Spatial and Electronic Structures of BeB8 and MgB8: How far Does the Analogy Go?

• Published in: Chemphyschem 2022-04, Vol.23 (8), p.e202200070-n/a
• Main Authors: Đorđević, Slađana, Radenković, Slavko
• Format: Article
• Language: English
• Subjects: ab initio calculations; Aromaticity; boron clusters; Current density; Electronic structure; Magnesium compounds; Molecular structure; Spatial distribution; Structural stability
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.202200070

Doping boron clusters with Be and its heavier alkaline‐earth congener, Mg, usually leads to complexes of different geometry and electronic structure. In this work we show that both neutral BeB8 and MgB8 exhibit a singlet ground state umbrella‐like form. In addition, the stability, electronic structure, and aromaticity of the target molecules are compared. The magnetically induced current densities show that BeB8 and MgB8 are double aromatic systems: π and σ electrons induce strong diatropic currents. The current densities induced in the studied complexes are of very similar intensity, but with a different spatial distribution. The differences in the current density patterns observed for BeB8 and MgB8 arise from the very nature of the bonding interactions between the M atom and B8 fragment, as demonstrated through the energy decomposition analysis. Magnetic aromaticity: A detailed examination of the potential energy surface for neutral BeB8 and MgB8 in both spin states was performed and global minima are the singlet state umbrella‐like forms. The induced current density in BeB8 and MgB8 is of similar magnitude, but with different spatial distribution.