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Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles
Published on: June 25, 2018
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Understanding Molecular Aggregation of Ligand-Protected Atomically-Precise Metal Nanoclusters
Vikas Tiwari1, Tarak Karmakar1
1Department of Chemistry, Indian Institute of Technology, Delhi, 110016 New Delhi, India.
The Journal of Physical Chemistry Letters
|July 18, 2023
Summary
Monolayer-protected atomically precise nanoclusters (MPCs) aggregate through ligand interactions, forming stable structures. Solvent and ligand charge critically influence this aggregation, offering insights for designing MPC-based applications.
Area of Science:
- Nanomaterials Science
- Computational Chemistry
- Molecular Dynamics
Background:
- Monolayer-protected atomically precise nanoclusters (MPCs) possess unique structures and applications in bioimaging, sensors, and drug delivery.
- Understanding MPC self-assembly dynamics is key for targeted application design.
Purpose of the Study:
- To investigate the atomistic and dynamic details of Au25(pMBA)18 MPC aggregation in aqueous and methanol solutions.
- To elucidate the role of ligand interactions and solvent effects on MPC self-assembly.
Main Methods:
- Molecular dynamics (MD) simulations.
- On-the-fly probability-based enhanced sampling simulations.
- Analysis of dimerization free energy profiles and ligand conformational flexibility.
Main Results:
- MPCs aggregate via hydrogen bonds and π-stacks between aromatic ligands, forming dimers, oligomers, and crystals.
- Ligand charge state and solvent significantly mediate molecular aggregation.
- Ligand conformational flexibility is reduced in the solid phase due to intercluster interactions.
Conclusions:
- Provides detailed molecular-level dynamics of MPC aggregation and ligand conformational changes in solution and crystalline states.
- Highlights the importance of ligand-solvent interactions and ligand charge in controlling MPC self-assembly.
- Offers fundamental insights for the rational design of MPCs for specific applications.
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