Neither Too Classic nor Too Exotic: One-Electron Na⋅B Bond in Nabh3− Cluster

It is here reported that the NaBH3− cluster exhibits a Na⋅B one-electron bond, a well-established type of electron-deficient bonding in the literature. The topological analysis of the electron localization function, at the correlated level, reveals that Na−, when approaching the bonding distance, fairly distributes its valence electron pair between two lobes. One of these electrons is used to bond with BH3, which participates through its boron empty p-orbital. Furthermore, the bonding situation of LiBH3−, KBH3−, MgBH3, and CaBH3 global minima structures are similar to that of NaBH3−, extending the family of these new one-electron bond systems with biradicaloid character. © 2021 Wiley-VCH GmbH