Pyridinic Nanographenes by Novel Precursor Design

Abstract

In this work we present the solution‐synthesis of pyridine analogues to hexa‐peri‐hexabenzocoronene (HBC)—which might be called superpyridines—via a novel precursor design. The key step in our strategy was the pre‐formation of the C−C bonds between the 3/3’ positions of the pyridine and the adjacent phenyl rings—bonds that are otherwise unreactive and difficult to close under Scholl‐conditions. Apart from the synthesis of the parent compound we show that classical pyridine chemistry, namely oxidation, N‐alkylation and metal‐coordination is applicable to the π‐extended analogue. Furthermore, we present basic physical chemical characterizations of the newly synthesized molecules. With this novel synthetic strategy, we hope to unlock the pyridine chemistry of nanographenes.

Phenanthrene-Extended Phenazine Dication: An Electrochromic Conformational Switch Presenting Dual Reactivity

“… 8 − 12 Moreover, the possibility of introducing the heteroatoms in a neutral state and oxidizing them in a later step can result in materials with a behavior depending on the oxidation state and in molecular switching capabilities due to hybridization change. 13 , 14 While various examples of PAHs presenting a single charged atom in their structure have been reported in different contributions, 2 , 7 , 8 , 15 , 16 doubly charged ones are less explored, with notable examples presenting O, N, S, or combinations of these heteroatoms, using both surface and solution-based chemistry. 17 − 26 From this point of view, parent and π-extended dihydrophenazines represent valuable precursors toward the generation of 2 + N-doped PAHs.…”

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“…The Jux group further reported a solution for synthesis of pyridine analogues of hexa- peri -hexabenzocoronene ( Scheme 5 ). 3 A key feature of their strategy was the early formation of the C–C bonds at the 3 and 5 positions of the pyridine ( 5.1a , b , red bonds). These bonds are otherwise unreactive and difficult to close under oxidative conditions.…”

Novel Synthetic Approach to Heteroatom Doped Polycyclic Aromatic Hydrocarbons: Optimizing the Bottom-Up Approach to Atomically Precise Doped Nanographenes

“…The synthesis of pyridine analogues of HBC (hexa-peri-hexabenzocoronene) 11 , known to be difficult to synthesize, was completed thanks to a novel precursor (compound 10 ) designed with the unreactive 3/3′ position of the pyridine pre-formed ( Scheme 3 ) [ 36 ]. The use of this particularly designed precursor resulted very efficient for the complete closure of the doped HBC using the Scholl reaction.…”