Gold doping of tin clusters: exo- vs. endohedral complexes

Area of Science:

• Physical Chemistry
• Materials Science
• Nanotechnology

Background:

• Understanding the structure and properties of doped metal clusters is crucial for developing new materials.
• Gold-doped tin clusters (Sn_NAu) represent a novel class of nanostructures with potential applications.

Purpose of the Study:

• To investigate the structural and electronic properties of neutral gold-doped tin clusters (Sn_NAu, N = 6-16).
• To determine the minimum number of tin atoms required to encapsulate a gold atom.
• To explore the role of spin-orbit effects and charge transfer in these systems.

Main Methods:

• Molecular beam electric deflection experiments were used to probe neutral cluster beam profiles.
• Classical trajectory simulations were employed to interpret experimental data.
• Genetic algorithms based on density functional theory (DFT) generated candidate cluster structures.
• Two-component DFT calculations assessed the importance of spin-orbit interactions.

Main Results:

• A minimum of nine tin atoms (N ≥ 9) are required to form a stable cage structure capable of encapsulating a gold atom.
• The gold atom causes only minor distortions to the high-symmetry tin cage.
• Spin-orbit effects are significant for describing certain gold-doped tin cluster configurations.
• Partial charge analysis indicates charge transfer from the tin host to the gold dopant, resulting in a negatively charged gold atom.

Conclusions:

• The study elucidates the structural requirements for gold encapsulation in tin clusters.
• Electronic structure calculations highlight the necessity of considering relativistic effects and charge transfer for accurate modeling.
• These findings provide fundamental insights into the chemistry of doped metal nanoclusters.