). The largest variation across all measurements is the HFC to the nitro nitrogen (Table ), with its magnitude |𝐴 𝑁 | being inversely proportional to the ionic radius of the alkali metal, in good qualitative agreement with our calculations (vide infra). The trend in |𝐴 𝑁 | is also inversely correlated to the HFC to the alkali ion, as previously observed, reflecting that when the electron spin participates over more centres, their overall interaction weakens. We also note a large variation in the |𝐴 𝑁 | and |𝐴 𝐻 𝑝 | parameters between contact and separated ion pair for the potassium-containing bases. While |𝐴 𝑁 | decreases from 10.6 to 9.4 Gauss, |𝐴 𝐻 𝑝 | increases from 3.9 to 4.1 Gauss for both KO t Bu and KHMDS (Figure -S18 and S20-S22). This is ascribed to the electron spin participating more effectively in all resonant forms of the aromatic ring when a distant ionic charge does not localise the spin density over the nitrogen atom. Finally, no other radicals have been measured in any of the experiments, suggesting that the lifetime of the oxidised species B • are too short to be detected. . More details are available in Table .