Valence-delocalized trithorium nanocluster superatoms with open-shell exalted diamagnetism

Area of Science:

• Quantum chemistry
• Materials science
• Nanotechnology

Background:

• Superatoms, clusters mimicking atomic behavior, typically involve main group or transition metals.
• Actinide-actinide bonding is rare, limiting their study in superatom systems.
• The jellium model describes closed-shell nanoclusters, with open-shell variations proposed.

Purpose of the Study:

• To investigate actinide-actinide bonding in nanoclusters.
• To explore the superatom character and electronic properties of thorium nanoclusters.
• To demonstrate actinide open-shell jellium aromaticity.

Main Methods:

• Experimental synthesis and characterization of trithorium nanoclusters.
• Computational analysis including density functional theory (DFT).
• Magnetic susceptibility measurements under applied magnetic fields.

Main Results:

• Discovery of trithorium nanoclusters with three-centre-one-electron actinide-actinide bonding.
• Experimental and computational evidence of Robin-Day Class III 6d-orbital valence delocalization.
• Observation of S=1/2 paramagnetism and exalted diamagnetism in external magnetic fields, confirming superatom aromaticity.

Conclusions:

• Trithorium nanoclusters exhibit unique actinide-actinide bonding and superatom characteristics.
• Valence delocalization in these clusters leads to aromaticity and exalted diamagnetism, defying typical single-electron behavior.
• This work expands the scope of superatom chemistry to actinides, revealing novel electronic properties.