Unbalanced 2D Chiral Crystallization of Pentahelicene Propellers and Their Planarization into Nanographenes

Jan Voigt (1) , Myriam Roy (2) , Miloš Baljozović (1) , Christian Wäckerlin (1) , Yoann Coquerel (3) , Marc Gingras (2) , Karl‐heinz Ernst (1, 4, 5)

1 EMPA - Swiss Federal Laboratories for Materials Science and Technology [Dübendorf]
2 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
3 ISM2 - Institut des Sciences Moléculaires de Marseille
4 Nanosurf laboratory, institute of Physics
5 UZH - Universität Zürich [Zürich] = University of Zurich

The chiral self-assembly of trispentahelicene propellers on a gold surface has been investigated in ultrahigh vacuum by means of scanning tunneling micro- scopy and time-of-flight secondary ion mass spectrometry. The trispentahelicene propellers aggregate into mirror domains with an enantiomeric ratio of 2 : 1. Thermally induced cyclodehydrogenation leads to planarization into nanographenes, which self-assemble into closed-packed layers with two different azimuths. Further treatment induces in part dimerization and trimerization by intermolecular cyclodehydrogenation.

Mots clés: graphene; helicenes; on-surface chemistry; polycyclic aromatic hydrocarbons; scanning tunneling microscopy

Domaines: Chimie organique

Jan Voigt, Myriam Roy, Miloš Baljozović, Christian Wäckerlin, Yoann Coquerel, et al.. Unbalanced 2D Chiral Crystallization of Pentahelicene Propellers and Their Planarization into Nanographenes. Illustration. France. 2021. ⟨hal-03370289⟩