Ab initio characterization of the flexural anion found in the reversible dehydrogenation

It was recently shown that the B 3 H 8 - anion can be produced during the reversible dehydrogenation of Mg(BH4)2 to Mg(B3H8)2 in the solid under moderate conditions. In this letter we performed a global minimum search for the B 3 H 8 - anion and identified the global minimum structure and one low-lying saddle point structure, which explains the flexural behavior of this anion. Chemical bonding analysis performed by Adaptive Natural Density Partitioning method revealed that the B 3 H 8 - anion is a σ-aromatic species. Calculated VDEs for the global minimum structure can help to interpret future anionic photoelectron spectroscopic study of this anion.