Threefold Collaborative Stabilization of Ag14-Nanorods by Hydrophobic Ti16-Oxo Clusters and Alkynes: Designable Assembly and Solid-State Optical-Limiting Application

Ag nanoclusters have received increasing attention due to their atomically precise and diverse structures and intriguing optical properties. Nevertheless, the inherent instability of Ag nanoclusters has seriously hindered their practical application. In this work, for the first time, Ag clusters are collaboratively protected by hydrophobic Ti-oxo clusters and alkyne ligands. Initially, a pyramidal Ag-5 cluster terminated with (BuC)-Bu-t equivalent to C- and CH3CN was inserted into the cavity of a Ti-8-oxo nanoring to form Ag-5@Ti-8. To overcome the instability of acetonitrile-terminated silver site, such two Ag-5@Ti-8 clusters could sandwich an Ag-4 unit to form Ag-14-nanorod@Ti-16-oxo-nanoring (Ag-14@Ti-16), which is peripherally protected by fluorophenyl groups and alkyne caps. This threefold protected (hydrophobic fluorinated organic layer, Ti-O shell, and terminal alkyne ligands) Ag-14@Ti-16 exhibits superhydrophobicity and excellent ambient stability, endowing it with solid-state optical limiting characteristics.