Charge-dependent hierarchical self-assembling of fluorinated gold nanoclusters

Area of Science:

• Nanomaterials Science
• Supramolecular Chemistry
• Surface Chemistry

Background:

• Gold nanoclusters (NCs) are atomically precise nanomaterials with tunable properties.
• Semifluorinated thiolate ligands (SFLs) offer unique self-assembly characteristics.
• Hierarchical self-assembly of NCs is crucial for advanced material design.

Purpose of the Study:

• To investigate the hierarchical self-assembly of Au25(SR)18 nanoclusters.
• To explore the influence of nanocluster charge state on self-assembly.
• To understand the role of SFLs in directing nanocluster organization.

Main Methods:

• Synthesis of Au25(SR)18 nanoclusters with SFLs.
• Controlled variation of the nanocluster charge state ([Au25]- vs. [Au25]0).
• Characterization of self-assembled structures using electron microscopy and other techniques.

Main Results:

• Anionic [Au25]- NCs decorated with SFLs self-assembled into nanofibers.
• Neutral [Au25]0 NCs decorated with SFLs formed micron-sized filaments.
• The observed structures resulted from the bundling and twisting of nanofibers.

Conclusions:

• The charge state of Au25(SR)18 nanoclusters significantly dictates their hierarchical self-assembly.
• SFLs play a key role in directing the formation of nanofibers and micron-sized filaments.
• This study demonstrates a charge-dependent self-assembly mechanism for functionalized gold nanoclusters.