Convenient generation of stable superatomic silver clusters and their systematic site-specific tailoring and directional assembly present an enduring and significant challenge. In this work, we prepared a face-centered cubic (fcc) array of Ag superatoms protected by face-capping 1,2-dithiolate-o-carborane (CBHS) ligands, each produced from 1-thiol-o-carborane in crystallization with simultaneous reduction of Ag to Ag. We find that the corner N-donor ligands contribute predominately to the stability and luminescence of the Ag superatom. As the first-formed nanocluster [Ag(CBHS)(CHCN)]·4CHCN (NC-1) with labile vertex-coordinated CHCN ligands is highly unstable, monodendate pyridine ligands were used to replace these CHCN species site-specifically, giving [Ag(CBHS)(pyridine/p-methylpyridine)] (NCs-2,3) in gram scale with its core structure intact, which features ultrastability up to 150 °C in air. Moreover, using bidentate N-containing ligands to bridge the superatomic Ag building blocks, we constructed an unprecedented hierarchical series of 1D-to-3D superatomic silver cluster-assembled materials (SCAM-1,2,3,4), and SCAM-4 is air-stable up to 220 °C. Furthermore, this series of stable solid-state superatomic-nanocluster materials exhibit tunable dual emission with wide-range thermochromism. The present study constitutes a major step toward the development of ligand-modulation of the structure, stability, assembly, and functionality of superatomic silver nanoclusters.

Gold nanoclusters have become promising radiosensitizers due to their ultrasmall size and robust ability to adsorb, scatter, and re-emit radiation. However, most of the previously reported gold nanocluster radiosensitizers do not have a precise atomic structure, causing difficulties in understanding the structure–activity relationship. In this study, a structurally defined gold–levonorgestrel nanocluster consisting of Au8(C21H27O2)8 (Au8NC) with bright luminescence (58.7% quantum yield) and satisfactory biocompatibility was demonstrated as a nanoradiosensitizer. When the Au8NCs were irradiated with X-rays, they produced reactive oxygen species (ROS), resulting in irreversible cell apoptosis. As indicated by in vivo tumor formation experiments, tumorigenicity was significantly suppressed after one radiotherapy treatment with the Au8NCs. In addition, compared with tumors treated with X-rays (4 Gy) alone, tumors treated with the nanosensitizer exhibited an inhibition rate of 74.2%. This study contributes to the development of atomically precise gold nanoclusters as efficient radiosensitizers.

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The fluorescent properties of atomically precise nanoclusters have been regulated by solvent-induced atomic structure transformation and cationic polymer-induced self-assembly for cell imaging and drug delivery.

Prospects in light‐driven water activation have prompted rapid progress in hydrogenation reactions. We describe a Ni2+−N4 site built on carbon nitride for catalyzed semihydrogenation of alkynes, with water supplying protons, powered by visible‐light irradiation. Importantly, the photocatalytic approach developed here enabled access to diverse deuterated alkenes in D2O with excellent deuterium incorporation. Under visible‐light irradiation, evolution of a four‐coordinate Ni2+ species into a three‐coordinate Ni+ species was spectroscopically identified. In combination with theoretical calculations, the photo‐evolved Ni+ is posited as HO−Ni+−N2 with an uncoordinated, protonated pyridinic nitrogen, formed by coupled Ni2+ reduction and water dissociation. The paired Ni−N prompts hydrogen liberation from water, and it renders desorption of alkene preferred over further hydrogenation to alkane, ensuring excellent semihydrogenation selectivity.