β-Diketiminates as Redox Non-innocent Supporting Ligands in Coordination Chemistry

Abstract

Recent studies of redox non-innocence of β-diketiminate ligands are introduced. Reduction of Yb3+ and Al3+ as well as Li+ and Be2+ complexes using strong electron-transfer reductants induces the ligand-based one- and/or two-electron reduction, whereas electron-transfer oxidation of bis(β-diketiminato)-Ni2+ complexes gives Robin and Day class III mixed-valence complexes, having an unpaired electron completely delocalized between the two ligands. Furthermore, a new trianionic tetradentate ligand is developed by introducing two phenolate moieties on the nitrogen atoms of a β-diketiminate ligand to mimic the active site of galactose oxidase. In the copper(II) complex of this ligand, oxidation reaction also takes place at the ligand moiety to provide phenoxyl–copper(II) complexes.