The number of resonances in the 1 H-and Storing a saturated THF/pentane solution of 5 at -40 °C yielded dark needle-shaped crystals suitable for X-ray diffraction (Figure ). The solid-state structure revealed a distorted trigonal bipyramidal geometry around the Mg centres, with each butyl group bridging the Mg centres. The apical positions of the bipyramids are occupied by the N-donor of the naphthyridine ring and by a O-donor from THF. The 1:1 ratio between coordinated THF and Mg in the solid-state structure is consistent with earlier observations in solution. The N3-Mg1-C35 and N3-Mg1-C39 angles (125.10(15)° and 129.42(15)° respectively) are enlarged, whilst the C35-Mg1-C39 angle (104.92(15)°) is contracted compared to ideal trigonal bipyramidal geometry, with similar trends observed for the second Mg centre (τ = 0.65 and 0.71, respectively). The Mg1-Mg2 distance (2.7499(18) Å) and Mg-C bond lengths (2.302(4)-2.321(4) Å) align with metrics reported for crystallographically characterised Mg 2 -alkyl 2 species with a similar "diamondcore". The observation of the preferential formation of this core over deprotonation of the relatively acidic methylene protons is most likely attributed to the bridging binding mode of the butyl groups, which delocalises their negative charge and renders them less basic. The Mg-C bond lengths are slightly longer than in most of these structures and likely reflect the THF coordination and higher electronic saturation of the Mg centres. The bond lengths of Mg1-N3 and Mg2-N4 (2.022(3) and 2.020(4) Å respectively) are considerably shorter than the Mg1-N1 and Mg2-N2 bonds (2.247(3) and 2.220(3) Å respectively), which is in line with their higher anionic character. We explored if the dibutyl-magnesium chemistry observed for the dipp DAMN ligand also translated to the dipp NDC ligand. Reacting a benzene solution of dipp NDC with 2 equiv of Mg(n-Bu) 2 resulted in effervescence and a dark green solution. Interestingly, 1 H NMR analysis of the reaction mixture revealed the formation of an NMR-silent species (see ESI Figure ), contrasting the described reactivity with dipp DAMN. Despite repeated attempts, we were unable to grow single crystals suitable for analysis by X-ray diffraction out of the reaction mixture. To better understand the nature of the complexes formed, we quenched the reaction mixture with water (see ESI Section 1.11). H-NMR analysis (C 6 D 6 , 298 K) after the aqueous work-up revealed multiple resonances, consistent with the formation of several compounds. Of particular interest were the resonances between δ = 5.91 and 4.85 ppm, consistent with protons on dearomatised pyridine rings. The 1 H-1 H COSY NMR spectrum (see ESI Figure ) showed coupling between the resonance at δ = 4.85 ppm and a doublet at δ = 3.23 ppm, obfuscated by the -dipp -CH septets. These shifts are similar to those reported for the 3-and 4-positions of a para-coupled bisnaphthyridine system (δ = 5.0 and 3.4 ppm respectively, in toluene-d 8 ). Such para-coupling arises from the radical recombination of naphthyridine-centred radicals, as observed for dinickel complexes (Uyeda group) and dicopper complexes (Tilley group). Combining these data, we propose that a dipp NDCMg 2 (n-Bu) 2 species initially forms, with the observed effervescence arising from butane liberation. Consistent with previous observations, we expect that the ligand will be in the imidate form. This complex most likely undergoes Mg-C homolysis, similar to what is observed for dialkylmagnesium complexes bound to conjugated diimines, bis-pyridines, and di-iminopyridines. DFT calculations on truncated LMg 2 Me 2 models (see ESI Sections 2.4-2.7) reveal a Gibbs free energy difference of 38.3 kcal•mol -1 between the singlet and triplet states of the dipp DAMN-based complex. In contrast, the same difference for the dipp NDC-based complex is only 20.8 kcal•mol -1 , making it thermally accessible at room temperature. Notably, the geometry optimisation of the triplet state of dipp NDCMg 2 Me 2 •4 THF consistently resulted in extrusion of a methyl radical (see ESI Figure ), highlighting the energetically facile nature of Mg-C homolysis in this case. For reported mononuclear complexes with pyridine-based ligands, homolysis of M-C bonds (M = Li, Mg, Al, Zn) often leads to alkylation of various positions of the pyridine, including the pyridinic nitrogen. This process is proposed to occur via single-electron transfer from the Mg-C bond to the pyridine backbone, followed by radical recombination with the liberated alkyl radical (Scheme 8, left). If the alkyl radical escapes the solvent cage, the resulting ligand-centred radicals can reversibly dimerise (Scheme 8, right). In these literature examples, both alkylation and dimerisation products are diamagnetic, which contrasts with our observations for the dipp NDC ligand. We propose that the observed paramagnetism results from the extended conjugated system of the dipp NDC ligand, which stabilises ligand-centred radicals better than the mononuclear analogues, and pushes the alkylation and dimerisation equilibria toward the ligand-centred radical side (Scheme 8). Whilst the exact nature of the species formed in this reaction remains elusive, the combined NMR and ESI-MS data suggest a complex mixture of products, including butylated and coupled derivatives of the dipp NDC ligand. These products arise from the generated butyl radical being either trapped by or escaping the solvent cage, respectively.