Beyond organic chemistry: aromaticity in atomic clusters

Area of Science:

• Inorganic Chemistry
• Materials Science
• Quantum Chemistry

Background:

• Aromaticity, a concept from organic chemistry, has been extended to understand bonding in inorganic systems.
• Previous work established aromaticity in MAl4(-) bimetallic clusters and planar boron clusters, analogous to polycyclic aromatic hydrocarbons.
• The need for novel stable cluster structures with unique bonding properties was recognized.

Purpose of the Study:

• To investigate the structures and chemical bonding of novel atomic clusters exhibiting aromaticity.
• To develop a design principle for stable metal-centered aromatic molecular wheels.
• To experimentally and theoretically characterize new borometallic aromatic wheel complexes.

Main Methods:

• Joint experimental and theoretical studies were conducted.
• Supersonic cluster beam techniques were used for production.
• Characterization involved experimental measurements and theoretical calculations.

Main Results:

• Aromaticity was confirmed in various metal cluster systems and planar boron clusters.
• A design principle for M@Bn(k-) metal-centered aromatic molecular wheels was proposed and validated.
• Specific complexes like Ta@B10(-) and Nb@B10(-) were synthesized and characterized, showing high 2D coordination numbers.

Conclusions:

• The concept of aromaticity is a powerful tool for understanding bonding in diverse atomic clusters.
• Stable metal-centered aromatic molecular wheels represent a new class of inorganic aromatic compounds.
• These findings open avenues for designing novel materials with unique electronic and structural properties.