Stable global tubular boron clusters in Na₂B₁₈ and Na₂B₁₈⁻

Abstract

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.

Exploring the structure and electronic properties of germanium doped boron clusters using density functional theory based global optimization method

“…Tubular structures have also been reported for LiB 20 and LiB 20 − , 55 and Na 2 B 18 and Na 2 B 18 − clusters. 56 The electrostatic interaction between the Li/Na atoms and the boron cluster motif was found to be essential for the stability of these cage-type and tubular structures. Similarly, theoretical calculations revealed that Be, Mg and Al doped boron clusters form planar, quasi-planar and bowl like structures except for MgB 18 and BeB 18 /BeB 20 − which were reported to form tubular drum and cage-type clusters, respectively.…”

Structural transformations in boron clusters induced by metal doping

“…173 Dong et al also found it in B 18 Na 2 and B 18 Na 2 − . 193 They substituted Na with Li and K in the structures obtained from the PES exploration, which yielded the double-ring as the most stable species within this pool of isomers. In this sense, there is a considerable possibility that the GMs of Li 2 B 18 , Li 2 B 18 − , B 18 K 2 , and B 18 K 2 − have the tubular form.…”

“…So, the authors characterized these tubular clusters as “salt complexes”. 193 In addition, the AdNDP approach revealed three types of bonds. Eighteen 2c-2e σ-bonds are forming the two separate B monocycles, along with five 20c-2e σ-bonds and five 20c-2e π-bonds.…”

“…These delocalized bonds account for the strong bonding interactions between each B 9 ring. 193 Note that the rationalization of chemical bonding through the AdNDP analysis is not a black-box approach but instead relies on the chemical intuition of the user. For instance, some authors report the double-ring as a series of localized 2c-2e σ-bonds, as two separate rings, and others as delocalized 3c-2e σ-bonds, representing the triangles forming the two rings.…”

Highly stable actinide(iii) complexes supported by doubly aromatic ligands

“…Among them, metal-doped small-sized boron clusters have been intensively studied, involving alkali, 8,32 alkaline earth, 6,30 and transition metal atom doping. 14,26,29,[33][34][35][36][37][38][39][40] For example, there are Li 2 B 12 , 41 Na 2 B 18 , 42 LiB 20 , 32 MgB n (n = 10-20), 43 17,50 In addition, the number of studies on light actinide(III) complexes reported so far is relatively limited. [51][52][53] If the B 7 3À boron ligand has the ability to stabilize low-valent actinides, it may provide a new way for the synthesis of lowvalent actinide complexes.…”