Viewing inorganic metal nanoclusters through the lens of molecular chemistry

Few- to hundred-atom-composed metal nanoclusters (NCs) lie in the transition regime between molecular- and nanometer-scales and have attracted intensive attention for their emerging molecule-like properties that energetically serve various sectors of applications. We here deploy this review in a novel viewpoint, namely the emphasis on the diverse molecule-like properties of metal NCs. We start to clarify the uniqueness in size, precision in total structure, and diversity in species of the molecularly pure metal NCs. This poses the origin of their molecule-like performances. Specifically, it in sequence involves the reminiscent concepts coined in molecular science (i.e., chirality, isomerization, and total synthesis); the most impressive molecule-like optical properties; the emergence of DNA-like helical ensembles mimicking biomolecules and their assemblies. We also provide our perspectives on future molecule-like NCs research, focusing on their fundamental importance and practical value. This review is expected to provide a brand-new viewpoint to revisit the science of metal NCs, by deepening the concept of the metallic molecule and admiring the molecule-like features of metal NCs, which may feed the new vitality and flavors to the various sections of fundamentals and applications in the future.