Metal Complexes of Aminyl Radicals

摘要

Transition-metal complexes with open-shell configurations typically have their spin density more or less confined to the metal ion: the unpaired electron (or electrons) resides in metal-based d orbitals, and there is minimal delocalization onto the ligands that comprise the inner coordination sphere of the complex. Metal complexes in which an unpaired electron resides on a ligand are relatively rare but are by no means unknown or unimportant. Semiquinone anions and phenoxyls are two examples of well-known radical ligands, both of which are delocalized π radicals which bind to metals through oxygen atoms. Both of these classes of radical ligands have attracted significant attention because of their importance in bioinorganic chemistry and their interesting physical properties.