Li₈Si₈, Li₁₀Si₉, and Li₁₂Si₁₀: Assemblies of Lithium‐Silicon Aromatic Units

Abstract

We report the global minima structures of Li8Si8, Li10Si9, and Li12Si10 systems, in which silicon moieties maintain structural and chemical bonding characteristics similar to those of their building blocks: the aromatic clusters Td−Li4Si4 and C2v−Li6Si5. Electron counting rules, chemical bonding analysis, and magnetic response properties verify the silicon unit‘s aromaticity persistence. This study demonstrates the feasibility of assembling silicon‐based nanostructures from aromatics clusters as building blocks.

Si5-pentagonal rings and Y-shaped Si4building blocks in Li32Si18system: similarities with the crystalline Zintl phase Li12Si7

“…4 shows the results of the AdNDP analysis. In the case of Li 6 Si 5 , we obtain a similar representation to the one previously reported, 52 five lone pairs, one on each Si, five Si–Si σ-bonds plus three delocalized π-bonds connecting the Si 5 ring, the latter consistent with the aromatic character of this cluster. 49,93,94 For the case of Li 10 Si 4 , AdNDP recovers six lone pairs (two on each of the three external silicon).…”

“…Thus, for example, our group recently demonstrated that the global minima T d -Li 4 Si 4 and C 2v -Li 6 Si 5 consisting of Zintl Si 4 4− (tetrahedron) and Si 5 6− (pentagon) anions maintain their silicon motifs, almost unchanged, in the Li 8 Si 8 , Li 10 Si 9 , and Li 12 Si 10 combinations. 51,52 Furthermore, Li 6 Si 5 can be stacked to form a nanowire within a carbon nanotube. 53 These findings suggest that these small clusters could work as assembly blocks for CAMs, which is particularly interesting because these structural patterns have been identified in Li–Si materials.…”