Inside Back Cover: A Stable Aminyl Radical Coordinated to Cobalt (Chem. Eur. J. 28/2017)

Transition-metal-coordinated radicals can be hard to classify because the unpaired electron may be localized on the metal, the ligand, or delocalized on both. In metal complexes from the fourth period, with classical N- or O-donor sites, the unpaired spin density is frequently on the metal. The paramagnetic cationic cobalt complex [Co(trop2N)(bpy)]+ may be described as a CoII amido complex or a CoI aminyl radical. EPR and DFT data show that the spin density is evenly distributed on N1 (ρ=55%) and Co (ρ=51%) and not mainly on the metal. This study indicates that non-innocent olefinic binding sites as ligands lead preferably to delocalized electronic structures. More information can be found in the Full Paper by B. de Bruin, M. Trincado, H. Grützmacher et al. on page 6795 ff.