Fluorescent Gold Nanoclusters with Interlocked Staples and a Fully Thiolate-Bound Kernel

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• The intrinsic fluorescence of gold nanoclusters is not well understood.
• Determining the structure of fluorescent gold nanoclusters is crucial for understanding their properties.

Purpose of the Study:

• Synthesize and characterize novel fluorescent gold nanoclusters.
• Elucidate the structure-fluorescence relationship in Au24(SR)20 nanoclusters.

Main Methods:

• Synthesis of three distinct Au24(SR)20 nanoclusters.
• Structural analysis using UV/Vis/NIR, differential pulse voltammetry (DPV), and X-ray absorption fine structure (XAFS).

Main Results:

• All three synthesized nanoclusters exhibited similar structures.
• The determined structure features a bi-tetrahedral Au8 kernel protected by four Au4(SR)5 motifs.
• Key structural features identified as responsible for fluorescence include interlocked Au4(SR)5 staples and enhanced ligand-to-kernel electron transfer.

Conclusions:

• The study clarifies the structure-fluorescence relationship in Au24(SR)20 nanoclusters.
• Specific structural motifs contribute to reduced vibrational loss and enhanced fluorescence.
• Understanding these relationships can guide the design of novel fluorescent nanomaterials.