Atomically Precise Multimetallic Semiconductive Nanoclusters with Optical Limiting Effects

For the first time, multinuclear noble‐metal clusters have been successfully stabilized by Ti‐oxo clusters. Two unprecedented Ag₆@Ti₁₆‐oxo nanoclusters with precise atomic structures were prepared and characterized. The octahedral Ag₆ core has strong Ag?Ag bonds (ca. 2.7 Å), and is further stabilized by direct Ag?O?Ti coordination interactions. Moreover, as a result of different acidic/redox conditions in synthesis, the Ag₆ core can adopt diverse geometric configurations inside the Ti₁₆‐O shell. Correspondingly, structural differences greatly influence their optical limiting effects. The transmittance reduction activity of the clusters towards 532 nm laser shows a nearly linear concentration dependence, and can be optimized up to about 43 %. This work not only opens a new direction for multimetallic semiconductive nanoclusters with interesting optical properties, but also provides molecular models for important noble‐metal/TiO₂ heterogeneous materials.