In chemistry, a (redox) non-innocent ligand is a ligand in a metal complex where the oxidation state is unclear. Typically, complexes containing non-innocent ligands are redox active at mild potentials. The concept assumes that redox reactions in metal complexes are either metal or ligand localized, which is a simplification, albeit a useful one.
Read more about Non-innocent Ligand: Redox Reactions of Complexes Containing Innocent Vs. Non-Innocent Ligands, History, Typical Ligands That Often Behave As Redox Non-Innocent Ligands, Redox Non-Innocent Ligands in Organometallic Chemistry and Catalysis, Redox Non-Innocent Ligands in Biology, See Also