Two-dimensional nanotemplates as surface cues for the controlled assembly of organic molecules.

Controlled two-dimensional assembly of organic molecules can be successfully realized by meansof surface nanotemplates that provide surface cues for assembly upon adsorption. Examples of suchtemplates are nanostructured surfaces and organic porous networks. In this review, we discuss theformation and use of such templates for controlled molecular assembly. The formation of the organicporous network is typically based on non-covalent interactions, e.g., hydrogen bonds, dipole-dipoleinteractions, metal-organic coordination bonds together with substrate-mediated molecular interactions.The pores of the network can act as hosts for specific organic molecules. The chemical structureof the molecular building blocks of the porous network has a primary effect on the shape, size,and chemical reactivity of the cavities. Long-range mesoscale reconstructions can also be employedas surface nanotemplates based on the selective adsorption of atomic or molecular species at specificsurface sites. Scanning tunneling microscopy is the key tool to study the formation of the nanotemplatesas well as the effect of the template in the growth of the ordered organic structures. The reportedstudies contribute to build the rationale in the design and fabrication of two-dimensional organicnetworks. The topic covered in this review represents an important challenge in nanotechnology sincethese findings might have a wide range of applications, e.g., in electronics, sensing, and bio-recognition.