Ag20 Nanoclusters with Surface Azides as an Easily Functionalized Platform for Diverse Chemical Applications

Modifying atomically precise nanocluster surfaces while maintaining the cluster core remains a key challenge. Herein, the synthesis, structure, and properties of two targeted Ag20 nanoclusters (NCs) with eight surface azide moieties, [CO3@Ag20(StBu)10(m‐N3‐C6H4COO)8(DMF)4] (1‐m) and [CO3@Ag20(StBu)10(p‐N3‐C6H4COO)8(DMF)4] (1‐p) are reported, where DMF is N,N‐dimethylformamide. These AgNCs are designed to undergo cluster surface strain‐promoted azide‐alkyne cycloaddition (CS‐SPAAC) reactions, introducing new functionality to the cluster surface. Reactivity is screened using model strained cyclooctynes. Reaction products and parent clusters are characterized by UV–vis, FT‐IR, and NMR spectroscopies. The structure of the parent clusters and presence of surface azides is confirmed by single crystal X‐ray diffraction (SCXRD) analysis. Clusters 1‐m and 1‐p are found to be amenable to CS‐SPAAC reactions with retention of the NC frameworks, opening new routes for efficient modification of AgNC for applications. Surface modification on atomically precise silver nanoclusters has always presented a challenge to their potential broad applicability as materials. In this work, two Ag20 nanoclusters with surface azides are presented. They can undergo strain‐promoted azide‐alkyne cycloaddition reactions. Using model‐functionalized cyclooctynes, the surface functionality of the nanoclusters can be quickly and easily changed while retaining the core structure.