Charging a Negatively Curved Nanographene and Its Covalent Network

Abstract

This study explores a bottom-up approach toward negatively curved carbon allotropes from octabenzo[8]­circulene, a negatively curved nanographene. Stepwise chemical reduction reactions of octabenzo[8]­circulene with alkali metals lead to a unique highly reduced hydrocarbon pentaanion, which is revealed by X-ray crystallography suggesting a local view for the reduction and alkali metal intercalation processes of negatively curved carbon allotropes. Polymerization of the tetrabromo derivative of octabenzo[8]­circulene by the nickel-mediated Yamamoto coupling reaction results in a new type of porous carbon-rich material, which consists of a covalent network of negatively curved nanographenes. It has a specific surface area of 732 m2 g–1 and functions as anode material for lithium ion batteries exhibiting a maximum capacity of 830 mAh·g–1 at a current density of 100 mA·g–1. These results indicate that this covalent network presents the key structural and functional features of negatively curved carbon allotropes.

Redox‐Active Hydrocarbons: Isolation and Structural Determination of Cationic States toward Advanced Response Systems

“…In this review, we focus on examples of succeeding in isolation and structural determination of cationic species based on pure hydrocarbons with aromatic rings and introduce the intrinsic electrochemical and spectroscopic properties of such hydrocarbons. The X‐ray analysis of anionic species consisting of pure hydrocarbons has been achieved only recently [36–44] . Since only a few examples of reversible redox response systems are available, they are not considered in this review.…”

Reversible structural rearrangement of π-expanded cyclooctatetraene upon two-fold reduction with alkali metals

“…Within our research efforts directed toward the development of new types of electron acceptors based on polycyclic aromatic hydrocarbons (PAHs) with nonbenzenoid moieties, 19,20 we have recently reported the chemical reduction of π-expanded COT derivative, octaphenyltetrabenzo-cyclooctatetraene (OPTBCOT, 1 , Scheme 1). Remarkably, reaction of 1 with excess lithium metal afforded a coordinatively stabilized tetraanion instead of the planarized aromatic dianion.…”

Diels–Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry

“…The application possibilities listed above have been discussed in this review. Particular attention is paid to nanographenes, including functionalized and heteroatoms-doped ones, which preparation and new applications constitute a “hot topic” in science and technology [ 6 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. Currently, only bottom-up methods, where nanographene is constructed from smaller entities by stepwise organic synthesis, allow the preparation of nanographenes, including functionalized and doped ones, with perfect control of shapes and sizes and, therefore, perfectly defined properties [ 2 , 5 , 6 , 11 , 12 ,…”

“…It should be added that nanographenes (graphenoids), obtained via reactions discussed in this review, can be planar or otherwise distorted, that is, non-planar, one- (1D), two- (2D), and three-dimensional (3D) [ 6 , 11 , 12 , 17 , 23 , 24 , 25 , 26 , 36 , 38 , 40 , 43 , 46 , 47 , 49 , 52 ]. Graphenoids with planar sheets of varying size, shape, and periphery have made great progress in practical applications of electronics, energy storage, catalysis, and biosensing [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 42 , 44 , 47 , 50 , 52 , 53 ]. In recent years, a growing number of graphenoid studies have focused on unusual curved and warped stru...…”

“…Graphenoids with planar sheets of varying size, shape, and periphery have made great progress in practical applications of electronics, energy storage, catalysis, and biosensing [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 42 , 44 , 47 , 50 , 52 , 53 ]. In recent years, a growing number of graphenoid studies have focused on unusual curved and warped structures such as bowls, helices, and saddles, on account of their structural variation and unique physical and chemical properties [ 6 , 11 , 12 , 14 , 15 , 16 , 17 , 20 , 22 , 23 , 24 , 25 , 26 , 27 , 32 , 33 , 35 ,…”