Room-Temperature Scanning Tunneling Microscopy Manipulation of Single C₆₀ Molecules at the Liquid−Solid Interface:  Playing Nanosoccer

Abstract

This scanning tunneling microscopy (STM) study uses a supramolecular two-dimensional architecture of trimesic acid molecules adsorbed on a graphite substrate as a host for the incorporation of C60 as a molecular guest. By choosing a proper solvent, it was possible to verify that self-assembly of the host−guest structure can be accomplished at the liquid solid interface. Because of the ideal steric match with the molecular bearing of the host structure, C60 buckminster fullerenes are feasible guests. It was possible to coadsorb C60 within cavities of the open TMA structure from the liquid phase, and lateral manipulation of the molecular guest by the STM tip was demonstrated at room temperature. Because of the increased tip−sample interaction as a result of lower tunneling resistance, a transfer of a C60 molecule from one cavity of the host structure to an adjacent one was achieved.

Two-Dimensional Nanotemplates as Surface Cues for the Controlled Assembly of Organic Molecules

“…In fact, its molecular struc-ture allows the formation of supramolecular architectures, such as twodimensional porous networks via hydrogen bonding. After the first pioneering studies on the self-assembly of TMA performed in ultra high vacuum (UHV) on graphite [49] and Cu [50] surfaces, porous networks of TMA were also obtained at the solid/liquid interface [51], and the role of the solvents in addressing self-assembly was also investigated [52]. TMA adlayers were studied by electrochemical STM on Au(111) [53].…”

“…TMA porous networks and TMA/C 60 host-guest systems on graphite were studied at the liquid-solid interface in ambient conditions, using heptanoic acid as solvent [51]. Heptanoic acid is an ideal solvent for STM studies in solution because of its low conductivity and low vapor pressure.…”

Selective binding in different adsorption sites of a 2D covalent organic framework

“…1,2 In general, H/G networks rely on hierarchical interactions: the interactions binding the host together are stronger than the interactions binding the guest to the host. The host networks are typically sustained by hydrogen bonding, [3][4][5][6] van der Waals (vdW) forces, 7,8 or metal-ligand interactions, 9 whereas the adsorption of guest molecules mainly occurs via weaker interactions, typically dispersive interactions with the host as well as with the underlying substrate. However, moving away from selfassembled templates may offer some new opportunities for the stabilization of guest molecules.…”

Nanoelectrical analysis of single molecules and atomic-scale materials at the solid/liquid interface

“…This is typical of C 60 behaviour previously observed only under cryogenic temperatures (4-8 K; refs 32,33). Damping of molecular motion at room temperature has been reported previously for single C 60 molecules trapped on engineered porous organic templates 34 , graphene Moiré superlattices 35 and even macromolecules 36 on alkyl-coated surfaces. Imaging a single molecule under different positive biasing conditions with a fixed tunnel-current set point exhibited only a bias-dependent profile variation (Fig.…”