Supramolecular Anisotropy in a Surface-Confined Bicomponent System

Anisotropical engineering of surface-confined supramolecules provides a potential approach to precisely tweaking the properties and performance of low-dimensional molecular nanomaterials. Here, we report the construction of a surface-confined bicomponent supramolecular structure that features structural anisotropy by combined scanning tunneling microscopy and density functional theory studies. One-dimensional supramolecular ribbons formed by corannulene with either titanyl phthalocyanine or copper phthalocyanine exclusively extend along the equivalent ⟨11̅0⟩ directions on Ag(111). Such a supramolecular anisotropy is demonstrated as a result of the combined effects of molecule–substrate commensurability and intermolecular interaction relaxation, which leads to orientation-dependent energy cost for commensurate growth of the supramolecular ribbon on Ag(111). These findings provide insights into the mediation effect of the fine balance between the molecule–substrate and intermolecular interactions on the supramolecular structures, offering an efficient methodology for supramolecular anisotropical engineering.