Programming Supramolecular Assembly and Chirality in Two-Dimensional Dicarboxylate Networks on a Cu(100) Surface

Abstract

We report a comparative study on the 2D self-assembly of two related ditopic benzoic acid species, which have similar shape and endgroups but different backbone symmetry. High-resolution scanning tunneling microscopy data reveal how the symmetry information of molecular building blocks is readily expressed in the resulting chiral or nonchiral supramolecular networks. The underlying square Cu(100) surface steers network orientation and accounts for carboxylate formation, resulting in an unusual intermolecular hydrogen bond motif. Our results demonstrate that symmetry and chiral resolution in 2D supramolecular assembly can be controlled via the design of functional molecules and choice of substrate.

Surface-Template Assembly of Two-Dimensional Metal−Organic Coordination Networks

“…34,35 In the remaining part of the paper, the abbreviations TPA, BDA, and TDA refer to the deprotonated species. The iron was deposited after the molecules' deposition in order to minimize Fe exchange with the copper surface.…”

Influence of solvent on the chiral resolution of organic molecules on Au(111): EC-STM study of biphenyl dicarboxylic acid on Au(111) in an aqueous environment

“…al. reported that while symmetric 4,4' biphenyl-dicarboxylic acid (BPDA) molecules organize in networks on Cu(100) in an ultra-high vacuum (UHV), asymmetric stilbene dicarboxylic acid molecules experience mesoscopic chiral resolution, demonstrating the effect of molecular symmetry on chirality [25]. Chiral resolutions were also observed for smaller organic molecules on metal surfaces in the electrochemical environment [26][27][28].…”

Visualization of nucleation and growth of supramolecular networks on Cu(001) and Au(111)

“…Benzoic-acids adsorbed on single crystalline metal surfaces belong to the more frequently studied systems [10,11,12,13,14,15,16,17,18,19,20]. Here, the benzene rings of the molecules act as backbones, allowing a flat adsorption geometry on the metal substrates.…”

“…The molecules can thus interact by forming dimerized hydrogen bonds between the carboxylic (111), forming chain like structures with head-to-tail bonding [Adapted from [25]]. (b) BDA on Cu(001): the carboxylic acid group is deprotonated and head-to-tail bonding is not possible, rather carboxylate-phenyl bonds are formed [Adapted from [12]]. (c) BDA on Cu(001) co-adsorbed with Fe adatoms.…”

“…Hydrogen bonds, which can be highly selective, play an important role in the self-assembly process. One of the more frequently studied building blocks are benzoic acid groups [41,42,11,12,38,43,16,44]. It has been reported that benzoic acids adsorb on Cu(001) as deprotonated carboxylate species [41,42,11].…”