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/Pd^II 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.

中文翻译：

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低价钯簇：合成，结构和催化应用。

作为最常见的过渡金属催化剂之一，已经系统地开发了单核钯催化剂，并以Pd ⁰ / Pd ^II为特征广泛认可的催化机理。已经提出了钯中心的催化循环。但是，最近的研究工作表明，钯簇也可能是催化过程中涉及的催化剂或催化中间体。这一重大发现为深入，全面地了解Pd催化的反应机理提供了新的视角。结合有机金属化学领域的最新进展，我们在这里重点介绍钯簇化合物的合成，结构和催化反应活性。这篇综述详细讨论了几种定义明确的合成策略和各种基于钯簇的催化体系，从而为有前途的钯簇催化剂的合理设计和有效寻找合适的合成方法提供了见识。