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Optical properties of metal-ion-mediated Au25 nanocluster-based assemblies
Hanna Jääskö1, Sami Malola1, Hannu Häkkinen1,2
1Department of Physics, Nanoscience Center, University of Jyväskylä, Jyväskylä 40014, Finland. hannu.j.hakkinen@jyu.fi.
Physical Chemistry Chemical Physics : PCCP
|April 24, 2026
Summary
Superatomic gold nanocluster assemblies exhibit tunable optical properties and surprising chiroptical responses. Metal ion coordination induces chirality, offering new avenues for chiral materials and spin conductivity control.
Area of Science:
- Materials Science
- Nanotechnology
- Computational Chemistry
Background:
- Superatomic building blocks, analogous to atoms, form cluster assemblies with unique optical properties.
- Gold nanocluster assemblies mediated by various metal ions have recently emerged.
Purpose of the Study:
- To investigate the optical properties of metal ion-mediated gold nanocluster assemblies.
- To explore the origin of chiroptical response in these assemblies using theoretical calculations.
Main Methods:
- Time-dependent density functional theory (TD-DFT) calculations were employed.
- Optical absorption spectra were simulated for different metal ion coordination.
Main Results:
- Metal ion coordination significantly altered absorption spectra, causing redshifts up to 51 nm.
- Achiral gold nanocluster assemblies unexpectedly displayed chiroptical activity.
- Chirality originates from metal-ligand coordination complexes and transfers to the nanoclusters.
Conclusions:
- Metal ions play a crucial role in tuning the optical properties of gold nanocluster assemblies.
- The emergence of chirality in achiral assemblies presents a novel mechanism for inducing optical activity.
- These findings pave the way for designing enantiopure nanocluster assemblies with chirality-controlled spin conductivity.
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