Lithium doped tubular structure in LiB₂₀ and LiB₂₀^-: a viable global minimum

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Materials Science

Background:

• Boron clusters are known for their diverse structures, often exhibiting unique electronic properties.
• Stabilizing specific cluster geometries, like tubular forms, is crucial for potential applications.

Purpose of the Study:

• To investigate the effect of lithium doping on the stability of B20 boron clusters.
• To elucidate the bonding mechanisms responsible for stabilizing tubular structures.

Main Methods:

• High-level quantum chemical calculations were employed to determine the lowest energy structures.
• Chemical bonding analysis was performed to understand the nature of interactions within the doped clusters.

Main Results:

• Lithium-doped B20 clusters (LiB20 and LiB20-) adopt stable tubular structures with D10d symmetry.
• These structures are characterized as charge transfer complexes (Li+B20- and Li+B202-) with double aromaticity (π + σ bonding).
• Strong electrostatic interactions between Li+ and the boron framework, along with numerous Li-B bonds, stabilize the tubular form.

Conclusions:

• Lithium doping significantly enhances the stability of tubular boron clusters.
• Electrostatic interactions driven by alkali metal doping offer a new pathway for controlling boron cluster structures.
• This finding may provide insights into the broader structural evolution of boron clusters.