Abstract
AbstractPolyphenylenes (PPs) are unique polymers showing high mechanical strength and chemical stability, and having potential applications, for example, in proton transfer and gas‐separation membranes. Moreover, phenyl‐substituted linear PPs can serve as precursors for bottom‐up syntheses of graphene nanoribbons (GNRs), a new class of nanoscale carbon materials that appear promising for nanoelectronics. Notably, lateral extensions of linear PPs with appropriate “branched” phenyl substituents, that is, avoiding spatial overlap of benzene rings in their projections into a plane, can lead to wider GNRs with modulated electronic and optical properties. GNRs with widths up to ≈2 nm are obtained, but synthetic methods to further expand PPs laterally so as to achieve even wider GNRs have not yet been developed. Here, phenyl‐substituted linear PPs bearing two ethynyl groups at “outer” positions in each repeating unit, together with 3,4‐diphenylcyclopentadienones bearing a trimethylsilyl‐protected ethynyl group are used for stepwise lateral extension of the PPs, based on a sequence of Diels–Alder cycloadditions and deprotections. Each successive reaction step is corroborated by 1H NMR and IR spectroscopy, as well as gel permeation chromatography, providing a new pathway toward branched polyphenylenes with linear‐PP‐backbones that can potentially serve as precursors of wider GNRs with tunable electronic bandgaps.
Highlights
Polyphenylenes (PPs) are unique polymers showing high mechanical strength PPs with phenyl substituents can and chemical stability, and having potential applications, for example, in proton transfer and gas-separation membranes
One of the most efficient methods to synthesize PPs is through the use of Diels–Alder cycloadditions between cyclopentadienone (CP) derivatives, usutroscopy, as well as gel permeation chromatography, providing a new pathway ally 2,3,4,5-tetraarylcyclopentadienones, toward branched polyphenylenes with linear-PP-backbones that can potentially serve as precursors of wider graphene nanoribbons (GNRs) with tunable electronic bandgaps
We have developed an elegant method for lateral expansion of a linear PP by reaction with diphenyl-CP derivatives using a stepwise Diels–Alder cycloaddition/deprotection protocol
Summary
Polyphenylenes (PPs) are unique polymers showing high mechanical strength PPs with phenyl substituents can and chemical stability, and having potential applications, for example, in proton transfer and gas-separation membranes. One of the most efficient methods to synthesize PPs is through the use of Diels–Alder cycloadditions between cyclopentadienone (CP) derivatives, usutroscopy, as well as gel permeation chromatography, providing a new pathway ally 2,3,4,5-tetraarylcyclopentadienones, toward branched polyphenylenes with linear-PP-backbones that can potentially serve as precursors of wider GNRs with tunable electronic bandgaps. Polyphenylenes (PPs) are polymers with exceptional properties,[1,2] including outstanding mechanical strength as well as thermal and chemical stability This qualifies them for applications under harsh conditions, such as proton transfer,[3,4,5,6,7] electrodialysis,[8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
