Open-shell doublet character in a hexaazatrinaphthylene trianion complex.

Three-electron reduction of hexaazatrinaphthylene (HAN) with a magnesium(I) reagent leads to [(HAN){Mg(nacnac)}3] (1), containing a [HAN](3-) ligand with a spin of S = 1/2. Ab initio calculations reveal that the [HAN](3-) ligand in 1 has a ground-state wave function with multiconfigurational properties, and can be described as a triradicaloid species with a small amount of open-shell doublet character.