Supramolecular Tessellations at Surfaces by Vertex Design

Abstract

Assembly and tessellation of organic species at surfaces are important for the design of advanced materials, particularly for the development of spontaneous self-assemblies of supramolecular systems of increasing complexity. However, there are few examples where the ability to steer the system between supramolecular tessellations has been achieved. Here, we demonstrate a series of steps to reduce and then restore molecular symmetry; those variations impact vertex symmetry and thus generate a series of tessellations that reflect the molecular symmetry. We deposit 4,4′-dihydroxybiphenyl on the Ag(111) surface, then anneal at specific temperatures to achieve stepwise dehydrogenation of the terminal hydroxyls. The symmetry of tessellation vertices in the self-assembled structure also changes, as characterized by scanning tunneling microscopy and synchrotron radiation photoemission spectroscopy. This control over vertex geometry and spontaneous tessellation structure extends our understanding of supramolecular design control and advances architectural complexity for the development of functional surfaces.

Complex k-uniform tilings by a simple bitopic precursor self-assembled on Ag(001) surface

“…Carboxylation presents a simple way to provide chemically distinct functional groups and, to a large extend, keeps the molecular geometry intact, enabling the incorporation of several binding motifs into a single phase. This is also stressed by a recent study where stepwise deprotonation of 4,4′-dihydroxybiphenyl leads to a rich variety of tessellations 30 . Importantly, in contrast with Archimedean tilings comprising metal-organic networks 24,25,36 , the tilings featuring hydrogen bonds presented here display nearly perfect long-range mesoscale order on micrometer length-scale.…”

“…The recent progress in the experimental realization of complex surface tessellations on an atomic and molecular level [7][8][9][10][11][12][13][14] is driven by the intriguing physical [15][16][17][18][19][20][21][22] and chemical 23 properties of these systems. In this respect, the supramolecular chemistry offers tools for engineering of distinct self-assembled surface geometries that present an expression of semiregular [24][25][26][27][28][29][30] , fractal [31][32][33][34][35] , quasicrystalline [36][37][38][39] , and random [3][4][5][6] tilings. Despite this effort, complex k-uniform tilings comprising a higher number of vertex types remain largely unexplored.…”

Structural Phase Transitions of Molecular Self-Assembly Driven by Nonbonded Metal Adatoms

“…The total energies calculated for a single molecule in the close-packed and the honeycomb structure are −1.608 eV and −1.584 eV, respectively (Table ). More detailed analyses suggest that the molecules in the honeycomb structure have a stronger adsorbate–substrate interaction, which could be attributed to the better molecule–substrate alignment . However, this energy is outweighed by the intermolecular interactions in the close-packed structure.…”

“…Structural transformation from a close-packed to low-density phase has been scarcely reported, , only for the cases where the formation of coordination or ionic bonds in the assemblies reduces the total energy of the molecular systems with lower density. In our study, the transformation from the close-packed structure to the honeycomb structure is not expected because of the fact that the self-assemblies only contain weak intermolecular hydrogen bonds and halogen bonds.…”

Complex supramolecular tessellations with on-surface self-synthesized C60 tiles through van der Waals interaction

“…According to previous studies, thermal annealing is an effective way for tuning molecular adsorption configurations and assembly. [34][35][36][37][38] Fig. 3 Thus, it is expected that more supramolecular tessellations can be fabricated through thermal treatment.…”