Linear vs Star-Shaped Be5O62- Cluster Arrays. Balance Between Repulsion and Electronic Stabilizing Terms

Abstract

The identification of the most favorable isomers is crucial for understanding non-classical clusters. For Be 5O 6 2− cluster, a recently reported structure ascribes the most favorable isomer as a star-shaped cyclic D 5h-Be 5O 6 2−, contrasting to the previously claimed linear isomer. Our results reveal the key factors that determine the most favorable isomer, which are facilitated by an increase in orbital and electrostatic stabilizing terms that overcome the increase in steric repulsion, resulting in a more compact structure. Computationally evaluated 17O-NMR and aromatic characteristics, reveals a non-aromatic behavior. The current approach is useful for further understanding the preference between isomers in non-classical clusters.