Static Scanning Tunneling Microscopy Images Reveal the Mechanism of Supramolecular Polymerization of an Oligopyridine on Graphite

Felix D Goll; Gerhard Taubmann; Ulrich Ziener

doi:10.1002/anie.202117580

Static Scanning Tunneling Microscopy Images Reveal the Mechanism of Supramolecular Polymerization of an Oligopyridine on Graphite

Angew Chem Int Ed Engl. 2022 Apr 11;61(16):e202117580. doi: 10.1002/anie.202117580. Epub 2022 Feb 21.

Authors

Felix D Goll¹, Gerhard Taubmann², Ulrich Ziener¹

Affiliations

¹ Ulm University, Institute of Organic Chemistry III, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
² Ulm University, Institute of Theoretical Chemistry, Albert-Einstein-Allee 11, 89081, Ulm, Germany.

Abstract

Supramolecular polymerization of a donor-acceptor bisterpyridine (BTP) equipped with an electron-rich carbazole unit is observed by scanning tunneling microscopy (STM) at the highly oriented pyrolytic graphite (HOPG)|solution interface. It is shown that two-dimensional crystals of supramolecular (co)polymers are formed by chain growth polymerization, which in turn can be described by copolymerization statistics. From concentration-dependent measurements, derived copolymerization parameters and DFT calculations, a mechanism for self-assembly is developed that suggests a kinetically driven polymerization process in combination with thermodynamically controlled crystallization.

Keywords: Chain Growth Polymerization; Oligopyridine; Reaction Mechanisms; Scanning Tunneling Microscopy; Self-Assembly.