Self-Assembly of an Anionic [CuI] Supramolecular Cluster Driven by Ion-Pair Interaction and Catalytic Properties.

The rational design and controlling synthesis of an anionic cuprous iodide supramolecular cluster with high nuclearity through noncovalent interactions remains a significant challenge. Herein, a cationic organic ligand () was driven by anion-cation ion-pair electrostatic interaction to induce free cuprous iodide to aggregate into an anionic supramolecular cluster, [(CuI)()] (). Moreover, five copper(I) atoms bind with eight iodides through multiply bridged Cu-I bonds associated with intramolecular cuprophilic interactions in this butterfly-shaped cluster core. Supramolecular cluster exhibited a solid-state emission at 380 nm and an emission at 405 nm in acetonitrile at room temperature, respectively. Interestingly, this unprecedented cuprous iodide cluster demonstrated a good catalytic performance for azide-alkyne cycloaddition reaction (CuAAC) and the catalytic yield can be up to 80% for eight different substrates at 80 °C. Furthermore, the density functional theory (DFT) calculation revealed that the thermodynamic-dependent cycloaddition reaction underwent a four-step pathway with an overall energy barrier of -43.6 kcal mol on the basis of intermediates monitored by mass spectrum.