Atomically Precise Clusters of Noble Metals: Emerging Link between Atoms and Nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Atomically precise noble metal clusters are novel nanomaterials with unique properties.
• Over 100 different cluster formulas are known, including gold and silver compounds.
• These materials are distinct from nanoparticles due to their molecular characteristics.

Purpose of the Study:

• To review the synthesis, properties, and applications of atomically precise noble metal clusters.
• To highlight their molecular nature and potential in various scientific fields.
• To introduce a nomenclature for understanding their complex structures.

Main Methods:

• Reproducible synthesis protocols yielding colored solutions, powders, or crystals.
• Spectroscopic analysis (optical absorption, emission) revealing molecular-like features.
• Mass spectrometry for isotopically resolved molecular ion peaks.
• Diverse instrumental methods for characterization.

Main Results:

• Clusters exhibit unique spectroscopic properties, including luminescence in the visible-near-infrared window.
• Luminescence is utilized in sensitive detection applications for molecules and ions.
• Catalytic properties, particularly in organic substrate oxidation, have been investigated.
• Computational studies explain their stability and unusual behaviors.

Conclusions:

• Atomically precise noble metal clusters are best described as 'shielded molecules' (aspicules).
• Their properties arise from the core, ligand shell, and integrated system.
• Ongoing research in materials science and computational insights continues to evolve this field.