C20-related structures: Diamond D5

A tetrahedral array of C20 fullerene molecules, when fused together, form a five-membered ring multi-cage, named C57. The stability and aromaticity of C57 and related hydrogenated structures was computationally evaluated by using Hartree-Fock (HF/6-31G(d,p)) and density functional theory (B3LYP/6-31G(d,p)). A possible synthetic route to C57, starting from a tetrahedral carbon atom, by appropriately adding of C1 or C2 units, in a manner similar to the dendrimer divergent synthesis, is proposed. A variety of all-pentagon ring multi-cage structures (both opened and closed ones) were thus derived and their stability evaluated. Finally, a triple periodic network, called the diamond D5, consisting of alternating chirally-bonded C57 units, is designed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Model study of five-membered ring carbon multi-cage. ► Synthetic route to an all pentagonal carbon network, diamond D5. ► Aromaticity of C57 and reduced multi-cage species.