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Updated: Jun 8, 2026

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Published on: February 5, 2016

Bond length contraction in gold nanoparticles.

Wojciech Szczerba¹, Heinrich Riesemeier, Andreas F Thünemann

¹BAM Federal Institute for Materials Research and Testing, Richard-Willstaetter-Strasse 11, 12489 Berlin, Germany.

Analytical and Bioanalytical Chemistry

|September 18, 2010

Summary

Gold nanoparticle size affects atomic structure, with smaller particles showing greater bond length contraction in solution. This differs from surface-immobilized nanoparticles, impacting catalysis understanding.

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Area of Science:

Materials Science
Nanotechnology
Physical Chemistry

Background:

Nanoparticle structure often deviates from bulk materials.
Gold nanoparticles exhibit high catalytic activity, prompting structural investigations.
Understanding gold nanoparticle structure is crucial for catalysis.

Purpose of the Study:

To investigate the relationship between size and Au-Au bond length in gold nanoparticles.
To compare the structural properties of gold nanoparticles in solution versus on surfaces.
To elucidate the impact of structural differences on catalytic activity.

Main Methods:

In situ extended X-ray absorption fine structure (EXAFS) spectroscopy to determine bond lengths.
Small-angle X-ray scattering (SAXS) for particle size and distribution analysis.
Ab initio calculations to analyze EXAFS spectra.

Main Results:

A size-dependent Au-Au bond length contraction was observed in aqueous gold nanoparticles.
Nanoparticles with a 2.9 nm radius showed a 2 pm contraction; 4.4 nm particles showed a 1 pm contraction.
Larger, 25.7 nm particles exhibited bulk-like Au-Au distances (288 pm).

Conclusions:

The bond length contraction in solution-phase gold nanoparticles is significantly smaller than in surface-immobilized ones.
This difference highlights distinct structural behaviors between free and supported nanoparticles.
Findings are essential for understanding nanoparticle-supported catalysis mechanisms.