Bias-induced conformational switching of supramolecular networks of trimesic acid at the solid-liquid interface

Abstract

Using the tip of a scanning tunneling microscope, an electric field-induced reversible phase transition between two planar porous structures ("chickenwire" and "flower") of trimesic acid was accomplished at the nonanoic acid/highly oriented pyrolytic graphite interface. The chickenwire structure was exclusively observed for negative sample bias, while for positive sample bias only the more densely packed flower structure was found. We suggest that the slightly negatively charged carboxyl groups of the trimesic acid molecule are the determining factor for this observation: their adsorption behavior varies with the sample bias and is thus responsible for the switching behavior.

Nanoscale tailoring of supramolecular crystals via an oriented external electric field

“…Therefore, under a positive STM bias, more molecules arise from solution to the gap between the STM tip and substrate and thus the tendency of close packing takes place. 32 This is also consistent with the mechanism for the phase transitions, namely, the occurrence of the ( partial) deprotonation of the functional groups under a positive STM bias. Similar results were concluded from the TMA systems in our recent work.…”

“…Besides being an analytical tool, the stimuli and manipulations through STM are local, allowing us not only to visualize but also to manipulate the nucleation and growth of supramolecular assemblies in a real-time fashion. 31,32 With this methodology, we were able to grow 2D supramolecular architectures in a bottom-up single-crystal manner.…”

Supramolecular Chemistry: Host–Guest Molecular Complexes

“…Previously, many studies have been conducted via external induced stimuli referred to as “STM-induced phase transitions”. These molecules possess the intrinsic intramolecular dipole moment [ 135 , 136 , 137 ]. Recently, it was explored that phase switching can also occur in TMA, having a chicken-wire structure, an analogue to BTB, as discussed earlier ( Figure 1 ).…”

Origin of Solvent-Induced Polymorphism in Self-Assembly of Trimesic Acid Monolayers at Solid–Liquid Interfaces

“…This small, highly symmetric, and conformationally rigid tecton gives rise to an astonishingly large number of distinct structures and intriguing observations. [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] Here we concentrate on the solvent-induced polymorphism observed for the homologous series of fatty acid solvents on graphite, 26 as the first reported case of a phenomenon that turned out to be common. [4][5][6][7][8][9][10][11][12][13][14] Although our original publication dates back to the year 2005, no detailed account on the origin of this paradigmatic finding has been yet provided.…”