Theoretical probing of twenty-coordinate actinide-centered boron molecular drums

Geometric and electronic structures of medium-sized boron clusters doped with plutonium

Doping metal heteroatoms is an effective strategy to regulate the geometric and electronic structure of boron based nanoclusters. However, the exploration of the ground state structures of metal-boron-based nanoclusters is still a challenge duo to the complexity of the bonding interactions between heterogeneous atoms and boron cluster and the number of isomers on the potential energy surface increases exponentially with cluster size. Here, we use the CALYPSO cluster structural search method in combination with density functional theory calculations to study the geometries and electronic properties of anionic boron clusters doped with plutonium (PuBn-,n= 10-20). Our results show that the medium-sized PuB14-cluster exhibits excellent stability with highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap of 2.30 eV. The remarkable stability of the anionic PuB14-cluster is due to the robust interactions between the Pu metal and the B14skeleton, along with the strong covalent interactions between the B atoms. These findings enrich the geometric structure database of metal doped clusters and provide valuable insights for the future synthesis of boron based nanomaterials.

Quasi-planar Co atom-doped boron cluster: CoB192

PURPOSE AND METHODS

A global search for the lowest energy structure of CoB₁₉^2- clusters was conducted.  RESULTS: Its ground state is a quasi-planar structure with the Co atom surrounded by a B₈ ring. The central Co atom has an oxidation state of +1 with d⁸ electron configuration. The wave function analysis showed that the Co-B interaction is not a covalent bond. The bonding strength of peripheral B-B bonds is stronger than that of inner ones. The inner B₈ ring bonds with outer boron atoms via σ- and π-type bonds.

CONCLUSION

CoB₁₉^2- shows remarkable aromatic character.

Construction of the Largest Metal-Centered Double-Ring Tubular Boron Clusters Based on Actinide Metal Doping

Metal doping has been considered to be an effective approach to stabilize various boron clusters. In this work, we constructed a series of largest metal-centered double-ring tubular boron clusters An@B₂₄ (An = Th, Pa, Pu, and Am). Extensive global minimum structural searches combined with density functional theory predicted that the global minima of An@B₂₄ (An = Th, Pu, and Am) are double-ring tubular structures. Formation energy analysis indicates that these boron clusters are highly stable, especially for Th@B₂₄ and Pa@B₂₄. Detailed bonding analysis shows that the significant stability of An@B₂₄ is determined by the covalent character of the An-B bonding, which stems from the interactions of An 5f and 6d orbitals and B 2p orbitals. These results show that actinide metal doping is a feasible route to construct stable large metal-centered double-ring tubular boron clusters, offering the possibility to design boron nanomaterials with special physiochemical properties.