Crystal structure of selenolate-protected Au24(SeR)20 nanocluster

Area of Science:

• Nanomaterials Science
• Crystallography
• Inorganic Chemistry

Background:

• Gold nanoclusters are of significant interest due to their unique optical and catalytic properties.
• Understanding the precise atomic structure is crucial for correlating structure with function.
• Selenolate ligands offer an alternative to traditional thiolate ligands in nanocluster synthesis.

Purpose of the Study:

• To determine the X-ray crystal structure of a specific selenolate-capped gold nanocluster, Au24(SeR)20.
• To elucidate the atomic arrangement of the gold kernel and the protecting ligand motifs.
• To compare the structural features with known gold-thiolate nanoclusters.

Main Methods:

• X-ray crystallography was employed to obtain the high-resolution structure.
• Detailed structural analysis was performed on the Au24(SeR)20 nanocluster.
• Comparative analysis with existing gold-thiolate nanocluster structures was conducted.

Main Results:

• The X-ray structure of Au24(SeR)20 (R = C6H5) was successfully determined.
• An unprecedented prolate Au8 kernel, formed by two cross-joined tetrahedral Au4 units, was observed.
• The kernel is stabilized by unique trimeric Au3(SeR)4 and pentameric Au5(SeR)6 staple motifs.

Conclusions:

• The study presents unprecedented structural features for gold-selenolate nanoclusters, including the Au8 kernel and pentameric staple motifs.
• This detailed structural information provides a foundation for understanding the unique properties of gold-selenolate systems.
• The findings highlight the distinct structural characteristics compared to gold-thiolate counterparts.