Hydrogen‐Bonded Molecular Networks of Melamine and Cyanuric Acid on Thin Films of NaCl on Au(111)

Self‐assembly of organized molecular structures on insulators is technologically very relevant, but in general rather challenging to achieve due to the comparatively weak molecule–substrate interactions. Here the self‐assembly of a bimolecular hydrogen‐bonded network formed by melamine (M) and cyanuric acid (CA) on ultrathin NaCl films grown on a Au(111) surface is reported. Using scanning tunneling microscopy under ultrahigh‐vacuum conditions it is demonstrated that it is possible to exploit strong intermolecular forces in the M–CA system, resulting from complementary triple hydrogen bonds, to grow 2D bimolecular networks on an ultrathin NaCl film that are stable at a relatively high temperature of ≈160 K and at a coverage below saturation of the first molecular monolayer. These hydrogen‐bonded structures on NaCl are identical to the self‐assembled structures observed for the M–CA system on Au(111), which indicates that the molecular self‐assembly is not significantly affected by the isolating NaCl substrate.