Beyond decorative'' 2D supramolecular self-assembly: strategies towards functional surfaces for nanotechnology

2D supramolecular self-assembly has emerged as a powerful tool in nanoscience for bottom-up fabrication of well-defined and long-range ordered two-dimensional (2D) molecular nanostructures at surfaces. Following an overview of the principles of this distinctive self-assembly process, this review focuses on recent strategies developed to go beyond surface nanopatterning and to provide functional surfaces. With an emphasis on the chemical engineering of the molecular building blocks constituting the adlayer, we show that besides supported nanoporous networks, a more promising approach lies in the upstanding 3D functional building blocks mounted on the substrate. We highlight the opportunities offered by graphene, a substrate for which non-covalent functionalization by supramolecular self-assembly represents a way to either control its electronic properties or provide a new functionality. Finally, future perspectives are addressed.