Dresden 2020 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 79: Nanostructured Surfaces and Thin Films I: 1D and 2D Networks (joint session O/CPP)

CPP 79.10: Talk

Wednesday, March 18, 2020, 17:15–17:30, WIL B321

Methyl and Vinyl Functional Groups in On-Surface Synthesis — •Marco Di Giovannantonio¹, José I. Urgel¹, Shantanu Mishra¹, Kristjan Eimre¹, Aliaksandr V. Yakutovich¹, Carlo A. Pignedoli¹, Pascal Ruffieux¹, Uliana Beser², Qiang Chen², Zijie Qiu², Akimitsu Narita², Klaus Müllen², and Roman Fasel^1,3 — ¹Empa - Swiss Federal Laboratories for Materials Science and Technology, nanotech@surfaces Laboratory, 8600 Dübendorf, Switzerland — ²Max Planck Institute for Polymer Research, 55128 Mainz, Germany — ³Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland

On-surface synthesis has opened pathways to molecular nanostructures that have been inaccessible so far. Here, we demonstrate the successful use of methyl and vinyl groups to achieve one-dimensional (1D) polymers composed of repeat units with specific ring topologies.

Methyl groups are proven to undergo an oxidative cyclization to the neighboring phenyl, forming five-membered rings and affording unprotected indenofluorene isomers, some of which exhibit high radical character. Vinyl groups enable the formation of additional six-membered rings, affording benzo[k]tetraphene units after a stable intermediate with CH2 groups protruding out of five-membered rings.

The structure and electronic properties of the obtained polymers have been characterized by STM, nc-AFM, and STS, and supported by theoretical calculations. The observed reaction steps and products extend the knowledge of on-surface reactions to fine tune architectures and functionalities.