Supramolecular Nanopatterns of Molecular Spoked Wheels with Orthogonal Pillars: The Observation of a Fullerene Haze

Abstract

Molecular spoked wheels with intraannular functionalizable pillars are synthesized in a modular approach. The functionalities at their ends are variable, and a propargyl alcohol, a [6,6]‐phenyl‐C61‐butyrate, and a perylene monoimide are investigated. All compounds form two‐dimensional crystals on highly oriented pyrolytic graphite at the solid–liquid interface. As determined by submolecularly resolved scanning tunneling microscopy, the pillars adopt equilibrium distances of 6.0 nm. The fullerene has a residual mobility, limited by the length of the flexible connector unit. The experimental results are supported and rationalized by molecular dynamics simulations. These also show that, in contrast, the more rigidly attached perylene monoimide units remain oriented along the surface normal and maintain a smallest distance of 2 nm above the graphite substrate. The robust packing concept also holds for cocrystals with molecular hexagons that expand the pillar–pillar distances by 15 % and block unspecific intercalation.

Controlled Formation of Porous 2D Lattices from C3‐symmetric Ph6−Me‐Tribenzotriquinacene‐OAc3

“…Their actual structures and properties are governed by the nature and orientation of the substrate as well as the structural properties of the assembled molecules [5] . As the interaction between substrate and adsorbate as well as intermolecular interactions are typically based on rather weak forces such as π‐π interactions, dispersion forces, or hydrogen bonds in the presence of polar groups, [6] one viable strategy might be to steer the molecular orientation by external stimuli such that they form specific 2D lattices suitable for the desired superstructures [7] . Examples include graphene nanoribbons, flake‐like nanographenes as well as zigzag and holey structures.…”

“…[5] As the interaction between substrate and adsorbate as well as intermolecular interactions are typically based on rather weak forces such as π-π interactions, dispersion forces, or hydrogen bonds in the presence of polar groups, [6] one viable strategy might be to steer the molecular orientation by external stimuli such that they form specific 2D lattices suitable for the desired superstructures. [7] Examples include graphene nanoribbons, flake-like nanographenes as well as zigzag and holey structures. Perfectly flat, structurally-confined nanographenes have been produced on surfaces using self-assembly and on-surface reactions of mainly planar aromatic precursor molecules.…”