Bimetallic Ag₁₂₅Cu₈ Nanocluster, Structure Determination, and Nonlinear Optical Properties.

Area of Science:

• Nanomaterials Science
• Inorganic Chemistry
• Physical Chemistry

Background:

• Subnanometer nanoclusters bridge the gap between metal complexes and nanoparticles.
• Understanding structure-property relationships in bimetallic nanoclusters is crucial.

Purpose of the Study:

• To synthesize and characterize the largest Ag-Cu bimetallic nanocluster reported to date.
• To elucidate its atomic structure, electronic configuration, and optical properties.

Main Methods:

• Synthesis and single-crystal X-ray diffraction for structural determination.
• Electron paramagnetic resonance (EPR) for electronic structure analysis.
• Differential pulse voltammetry (DPV) for electrochemical characterization.
• Z-scan technique for nonlinear optical absorption measurements.

Main Results:

• Successfully synthesized Ag125Cu8(m-MBT)57Cl3, the largest Ag-Cu bimetallic cluster.
• Revealed a three-layer core-shell structure (Ag7@Ag47@Ag71Cu8) with D5 symmetry.
• Demonstrated an open electron shell with 73 delocalized electrons.
• Observed unique electrochemical behavior and significant nonlinear optical absorption in the NIR-II/III region.

Conclusions:

• The study establishes a new size record for Ag-Cu bimetallic clusters.
• The findings highlight the importance of atomic precision in designing functional nanomaterials.
• The unique structural and electronic properties suggest potential applications in catalysis and optics.