical complexes, especially their detailed electronic structures and reactivities.</jats:p>