Superatomic or Not? A Case Study on Isostructural Au₃Ag₂ and Au₃Cu₂ Nanoclusters

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Bimetal nanoclusters offer tunable properties for advanced applications.
• Understanding the impact of specific atom doping is crucial for designing novel nanoclusters.

Purpose of the Study:

• To synthesize and characterize two novel bimetal nanoclusters: [Au3Ag2(Ppy3)6](NO3)3 (Au3Ag2) and [Au3Cu2(Ppy3)6](BF4)3 (Au3Cu2).
• To investigate the structural, electronic, and stability differences between Au3Ag2 and Au3Cu2 nanoclusters.
• To explore the influence of atom doping on superatomic properties.

Main Methods:

• Synthesis of bimetal nanoclusters using tri(2-pyridyl)phosphine (Ppy3).
• Single crystal X-ray structural analysis to determine molecular geometry.
• Theoretical calculations to probe electronic structures and superatomic characteristics.

Main Results:

• Both nanoclusters exhibit trigonal bipyramidal structures with distinct atomic arrangements.
• Au3Ag2 demonstrates superior stability in solution compared to Au3Cu2.
• Theoretical analysis identifies Au3Ag2 as a well-defined superatom, while Au3Cu2 is nonsuperatomic despite similar electron counts.

Conclusions:

• Atom doping plays a critical role in modulating the electronic structure and superatomic behavior of metal nanoclusters.
• The choice of dopant atom significantly impacts nanocluster stability and electronic properties.
• This research provides insights into the design principles for creating functional superatomic metal nanoclusters.