Two-dimensional supramolecular chemistry on surfaces

Self-assembly of two-dimensional supramolecular arrays on surfaces represents a significant challenge to chemists, materials scientists and physicists. This article highlights advances in using supramolecular interactions, particularly hydrogen bonding, to self-assemble such two-dimensional arrays on surfaces. Scanning-probe microscopies, particularly scanning tunnelling microscopy (STM), can be used to determine the precise molecular arrangement of the self-assembled structures allowing insight into the self-assembly process at the molecular level. The use of such supramolecular assemblies to trap guest species, mimicking host–guest chemistry in the solution phase, will also be discussed. Such images provide great insight into the advantages and restrictions of working in two dimensions in comparison to the solution phase or the solid state.