A new N, O-bidentate, phenol–imidazole pro-ligand 2′-(4′, 6′-di-tert- butylhydroxyphenyl)-4, 5-diphenyl imidazole (LH) has been designed, synthesised, and characterised. LH possesses no readily oxidisable position (other than the phenol) and involves o-and p-substituents on the phenol ring that prevent radical coupling reactions. LH undergoes a reversible one-electron oxidation to generate the corresponding [LH]˙+ ...