Structural adaptations of electrosprayed aromatic oligoamide foldamers on Ag(111)

Aromatic foldamers are promising for applications such as molecular recognition and molecular machinery. For many of these, defect free, 2D-crystaline monolayers are needed. To this end, submonolayers were prepared in ultra-high vacuum (UHV) on Ag(111) via electrospray controlled ion beam deposition (ES-CIBD). On the surface, the unfolded state is unambiguously identified by real-space single-molecule imaging using scanning tunnelling microscopy (STM) and it is found to assemble in regular structures. Stable molecular helices unexpectedly unfold to ribbons on a planar metal surface under ultra-high vacuum. These ribbons self-assemble in regular two-dimensional islands.