The redox processes of the ligands analysed by the results obtained for −4ClO complexes (1, 3 and 5, Fig. 6a), show a shift to more positive values with the increase of bromide substituents at the phenolate ring. This can be attributed to the presence of electron withdrawing groups at the ring, restricting the electron density available at the ligand. For the −4BPh complexes (2, 4 and 6, Fig. 6b) it has to be noted that the anion itself can also be oxidised over the same potential window as the ligand (Fig. S1 of the Supporting information), challenging the clear identification of the processes involving both ligand and anion.