From inverse sandwich Ta₂B₇⁺ and Ta₂B₈ to spherical trihedral Ta₃B₁₂⁻: prediction of the smallest metallo-borospherene

Abstract

Structural transition from inverse sandwich Ta2B7+ (1) and Ta2B8 (2) with σ + π dual aromaticity to the smallest metallo-borospherene D3h Ta3B12− (3) which is σ + π + δ triply aromatic in nature.

Cage-like La4B24 and Core-Shell La4B290/+/− : perfect spherically aromatic tetrahedral metallo-borospherenes

“…We also reported the smallest metallo-borospherene D 3h Ta 3 B 12 − composed of two eclipsed B 3 triangles on the top and bottom interconnected by three B 2 units on the waist [27]. However, to the best of our knowledge, there have been no experimental or theoretical evidence reported on tetra-La-doped boron clusters to date.…”

TM4B180/− (TM = Hf, Ta, W, Re, Os): new structure construction with TM doped B wheel units

“…The previous studies proved the feasibility of the PBE0 functional 45 to describe the energy differences between different isomers of TM doped B clusters. 35,37,39,[46][47][48] Moreover, our previous study of the single TM atom doped B n (n ¼ 7-10) clusters 49 also conrmed that PBE0 functional can precisely describe the interactions between TM atom and B atom by comparing with the high-level CCSD(T) 50 results. For basis set, the 6-311G* was proved enough to describe B atom in our study of pure boron clusters.…”

“…(i) planar molecular wheel, [21][22][23] (ii) half-sandwich, 24 inverse sandwich 25,26 and inverse triple-decker 27 clusters, (iii) drum-like structures, [28][29][30] (iv) the endohedral boron cages, [31][32][33][34] and (v) metallo-borospherenes. [35][36][37][38] Doping single TM atom into small-sized B clusters produces perfect TM-centered monocyclic B wheel clusters such as Co@B 8 À , 21 Rh@B 9 À , 22 and Ta@B 10 À . 23 The 10 coordination number (CN) of Ta@B 10 À is known as the highest number among the planar species.…”

“…units on the waist,37 the lowest energy structures of Hf 4 B 18 and Ta 4 B 18 possess a large E HL of 2.60 and 2.61 eV, respectively, being less chemically reactive than others. For all anionic clusters, due to the trapping of an electron, the E HL of these species is decreased and signicantly less than the neutral clusters.…”

Perfect Spherical Tetrahedral Metallo-Borospherene Ta4B18 as a Superatom Following the 18-Electron Rule

“… 32 The smallest tri-Ta-doped spherical trihedral metallo-borospherene D 3h Ta 3 B 12 – ( 1 ) has been very recently predicted by our group, which consists of two eclipsed B 3 triangles on the top and bottom interconnected by three B 2 units on the waist. 33 However, there have been no experimental or theoretical evidence reported on tetra-Ta-doped boron clusters to date. Tetra-metal-doped endohedral metallo-silicon fullerenes T d M 4 Si 28 (M = Al and Ga) have been theoretically proposed to possess the same tetrahedral symmetry as their fullerene counterpart T d C 28 .…”