Low Valent Palladium Clusters: Synthesis, Structures and Catalytic Applications

Abstract

As one of the most common transition metal catalysts, mononuclear palladium catalysts have been developed systematically and a widely recognized catalytic mechanism featured with a Pd0/PdII catalytic cycle for a palladium center has been proposed. However, recent research works have revealed that palladium clusters may also be catalysts or catalytic intermediates involved in the catalytic processes. This major discovery brings new perspectives for a deep and comprehensive understanding of the Pd‐catalyzed reaction mechanisms. Combining with the latest advances in the field of organometallic chemistry, we here highlight the synthesis, structures, and catalytic reactivities of palladium cluster compounds. This review discusses several well‐defined synthetic strategies and diverse palladium cluster‐based catalytic systems in detail, to provide insights into the rational design of promising palladium cluster catalysts and the effective search for appropriate synthetic methods.