The Mackay-Type Cluster [Cu₄₃ Al₁₂ ](Cp*)₁₂ : Open-Shell 67-Electron Superatom with Emerging Metal-Like Electronic...

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• The synthesis of novel metal clusters with unique electronic and structural properties is a key area in materials science.
• Mackay-type icosahedral structures are of interest due to their unique packing and potential electronic behavior.
• Superatom chemistry explores the electronic shell structure of clusters, analogous to atoms.

Purpose of the Study:

• To synthesize and characterize a novel paramagnetic M55 cluster with a Mackay-type structure.
• To investigate the electronic configuration and magnetic properties of the synthesized cluster.
• To understand the role of all-hydrocarbon ligands in stabilizing reactive metal cores.

Main Methods:

• Reaction of [CuMes]5 and [AlCp*]4 to form the target cluster.
• Structural characterization using techniques suitable for large clusters (e.g., X-ray crystallography, though not explicitly stated, implied by structural description).
• Magnetic susceptibility measurements to determine magnetic properties.

Main Results:

• Successful synthesis of the [Cu43Al12](Cp*)12 paramagnetic cluster.
• The cluster exhibits a Mackay-type nested icosahedral structure.
• An open-shell 67-electron superatom configuration was identified, with three unpaired electrons in jellium states.
• Temperature-independent magnetism was observed, suggesting precursory conduction band formation.
• Steric protection by twelve Cp* ligands was confirmed to suppress polyradicalar reactivity.

Conclusions:

• The synthesized [Cu43Al12](Cp*)12 cluster represents a unique M55 system with a novel electronic configuration.
• The observed magnetic properties support the theoretical prediction of conduction band formation.
• The study highlights the importance of ligand design in stabilizing complex, reactive metal clusters.