ABSTRACT
Correction for 'Structure and bonding of molecular stirrers with formula B7M2- and B8M2 (M = Zn, Cd, Hg)' by Rui Yu et al., Phys. Chem. Chem. Phys., 2020, 22, 12312-12320, https://doi.org/10.1039/D0CP01603A.
ABSTRACT
In this work, we systematically explored clusters with formula B7M2- and B8M2 (M = Zn, Cd, Hg). The putative global minima are formed by an M2 dimer and a disk-shaped boron wheel. Moreover, the chemical bonding analysis revealed that charge transfer from the metal atoms to the boron motifs resulted in (B7)3-(M2)2+ and (B8)2-(M2)2+ complexes with double (σ + π) aromatic boron wheels and a single bond for the metallic dimer. Above all, the computed rotational barriers of the M-M fragment with respect to the boron disk and molecular dynamics simulations indicate a virtually barrierless spin, resembling a magnetic stirrer on a baseplate.
ABSTRACT
The putative global minimum of clusters with formula B10M2 (M = Rh, Ir) corresponds to icosahedral structures formed by two alternately stacked B5 rings with the metals located at the top and bottom vertices. These structures are the closest approximation of molecular clusters to the elusive icosahedral boron. A detailed analysis of the chemical bonding revealed that the covalent character between the transition metal and the boron framework as well as the strong delocalization throughout the structure enhances the stabilization of the icosahedral form.
ABSTRACT
Herein we introduce a strategy employing lithium atoms as a scaffold to stabilize an embryo for boron tubes. The systematical exploration of the potential energy surface via evolutionary algorithms allowed us to find that Li2B24 adopts a tubular structure formed by three stacked rings of eight borons each with two lithium atoms capping the tube. The lithium atoms are essential for stabilization because of the strong electrostatic interaction between the Li cations and the boron framework, and concomitantly, they compensate for the energy cost of distorting a quasi-planar or double ring B24 cluster.
ABSTRACT
The electron deficiency and strong bonding capacity of boron have created numerous species with unusual structural and electronic properties in the form of pure and hetero-atom doped boron clusters. Here we identified D 9d-symmetry Na2B18 and Na2B18 - tubular boron clusters as global minima, whose stability is significantly enhanced by two doped sodium atoms. The doped Na atoms trigger strong charge transfer from Na to the boron motifs, resulting in salt complexes (Na2 2+B18 2- and Na2 2+B18 3-). In particular, the optimal electrostatic interactions arising from the doping effect play a crucial role in stabilizing the tubular structure against the planar and quasi-planar preferences of the negatively charged boron clusters.
ABSTRACT
We present a strategy by which the stability of tubular boron clusters can be significantly enhanced by doping the B20 cluster with a lithium atom. High-level quantum chemical calculations showed that the lowest energy structures of LiB20 and LiB20- are tubular structures with D10d symmetry, in which the lithium atom is located at the center of the tubular structure. Chemical bonding analysis revealed that the high-symmetry tubular boron clusters are characterized as charge transfer complexes (Li+B20- and Li+B202-), resulting in double aromaticity with delocalized π + σ bonding and strong electrostatic interactions between cationic Li+ and tubular boron motifs with twenty Li-B interactions. The unique bonding pattern of the LiB20 and LiB20- species provides a key driving force to stabilize tubular structures over quasi-planar structures, suggesting that electrostatic interactions resulting from alkali metals might unveil a new clue to the structural evolution of boron clusters.
ABSTRACT
An intriguing structural transition from the quasi-planar form of B12 cluster upon the interaction with lithium atoms is reported. High-level computations show that the lowest energy structures of LiB12 , Li2 B12 , and Li3 B12 have quasi-planar (Cs ), tubular (D6d ), and cage-like (Cs ) geometries, respectively. The energetic cost of distorting the B12 quasi-planar fragment is overcompensated by an enhanced electrostatic interaction between the Li cations and the tubular or cage-like B12 fragments, which is the main reason of such drastic structural changes, resulting in the smallest tubular (Li2 B12 ) and cage-like (Li3 B12 ) boron structures reported to date.
