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Octafunctionalized Biphenylenes: Molecular Precursors for Isomeric Graphene Nanostructures


  • This work is supported by the Transregio SFB TR 49 (Frankfurt, Mainz, Kaiserslautern). We are grateful to Dr. Manfred Wagner for the help with the NMR measurements. We thank Dr. Brenton Hammer for carefully reading the manuscript.


A straightforward method for the octafunctionalization of biphenylene based on the [2+2]-cycloaddition of an aryne intermediate has been developed. This enabled a “North–South” extension of biphenylene towards isomeric graphene nanoribbons composed of four-, six-, and eight-membered rings. This procedure furthermore allowed an “East–West” expansion to [n]phenylenes with different lengths. For the fabrication of isomeric nanongraphenes, octaarylbiphenylenes decorated with phenyl, pyrenyl, and thieno substituents were prepared. The subsequent oxidative cyclodehydrogenation provided an expanded helicene as a model compound.