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Polycyclic aromatic hydrocarbons (PAHs) with a one‐dimensional (1D), ribbon‐like structure have the potential to serve as both model compounds for corresponding graphene nanoribbons (GNRs) and as materials for optoelectronics applications. However, synthesizing molecules of this type with extended π‐conjugation presents a significant challenge. In this study, we present a straightforward synthetic method for a series of bis‐peri‐dinaphtho‐rylene molecules, wherein the peri‐positions of perylene, quaterrylene, and hexarylene are fused with naphtho‐units. These molecules were efficiently synthesized primarily through intramolecular or intermolecular radical coupling of in situ generated organic radical species. Their structures were confirmed using X‐ray crystallographic analysis, which also revealed a slightly bent geometry due to the incorporation of a cyclopentadiene ring at the bay regions of the rylene backbones. Bond lengh analysis and theoretical calculations indicate that their electronic structures resemble pyrenacenes more than quinoidal rylenes. That is, the aromatic sextets are predominantly localized along the long axis of the skeletones. As the chain length increases, these molecules exhibit enhanced electronic absorption with a bathochromic shift, and multiple amphoteric redox waves. This study introduces a novel synthetic approach for generating 1D extended PAHs and GNRs, along with their structure‐dependent electronic properties. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) with a one‐dimensional (1D), ribbon‐like structure have the potential to serve as both model compounds for corresponding graphene nanoribbons (GNRs) and as materials for optoelectronics applications. However, synthesizing molecules of this type with extended π‐conjugation presents a significant challenge. In this study, we present a straightforward synthetic method for a series of bis‐peri‐dinaphtho‐rylene molecules, wherein the peri‐positions of perylene, quaterrylene, and hexarylene are fused with naphtho‐units. These molecules were efficiently synthesized primarily through intramolecular or intermolecular radical coupling of in situ generated organic radical species. Their structures were confirmed using X‐ray crystallographic analysis, which also revealed a slightly bent geometry due to the incorporation of a cyclopentadiene ring at the bay regions of the rylene backbones. Bond lengh analysis and theoretical calculations indicate that their electronic structures resemble pyrenacenes more than quinoidal rylenes. That is, the aromatic sextets are predominantly localized along the long axis of the skeletones. As the chain length increases, these molecules exhibit enhanced electronic absorption with a bathochromic shift, and multiple amphoteric redox waves. This study introduces a novel synthetic approach for generating 1D extended PAHs and GNRs, along with their structure‐dependent electronic properties. [ABSTRACT FROM AUTHOR]

A planar dibenzo‐peri‐hexacene derivative (2) was synthesized via FeCl3‐mediated Scholl reaction from a cyclopenta‐fused perylene (CP) based polyphenylene precursor (1). However, an unexpected octagon‐containing, negatively curved molecule (3) was obtained in nearly quantitative yield when 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and methanesulfonic acid (MeSO3H) were used. Similar results were observed when two smaller‐sized precursors containing one (4) or two CP units (5) were tested. X‐ray crystallographic analysis also revealed that there is no close π–π stacking between neighboring π‐conjugated skeletons. DFT calculations suggest a radical cation mechanism in the presence of FeCl3 while an arenium ion pathway for the DDQ/MeSO3H mediated Scholl reaction, which can well explain the selective formation of hexagons and octagons under different conditions. The obtained compounds showed tunable optical and electrochemical properties. [ABSTRACT FROM AUTHOR]

A planar dibenzo‐peri‐hexacene derivative (2) was synthesized via FeCl3‐mediated Scholl reaction from a cyclopenta‐fused perylene (CP) based polyphenylene precursor (1). However, an unexpected octagon‐containing, negatively curved molecule (3) was obtained in nearly quantitative yield when 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and methanesulfonic acid (MeSO3H) were used. Similar results were observed when two smaller‐sized precursors containing one (4) or two CP units (5) were tested. X‐ray crystallographic analysis also revealed that there is no close π–π stacking between neighboring π‐conjugated skeletons. DFT calculations suggest a radical cation mechanism in the presence of FeCl3 while an arenium ion pathway for the DDQ/MeSO3H mediated Scholl reaction, which can well explain the selective formation of hexagons and octagons under different conditions. The obtained compounds showed tunable optical and electrochemical properties. [ABSTRACT FROM AUTHOR]