Isomeric Ag₁₄ Nanoclusters With Distinct Photophysical and Nanomechanical Properties

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Atomically precise nanoclusters (NCs) are functional nanomaterials.
• Positional isomerism in NCs, arising from ligand shells, influences their properties.

Purpose of the Study:

• Synthesize and characterize two neutral isomeric [Ag14(CBDT)6(TPP)4] nanoclusters.
• Investigate the impact of ligand coordination on NC structure, luminescence, and mechanical properties.

Main Methods:

• Synthesis of Ag14 isomeric nanoclusters using ortho-carborane-9,12-dithiol and triphenylphosphine.
• Density Functional Theory (DFT) calculations to analyze electronic structure.
• Photoluminescence (PL) spectroscopy to study emission properties.
• Nanoindentation to assess mechanical characteristics.

Main Results:

• Two distinct Ag14 isomers, Ag14T and Ag14S, were synthesized based on triphenylphosphine (TPP) ligand positioning.
• Ag14S exhibits a narrowed HOMO-LUMO gap compared to Ag14T.
• Ag14T shows green phosphorescence, while Ag14S displays red phosphorescence at room temperature.
• Ag14S demonstrates slightly higher stiffness and hardness.

Conclusions:

• Phosphine ligand binding is a versatile strategy for tuning the structure, luminescence, and mechanical properties of atomically precise NCs.
• These tailored NCs hold promise for applications in optoelectronics and nanomechanics.