On-Surface Construction of Network Structures by the tert-Butyl-Substituted Organic Molecules

Abstract

On-surface formation of two-dimensional supramolecular network structures using molecular self-assembly has been an efficient and the most widely employed method. Through delicate modifying the molecular candidates with specific substituents, it is possible to build on-surface nanostructures according to one’s will. Here, from the interplay of high-resolution STM imaging and DFT calculations we have investigated role of the tert-butyl substituent in the formation of self-assembled network structures by planar aromatic molecules on metal surfaces. Our results demonstrate that the tert-butyl groups can change adsorption geometry of molecule from entirely flat-lying to a bit of upright-standing and vary the intermolecular interactions, which resulted in the formation of two-dimensional supramolecular network structures on both Au(111) and Ag(110). These findings further present that tert-butyl substituent could be a good candidate for fabricating on-surface self-assembled nanostructures from more general aromatic molecules.