Molecular tuning of amino acids to form two-dimensional molecular networks driven by conformational preorganization.

We investigated the self-assembly of rationally designed γ-Phe on Au(111) using scanning tunneling microscopy with density functional theory calculations. In contrast to α-Phe, γ-Phe self-assembled into ring-shaped clusters (RSCs) and two-dimensional (2D) molecular domains. The better self-association tendency was attributed to conformational preorganization through intramolecular interaction between ammonium and carboxylate functionalities.