An Ultrastable, Small {Ag₇ }⁵⁺ Nanocluster within a Triangular Hollow Polyoxometalate Framework

Area of Science:

• Nanomaterials Science
• Inorganic Chemistry
• Materials Chemistry

Background:

• Small silver nanoclusters (Ag_n, n<10) show potential in sensing, biolabeling, and catalysis due to unique electronic and optical properties.
• Low stability of small silver nanoclusters hinders their synthesis, structure determination, and property exploration.

Purpose of the Study:

• To synthesize a novel, ultrastable small silver nanocluster.
• To characterize the structure and properties of the synthesized nanocluster.
• To investigate the potential applications of the stable nanocluster.

Main Methods:

• Synthesis of an atomically precise face-centered-cubic-type {Ag₇ }⁵⁺ nanocluster.
• Support of the nanocluster by a novel triangular hollow polyoxometalate (POM) framework, [Si₃ W₂₇ O₉₆ ]^18-.
• Characterization of optical properties, including charge transfer bands.

Main Results:

• Successful synthesis of a stable {Ag₇ }⁵⁺ nanocluster encapsulated within a POM framework.
• Observation of unique {Ag₇ }⁵⁺-to-POM charge transfer bands in visible and UV regions.
• Demonstration of unprecedented ultrastability in solution, with accessible Ag sites.

Conclusions:

• The novel POM-supported {Ag₇ }⁵⁺ nanocluster offers enhanced stability for practical applications.
• The unique electronic and optical properties, coupled with stability, make it a promising material for sensing, biolabeling, and catalysis.
• This work overcomes previous limitations in studying small nanoclusters due to instability.