Abstract
Complex redox pathways, like H‐atom transfer, hydride transfer, or O‐atom transfer, appear in the chemistry of polypyridyl complexes of ruthenium and osmium. These pathways provide a basis for the known activities of the complexes as electrocatalysts in the oxidation of organics, the interconversion of nitrite and ammonia, the oxidation of water to oxygen, the oxidation of Cl− to 
, and the interconversion of nitrate and nitrite.