Controlled Construction of an Exquisite Three-Component Co-assembly Supramolecular Structure at the Liquid–Solid Interface

Abstract

A three-component supramolecular co-assembly structure formed at the liquid–solid interface by employing a shape-persistent π-conjugated macrocycle (16mer) and two guest molecules (COR and C60) is demonstrated. Scanning tunneling microscopy (STM) observations revealed that 16mer can serve as a versatile host molecule that can co-assemble with both COR and C60 guest molecules to form stable two-component structures, where the COR guest molecule filled in the gap between the side chains of adjacent 16mer molecules, and the C60 guest molecule entered the inner cavity of 16mer. It was found that the adding sequence of COR and C60 guest molecules is crucial to the resulting co-adsorption structure in the three-component system. To obtain the intriguing 16mer–COR–C60 three-component co-assembly structure, the 16mer and COR two-component co-assembly structure should first be constructed on a HOPG surface, followed by addition of C60. Based on the analysis of the STM results and the density functional theory (DFT) calculations, the formation mechanism of the assembled structures was revealed.

Progress in self-assemblies of macrocycles at the liquid/solid interface

“…On the other hand, different guest molecules may lead to competitively adsorb on the host template sites. 1 6mer is a shape-persistent macrocyclic molecule shown in figure 13(a) that is composed of a conjugated macrocycle and long alkoxy chains [63]. 1 6mer molecules form a periodic hexagonal pattern in the long range at the liquid/solid interface.…”

Self-Assembly of Triphenylamine Macrocycles and Co-assembly with Guest Molecules at the Liquid–Solid Interface Studied by STM: Influence of Different Side Chains on Host–Guest Interaction

“…23 Zhang et al constructed an interesting three-component co-assembly structure on the surface of HOPG by using a shape-stable πconjugated macrocycle and two guest molecules, COR and C60. 24 In fact, solvent molecules in the surface assembly of macrocycle molecules cannot be ignored. Tobe et al constructed a self-assembled molecular network of hexagonal pyridine macrocycles at the liquid−solid interface via electrostatic interactions, and the solvent molecules play a key role in the symmetry breaking of the macrocycle host framework in the host−guest complexation at the liquid−solid interface.…”

“…Many works have described the construction of 2D porous networks on surfaces based on carboxylic acid molecules, , and guest molecules could successfully induce a change in the morphology of the 2D self-assembly at the liquid–solid interface. − Moreover, many co-assembly systems based on macrocyclic molecules at the liquid–solid interface have been studied by STM technology. ,, Ni et al realized the controllable electrical switching effect of donor–acceptor conjugated macrocycles and fullerenes through thermal annealing . Zhang et al constructed an interesting three-component co-assembly structure on the surface of HOPG by using a shape-stable π-conjugated macrocycle and two guest molecules, COR and C60 . In fact, solvent molecules in the surface assembly of macrocycle molecules cannot be ignored.…”

Odd-Even Effect on Supramolecular Co-Assemblies: Control over the Two-Dimensional Self-Assemblies of a Fluorenone Derivative with Asymmetrically Substituted Alkyl Chains

“…In recent years, surface supramolecular self-assembly has been an active research area, aimed at the realization of nanoscale functional devices, such as organic photovoltaic cells, organic light-emitting diodes, and organic field-effect transistors. − In this context, inducing and regulating diverse self-assembly structures are subjects of interest. Researchers have explored the self-assembly polymorphs of π-conjugated molecules via changing the solvent, , concentration, , temperature, , scanning tunneling microscopy (STM) bias, − molecular functional group, , the length of the alkyl chains, , and the substrate. , The used substrate contains highly oriented pyrolytic graphite (HOPG), Au (111), Ag (111), Si (111), Cu (110), and so on. − In particular, STM is the widely used visualization tool due to its atomic-level resolution. The driving forces that stabilize the self-assembled nanostructures include the weak hydrogen bonds, van der Waals interaction, dipolar interaction, halogen bonds, and π–π attractions. − …”