Herein we introduce a strategy employing lithium atoms as a scaffold to stabilize an embryo for boron tubes.

An intriguing structural transition from the quasi-planar form of B cluster upon the interaction with lithium atoms is reported. High-level computations show that the lowest energy structures of LiB , Li B , and Li B have quasi-planar (C ), tubular (D ), and cage-like (C ) geometries, respectively. The energetic cost of distorting the B quasi-planar fragment is overcompensated by an enhanced electrostatic interaction between the Li cations and the tubular or cage-like B fragments, which is the main reason of such drastic structural changes, resulting in the smallest tubular (Li B ) and cage-like (Li B ) boron structures reported to date.

After an exhaustive exploration of the potential energy surface of B12E- and B12E2 (E=Li-Cs) systems, it was found that, for the anionic series, a cage-type and a quasi-planar structure, very...

The structure, bonding, and stability of clusters with the empirical formula CE (E=Al-Tl) have been analyzed by means of high-level computations. The results indicate that, whereas aluminum and gallium clusters have C structures with a planar tetracoordinate carbon (ptC), their heavier homologues prefer three-dimensional C forms with a pentacoordinate carbon center over the ptC one. The reason for such a preference is a delicate balance between the interaction energy of the fifth E atom with CE and the distortion energy. Moreover, bonding analysis shows that the ptC systems can be better described as CE , with 17-valence electrons interacting with E. The ptC core in these systems exhibits double aromatic (both σ and π) behavior, but the σ contribution is dominating.

Herein we report the systematic exploration of the potential energy surfaces of a series of clusters with formula E M (E=C-Pb and M=Li-Cs). Fifteen of these combinations adopt a D three-dimensional seven-pointed star-like structure in a singlet state, where M atoms interact electrostatically with the E ring. The determining factors in the relative preference of having the D structure over the most competitive isomer or vice-versa are analyzed. These star-shaped systems satisfy the 4n+2 Hückel's rule and exhibit a strong diatropic (σ and π) response to an external magnetic field.