Atomically Precise Site-Specific Tailoring and Directional Assembly of Superatomic Silver Nanoclusters

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<sub>14</sub> superatoms protected by face-capping 1,2-dithiolate-<i>o</i>-carborane (C<sub>2</sub>B<sub>10</sub>H<sub>10</sub>S<sub>2</sub>) ligands, each produced from 1-thiol-<i>o</i>-carborane in crystallization with simultaneous reduction of Ag<sup>+</sup> to Ag<sup>0</sup>. We find that the corner N-donor ligands contribute predominately to the stability and luminescence of the Ag<sub>14</sub> superatom. As the first-formed nanocluster [Ag<sub>14</sub>(C<sub>2</sub>B<sub>10</sub>H<sub>10</sub>S<sub>2</sub>)<sub>6</sub>(CH<sub>3</sub>CN)<sub>8</sub>]·4CH<sub>3</sub>CN (<b>NC-1</b>) with labile vertex-coordinated CH<sub>3</sub>CN ligands is highly unstable, monodendate pyridine ligands were used to replace these CH<sub>3</sub>CN species site-specifically, giving [Ag<sub>14</sub>(C<sub>2</sub>B<sub>10</sub>H<sub>10</sub>S<sub>2</sub>)<sub>6</sub>(pyridine/<i>p</i>-methylpyridine)<sub>8</sub>] (<b>NCs-2,3</b>) 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<sub>14</sub> building blocks, we constructed an unprecedented hierarchical series of 1D-to-3D superatomic silver cluster-assembled materials (<b>SCAM-1,2,3,4</b>), and <b>SCAM-4</b> 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.