The computationally derived bond metrics of geometry-optimised 4d (4 with 3 THF molecules bound to Mg) and 5 (see ESI Figure ) further corroborated our observations from NMR-spectroscopy and the X-ray crystal structure. The alternating single/double C-C bonds observed throughout the naphthyridine backbone found for 4d are consistent with a four-electron reduced ligand featuring two bis-anionic NN pockets. The calculated bond metrics of 5 match the experimental bond metrics well (see ESI Figure ) and support the description of a two-electron reduced naphthyridine-imine ligand with a delocalised anionic charge over the N1-C6-N2 motif.