Landing-Energy-Controlled Surface Conformation of Electrosprayed Foldamer Molecules on Au(111).

Preserving the structural integrity of biomimetic foldamers upon surface deposition is essential for their integration into functional molecular architectures and devices. When assembled in well-ordered monolayers, these molecules can exhibit distinctive characteristics. In this study, we investigate the electrospray-controlled ion beam deposition of foldamer molecules in an ultrahigh vacuum (UHV) environment on an Au(111) surface and examine how their conformation depends on the mean landing energy during deposition. At a low mean landing energy of about 0.6 eV, intact foldamers are observed on the surface, whereas higher landing energies predominantly result in unfolded molecules and partially folded states. Additionally, annealing of the substrate converts folded conformations into unfolded ones. These results highlight the importance of soft-landing conditions to maintain hydrogen-bond-stabilized architectures on surfaces, offering a model platform for studying the structure-function relationship of surface-supported thermolabile biomolecules.