A molecular bowl sumanene

Abstract

Nonplanar polyaromatic carbon molecules including fullerenes and carbon nanotubes have been attracting great interest due to their potential as materials, catalysts, etc. In this context, bowl-shaped polyaromatic hydrocarbons (π bowls) are considered to be key materials in the science of nonplanar π-conjugated carbon systems. Among π bowls, we focused on a molecular bowl "sumanene (C(21)H(12))" featuring a C(3v) symmetric structural motif present in fullerenes or carbon nanotube molecules. In this article, we present the research on sumanenes to date, including their synthesis, structural characterization, derivatization, complexation, and their potential uses as electrical materials. The characteristic structural feature of a sumanene depends on three sp(3) hybridized carbon atoms at the benzylic positions. Facile functionalization via selective formation of benzylic anions gives stereoselective substituted compounds, the π-extended derivatives, and the deeper π bowls. Furthermore, the dynamically flexible aspect based on bowl-to-bowl inversion is also described. The crystal with a columnar bowl-in-bowl stacking exhibits a high electron transport ability with anisotropy. Complexation with a cyclopentadienyl iron cation results in the first selective formation of the concave-bound complex as a π-bowl complex.

Enantioselective synthesis of a chiral nitrogen-doped buckybowl

“…Buckybowls have attracted much attention not only as model compounds for fullerenes, but also for their own chemical and physical properties [10][11][12][13] . In contrast to nitrogen-doped fullerenes and CNTs, nitrogen-doped buckybowls, azabuckybowls, still remain unknown except for some theoretical studies 14,15 .…”

Synthesis, Structures, and Physical Properties of Aromatic Molecular-Bowl Hydrocarbons

“…The chemistry of corannulene-based [4][5][6][7][8][9][10][11][12] and sumanene-based buckybowls [4,[12][13][14][15] has been described in several review articles. In 2006 we published a review article focusing on the solution-phase synthesis of buckybowls, and the structures and physical properties of compounds thus prepared [7].…”

Chiral Buckybowl Molecules

“…The conjugated bowl structure itself possesses the chirality, such as π-extended buckybowls, e.g., hemifullerene 3; bowl chirality caused by introduction of one or more substituents on the rim of the buckybowl, e.g., trimethylsumanene 4; and bowl chirality originated from the introduction of heteroatom into the π-bowl carbon skeleton, e.g., triazasumanene 5. While several buckybowl-related reviews have been published in recent years [6,[39][40][41][42][43][44], most of them focused on the synthetic strategy and derivation method. Only a few publications involve the stereochemistry or chirality of the buckybowls.…”

“…A better understanding of bowl chirality will help researchers find a good way to control the chiral self-assembly of carbon nanotubes (CNTs) or fullerenes, which have already exhibited exciting potential as next-generation functional materials [28][29][30][31][32][33][34][35][36][37][38]. While several buckybowl-related reviews have been published in recent years [6,[39][40][41][42][43][44], most of them focused on the synthetic strategy and derivation method. Only a few publications involve the stereochemistry or chirality of the buckybowls.…”