A grossly warped nanographene and the consequences of multiple odd-membered-ring defects

Abstract

Graphite, the most stable form of elemental carbon, consists of pure carbon sheets stacked upon one another like reams of paper. Individual sheets, known as graphene, prefer planar geometries as a consequence of the hexagonal honeycomb-like arrangements of trigonal carbon atoms that comprise their two-dimensional networks. Defects in the form of non-hexagonal rings in such networks cause distortions away from planarity. Herein we report an extreme example of this phenomenon. A 26-ring C80H30 nanographene that incorporates five seven-membered rings and one five-membered ring embedded in a hexagonal lattice was synthesized by stepwise chemical methods, isolated, purified and fully characterized spectroscopically. Its grossly warped structure was revealed by single-crystal X-ray crystallography. An independent synthetic route to a freely soluble derivative of this new type of 'nanocarbon' is also reported. Experimental data reveal how the properties of such a large graphene subunit are affected by multiple odd-membered-ring defects.

An Electron‐Poor C64 Nanographene by Palladium‐Catalyzed Cascade C−C Bond Formation: One‐Pot Synthesis and Single‐Crystal Structure Analysis

“…98 Å 2 ) 21. In contrast, all nanographenes with an even higher carbon content of C 80 5c or C 96 14 that have been reported thus far showed strongly distorted π‐scaffolds owing to the incorporation of odd‐membered rings or steric constraints at the edges of the disc‐shaped molecules. …”

Many‐body effects in optical response of graphene‐based structures

“…[62] One of the goals of that article was to interpret the spectrum measured for grossly warped nanographene C 80 H 30 . [63] This structure was modeled by a fragment containing a pentagonal ring at the center and five heptagonal rings (inset in Fig. 7).…”

Synthesis of Five‐Porphyrin Nanorings by Using Ferrocene and Corannulene Templates

“…The ferrocene‐based template T5 Fc was synthesized by phosphine‐activated palladium‐catalyzed aryl–aryl coupling,10 while T5   cor was synthesized from corannulene by iridium‐catalyzed borylation,3a, 11 followed by Suzuki coupling. Both templates are effective in directing the palladium‐catalyzed oxidative coupling of porphyrin monomer P1 to give the five‐porphyrin nanoring in yields of 4.0 % for c ‐P5⋅T5 Fc and 6.1 % for c ‐P5⋅T5   cor (Scheme 2).…”