O₂ Activation by a Heterobimetallic Zr/Co Complex

Oxygen reduction is a critical half reaction in renewable fuel cell development and a key step in the development of aerobic oxidation reactions. Herein, we report rapid two-electron O₂ reduction by a d⁰ Zr^IV center with an appended redox-active Co^-I site serving as an electron reservoir. The early/late heterobimetallic Zr/Co complex (THF)Zr(MesNP ⁱPr₂)₃CoCN ^tBu (1) reacts readily with O₂ and O atom transfer reagents to generate reactive oxygenated species including terminal peroxo and oxo complexes, (O₂)Zr(MesNP ⁱPr₂)₃CoCN ^tBu (2) and O≡Zr(MesNP ⁱPr₂)₃CoCN ^tBu (3). The bimetallic Zr/Co complex provides a new cooperative synthetic pathway to promote multielectron redox processes such as oxygen reduction, with each metal playing a distinct role as a substrate binding site or redox mediator.