A new β-diiminate ligand (the bis(1-methyl-4,5-diphenyl-1H-imidazol-2-yl)methane anion, BMIM ) is introduced, in which the ligand framework bears an extended imidazole-based π-system in conjugation with a formal β-diketiminates (NacNac) backbone. Bis-ligated transition metal complexes (Co, Zn) featuring this anionic ligand undergo a series of four consecutive single-electron oxidations that are all ligand-based. The singly and doubly oxidized complexes can be synthesized on a preparative scale and have been fully characterized by various spectroscopic techniques. This is in sharp contrast to the corresponding NacNac-based complexes in which only singly oxidized complexes were isolated and characterized. Single crystal X-ray structure determination revealed a correlation between the intra-ligand metrical parameters and the oxidation state of BMIM . These structural changes in the ligand framework make BMIM as a perceptible non-innocent ligand in contrast to NacNac type ligands.

The first example of a redox non‐innocent β‐diketiminate‐type ligand, bis(1‐methyl‐4,5‐diphenyl‐1H‐imidazol‐2‐yl)methane anion, BMIMPh2−, is presented. In homoleptic metal complexes, these ligands are susceptible toward oxidation, covering three different oxidation states. The redox behavior of complexes featuring BMIMPh2− or related ligands are expected be a versatile tool in contemporary research within the context of chemical catalysis or activation of small molecules. More information can be found in the Communication by R. J. M. Klein Gebbink et al. on page 10732. (Background illustration: Invisible_studio – Freepik.com; Scientific figures: P. Ghosh).