The right way to self-fuse bi- and terpyrenyls to afford graphenic cutouts

Abstract

In this work, we subject bi- and terpyrenyls to selective fusion for formation of extended polycyclic aromatic hydrocarbons (PAHs). Connecting the pyrene units at 4-4'- or 1-4'-positions led to smooth formation of extended PAHs, achieved via cyclodehydrogenation. This is far more difficult if pyrene is coupled in the 1,1'-position.

A Dihydrodinaphthoheptacene

“…For example, oxidative cyclodehydrogenation reactions have been successfully investigated by Müllen et al showing their potentials to construct extended polycyclic aromatic hydrocarbons based on the pyrene units. 8 Electrophilic intramolecular cyclization reactions are known for many years as powerful tools to generate spiro carbons [9][10][11][12][13]14 and more generally quaternary carbon bridgeheads. 15 These bridgeheads are of key importance in the structure of organic materials to tune their molecular (eg by electronic effects) or supramolecular (eg by steric effects) properties.…”

Tetrabenzoperipentacene: Stable Five‐Electron Donating Ability and a Discrete Triple‐Layered β‐Graphite Form in the Solid State

“…[6] Clars aromatic sextet rule predicts that the intact peripentacene takes several resonance contributors,s ome of which exhibit radical forms (Scheme 1). [8,9] In contrast to 2,the oxidation of 3 smoothly produced periphery-fused products.T he tetrabenzoperipentacene is considered to be the first conjugated peripentacene,t he skeleton of which is comprises 56 allcarbon atoms. [8] We expected that the strong oxidation of 2 would give the completely planar tetrabenzoperipentacene 4,but instead the stable radical cation 2C + and dication 2 2+ were generated, even under powerful oxidative conditions (Scheme 2).…”

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

“…Obviously, the oxidation strength of FeCl 3 seems not to be sufficient to dehydrogenate this electron‐poor molecule to a π‐extended framework. Another explanation might be that the potential for the formation of new carbon–carbon bonds is significantly reduced at the 4‐, 5‐, 9‐, and 10‐positions of the pyrene radical cations as suggested by Lorbach et al . based on their quantum‐chemical calculations of the spin density distribution in such species.…”