Cage-like B40 (+): a perfect borospherene monocation.

The recent discovery of perfect cage-like D 2d B40 (-) and D 2d B40 (all-boron fullerenes) has led to the emergence of a borospherene family. However, the geometrical and electronic structures of their cationic counterpart B40 (+), previously detected in gas phase, remain unknown to date. Based on extensive first-principles theory calculations, we present herein the possibility of a perfect cage-like D 2d B40 (+) (1) ((2)A1) for the monocation, which turns out to be the global minimum of the system similar to B40 (-) and B40, adding a new member to the borospherene family. Molecular dynamics simulations indicate that D 2d B40 (+) (1) is dynamically stable at 300 K, whereas it starts to fluctuate at 500 K between the two lowest-lying isomers D 2d B40 (+) (1) (W) and C s B40 (+) (3) (M) in concerted W-X-M mechanisms via the transition state of C 1 B40 (+) (X), with forward (W → X → M) and backward (M → X → W) activation energies (Ea) of 14.6 and 6.9 kcal mol(-1), respectively. The spectra from IR, Raman, and UV-vis analyses were simulated to facilitate future characterization of this important borospherene monocation.