Negatively curved molecular nanocarbons containing multiple heptagons are enabled by the Scholl reactions of macrocyclic precursors

Molecular Carbons: How Far Can We Go?

“…Very recently, Miao et al also reported the synthesis of negatively curved molecular nanocarbons containing multiple heptagons. 168 These target molecules synthesized from macrocyclic precursors by Scholl reactions not only are the fragments of carbon Schwarzites but also give perception to periodic 3D molecular carbons with intriguing properties. An exploration of three-dimensional carbon nanomaterials from negatively curved molecular carbon has been reported by Miao, Li, and Petrukhina et al in 2021.…”

“…This discovery suggested a supramolecular 2D material if a crystalline monolayer of 145b could be obtained. Very recently, Miao et al also reported the synthesis of negatively curved molecular nanocarbons containing multiple heptagons . These target molecules synthesized from macrocyclic precursors by Scholl reactions not only are the fragments of carbon Schwarzites but also give perception to periodic 3D molecular carbons with intriguing properties.…”

Highly Contorted Rigid Nitrogen-Rich Nanographene with Four Heptagons

“…19 The calculated energy barrier of nonethylated DPA (19.4 kcal/mol) going through a saddle-shaped transition state is more than three times higher than that of OPN (5.9 kcal/mol). Notably, [7]circulene and [7.7]circulene fully surrounded with hexagons have lower inversion energy barriers (9 and 11 kcal/mol respectively) because of continuous wave-like pseudorotation. 1c Such pseudorotation is not available to DPA because the seven-membered rings are only surrounded by six rings, making it more rigid.…”

“…Yamamoto's seminal work on [7.7]circulene 6 paved the way for the development of carbon-based NGs with three adjacent heptagons by Miao's group in 2023. 7 Additionally, Gryko and colleagues have recently achieved the synthesis of nitrogendoped NGs with multiple odd-membered rings. 8 Despite their potential, NGs with multiple heptagonal rings often suffer from lengthy synthetic routes.…”

Synthesis, Structure, and Properties of a Nitrogen–Boron–Nitrogen-Embedded Polycyclic π-System Containing a Pleiaheptalene Framework

“…Despite the significant advancement of synthetic strategies, PAHs with multiple fused heptagons are still relatively underexplored. Limited examples include nanocarbons with three linear-fused heptagons as developed by Miao et al and molecules containing four continuous heptagons synthesized by Liu et al (Figure a). On the other hand, the insertion of heteroatoms into PAHs sometimes enables the synthesis of molecular skeletons that otherwise are inaccessible .…”